T25%201971%20Workshop%20Manual%2099 0945%20x[1]

User Manual: T25%201971%20Workshop%20Manual%2099-0945%20x[1]

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WORKSHOP

}IANUAt

FOR

250c.G. (l

SINGLE

5cu.in.)

CYLINDER

@ Copyright by

TRIUMPH E]{GINEERING CO. LTD.

MERIDEN WORKS . ALLESLEY . COVENTRY

TELEPHONEz 0203-20221

CVs 9AU .ENGLAND

TELEX: ..TRUSTy" 3130S

TELEGRAMS: ..TRUSTy', COVENTRY

Published July 197'l Publication Part No. 99-0945

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IMPORTANT NOTE

Any modifications to anyTriumph motorcycle made by you or to be

made by you in the future shall be held by our company to have been

modified at your own risk and responsibility and without either the

explicit or implied consent of Triumph Engineering Co. Ltd. or

Triumph Motorcycle Corporation. We will assume no liability,

obligation or responsibility for any defective or modified parts or

for the modified motorcycle itself, or for any claims, demands or

legal action for property damage or personal injuries which may

result from the modification of any Triumph motorcycle.

,'€ 'l

._-*_.*J-\

,*:lS'-\

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INTRODUCTION

THIS'manual has been compiled and prepared to provide the necessary service information for workshop,

fitter, technical staff and individual owner, wishing to carry out basic maintenance and repair work on the

TRIUMPH 250 c.c. MODEL T25T and T25SS.

GENERAL DATA for all models within the above range is provided in ready reference form, and a separate

section covering Service Tools is fully illustrated at the end of this manual.

The manual is divided into sections dealing with major assemblies, throughout the machine, each section sub-

divided into sequence order corresponding to normal operations of strip down, examination and rebuilding

p roced u re.

ENGINE AND FRAME NUMBERS

Note: The engine number is located on the left On later models the system of numbering is

side of the engine, immediately below the cylinder changed, and a prefix is added indicating the month

barrel flange. The number is stamped onto a and year of manufacture.

raised pad.

The first letter indicates the month of The second letter indicates the season

manufacture as follows:- year of manufacture as follows:-

A January C 1969

B February D 1970

C March E 1971

D April G 1972

E May H 1973

G June J 1974

H July K 19V5

J Augusr N 1976

K September P 1977

N October X 1978

P November A 1979

X December B 1980

The third Section is a numerical blocl< of five figures

which conrmence with engine number 001 00.

The fourth Section indicates the model' The frame number is stamped on the reft side of

Example Month Yeor Nurnber Model the frame, on the front engine mounting lug. Both

N C 001 00 T25T the engine and frame numbers should coincide.

GUARANTEE

Please refer to your local dealer or distributor where required for the latest terms of guarantee.

EASTERN U.S.A. DISTRIBUTORS WESTERN U.S.A. DISTRIBUTORS

TRIUMPH MOTORCYCLE CORPORATION, TRIUMPH MOTORCYCLE CORPORATION,

p.o. Box 6790, TowsoN, BALTTMORE 4, P.O. BOX 275,

MARYLAND 21704. EAST HUNTINGTON DRIVE,

Cables: Triumph Baltimore. DUARTE,

Telex:87728 CALIFORNIA 91010.

TELEX: 675469

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FACTORY SERVICE ARRANGEMENTS

UNITED KINGDOM ONLY

CORRESPONDENCE

Technical Advice, Guarantee Claims and Repairs

Communications dealing withany of these subjects should be addressed to the SERVICE DEPARTMENT.

TECHNICAL ADVICE

It will be appreciated how very difficult it is to diagnosetrouble by correspondence and this is made impossible

in many cases because the information sent to us is so scanty. Every possible point which may have some bear-

ing on the matter should be stated so that we can send a useful and detailed reply.

REPLACEMENT PARTS

Replacement parts are no longer supplied direct from the factory to the individual owner. They should be

obtained from the nearest local Triumph dealer.

There is a nation-wide network of stockists, a list of which is available from the factory on request.

REPAIRS

Before a motorcycle is sent to our Works an appointment must be made. This can be done by letter or

telephone. When an owner wishes to return his machine for guarantee repairs, he should first consult

his Dealer as we do not normally accept machines in our Repair Shop direct from private owners.

Frequently the Dealer can overcome the trouble without the delay and expense of sending the machine to

the Works. This avoids the machine being out of use for some days when it could be on the road. Where

parts such as cylinders, petrol tanks, etc., are forwarded for repair, they should be packed securely so as to

avoid damage in transit. The dealer's name and address should be enclosed together with full instrucrions.

ln the case of complete motorcycles, a label showing the dealer's name and address should always be attached

and all accessories such as tools, inflator, handlebar mirrors and other parts removed.

SERVICE EXCHANGE RECONDITIONED UNITS

A range of service exchange reconditioned units is available from the Factory Service Department. This

list includes petrol tanks, front forks, front and rear frames, clutch plates, brake shoes, etc., which are

supplied after the return of the original equipment for inspection and acceptance. Operation of this scheme

is maintained solely through the Dealer network.

ln all communications the full engine number complete with all prefix letters and

figures should be stated. This number will be found on the L.H. side of the crankcase

just below the cylinder flange.

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CONTENTS

GENERAL DATA

LUBRICATION SYSTEM

ENGIN E

CARBU RETTER

FRAME & ATTACHMENT DETAILS

TELESCOPIC FORK

WHEELS, BRAKES & TYRES

ELECTRICAL SYSTEM

SERVICE TOOLS

CONVERSION TABLES

SECTION

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TRIUMPH 250 c.c. BLAZER SS T25SS (U.S.A. only)

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TRAILBLAZER T25T (U.S.A. only)

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BLAZER SS T25SS (Home and General Export)

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%--

ENGINE TIMING DISC. PUSH OUT AND USE FOR VALVE TIMING IGNITION SETTING ETC,

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BLAZER

GENERAL DATA

BLAZER SS T25SS (USA)

TRAIL BLAZER T25T

SS T25SS (Home and General

250cc. ( 15 cu. ins.)

Export)

GD1

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GD GENERAL DATA

PISTON

Material

MODEL T25SS-BLAZER SS (USA ONLY)

ENGINE

Compression ratio

Clearance (bottom of skirt)

Clearance (top of skirt) ...

(Both measured on malor axis)

HG413 Aluminium alloy

9.5:1

'0023/'0028 in. (.058421.071'1 2 mm.)

.0042/'0053 in. (..106681.13462 mm.)

PISTON RltlGS

Material-compression (top) H.G.22 cast iron

Material-compression (centre)... H.G.22 cast iron

Material-scraper... H.G.22 cast iron

Radial width-compression (top and centre) ... 0.101510.1074 in. (2.57712.729 mm.)

Radial width-scraper. 0'101510.1074 in. (2.57712.729 mm.)

Depth-compression (top and centre)... 0.0615/0.0625 in. (1 .562711.588 mm.)

Depth-scraper ... 0.12410'125 in. (3.14913.175 mrn.)

Clearance in groove '00t7.993 in. (.0254/.0762 mm.)

Fitted gap-(maximum) ... .01 3 in. (.3302 mm.)

Fitted gap-(minimum) ... .009 in. (.2283 mm.)

Connecting rod (length between centres) 5.312 in.'(134.92 mm.)

lnternal dia. of small end... .6892 in. (j7.51 mm.)

OIL PUMP

Pump body material Zinc base alloy

fYp" Double gear

Driveratio... 1:4

Non-return valve spring (free length) ... '625 in. (15.875 mm.)

Non-return valve spring ball (diameter) .25 in. (6.35 mm.)

Oil pressure release valve spring (free length) .6094 in. (15.4781 mm.)

Oil pressure release valve ball (diameter) '3125 in. (7.9375 mm.)

CAMSHAFT

Journal diameter (right and left-hand) ... .74801.7485 in. (18.9992119.0119 mm.)

Cam lift (inlet) .345 in. (8.763 mm.)

Cam lift (exhaust)... .336 in. (8.534 mm.)

Base circle radius ... .906 in. (23 0124 mm.)

CAMSHAFT BEARING BUSHES

Bore diameter (fitted) .. .74921.7497 in. (19.0297119.04238 mm.)

Outside diameter...

Camshaft clearance

CRANKSHAFT

End float

VALVES

Seat angle (inclusive) 90'

ueaa aiamJter (inteil

Head diameter (exhaust)... 1'3'1211.317 in. (33.3248/33.4518 mm.)

Stem diameter (inlet) '3095i.3100 in. (7'86'117:874 mm.)

Stem diameter (exhaust)... .3090/.3095 in. (7'848/7.861 mm.)

VALVE GUIDES

Material Hidural 5

Bore diameter .31201.3130 in. (7.9248/7.950 mm.)

Outside diameter ... '5005/.5010 in. (12.7127112.7254 mm.)

Length 1'844 in. (46.8276 mm.)

Cylinder head interference fit ... .0015/.0025 in. (.038'l-3.0635 mm.)

VALVE SPRINGS

Free length (inner) 1.400 in. (35.56 mm.)

Free length (outer) 1.750 in. (44.45 mm.)

Fitted length (inner) 1.262 in. (32.0548 mm.)

Fitted length (outer) 1.370 in. (34.798 mm.)

VALVE TIMING

Tappets set to.015 in. (.381 mm.) for checking purposes only:

lnlet opens B.T.D.C. 51"

lnlet closes A.B.D.C. 68"

Exhaust opens B.B.D.C. ... 7S

Exhaust closes A.T.D.C. ... 37'

TAPPET CLEARANCE CoId

lnlet... .008 in. (.2032 mm.)

Exhaust .0'10 in. (.254 mm.)

IGNITION TIMING

Piston position (B.T.D.C.) fully advanced .342 in. (8'6868 mm.)

Crankshaft position (B.T.D.C.) fully advanced 37"

contact breaker gap setting .015 in. (.381 mm.)

7 4921.7497 in. (19.0297 119.04238 m

908 1.909 in. (23'0632123.0886 mm.)

0007 l'0017 in. (.01778

1.0431 8 mm.)

'0007 l'0017 in. (.01778

1.0431 8 mm.)

'002/.00s in. (.0508/.127 mm.)

GD2

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GENERAL DATA GD

Throttle valve

Nominal choke size

Throttle slide return spring (free length)

-th ird

-second

-fi rst

Champion N3

.020/.025 in. (.508/.635 mm.)

14 mm. dia.X.75 in. reach (19.05 mm.)

Aluminium alloy with ausrenitic iron

liner

67 mm.

70 mm.

0'010 and 0.020 in. (0.254 and 0.508 mm.)

Aluminium alloy

1.125 in. (28.575 mm.)

1.25 in. (31'75 mm.)

Amal 928/20 (concentric float chamber)

190

.106 in. (2'69 mm.)

28 mm.

2'5 in. (63.5 mm.)

Multi-plate with integral cush drive

.167 in. (4.242 mm.\

1.65685 in. (42.0687 mm.1

9.0 in. (228.6 mm.)

.1875 in. (4.7025 mm.)

1.0

1.24

1.65

2.65

6.89

8.54

11.37

18-26

23 teeth

52 teeth

1 7 teeth

52 teeth

SPARK PLUG

Type

G'.i.etting(minimum/maximumj ..'.' :::

Thread size

CYLINDER BARREL

Material

Bore size (standard)

Stroke

Oversizes ...

CYLINDER HEAD

Material

lnlet port size

Exhaust port size ...

CARBURETTER

TyPe

Main jet

Needle jet size

Needle position ...

BEARING DIMENSIONS

Clutch roller (25) .1875x.1875 in. (4.7A25x4.7025 mm.)

Con-rod big-end bearing-running clearance... .0005/.0010 in. (.0127/.0254 mm.)

Con-rod big-end-crank diameter 1.437511.4380 in. (36.5125/36.5252 mm.)

Crank undersizes ... .0i0, .020 and .030 in. (.254, .508 and

.762 mm.)

Con-rod small-end bush (bore) ... .68901.6894 in. (17.5006/17.6108 mm.)

Crankcase bearing (drive-side) ... 25x62x17 mm.

Crankcase bearing (timing-side) 25x62x17 mm.

Crankshaft dlameter (drive-side and timing-side) ... -984'1 1.9844 in. (24.9961 122'0038 mm.)

Gearbox layshaft bearings (drive-side and timing-side) ... 0.5x.625x.8125 in. (12.7x'15.875x

20.6375 mm.)

Gearbox layshaft diameter (drive-side and timing-side) ... -62451.625 in. (i5.8623/15.8750 mm.)

Gearbox mainshaft bearing (drive-side) 30 x 62 x 16 mrir.

Gearbox mainshaft bearing (timing-side) .625x1.5625x.4375 in. (15.875 x

39.2875x11.1125 mm.)

Gearbox mainshaft diameter (drive-side) .74851.749 in. ('19.0119119.0246 mm.)

Gearbox mainshaft diameter (ti.mjng-side) .62451.625 in. (15.8623/15.8750 mm.)

Gearbox sleeve pinion (internal diameter) .7521:79 in. (19.1008/19.,1262 mm.)'

Gearbox sleeve pinion (external diameter) '1.17911.180 ii. (29-9466129.9720 m;n.)

Gudgeon pin diameter '6882/.6885 in. (17.4803117.4879 mm.)

TRANSMISSION

CLUTCH

TyP"

Number of plates:

Driving (bonded segments)

Driven (plain)

Overall thickness of driving plate and segments

Clutch springs

Free length of springs

Clutch push rod (length)

Clutch push rod (diameter)

GEAR RATIOS

Gearbox-top

-th ird

-second

-first

Overall-top

SPR()CKETS

Engi ne

Clutch

Gearbox

Rear wheel...

GD3

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GD GENERAL DATA

CI.IAIN SIZES

Primary

Transmission

FRAME AND FITTINGS

FRONT FORKS

Type

Siiings-free length ... ... ... ...

-Compressed Iength

-fitted length

-Spring rate

-Max. lead

-colour identification ...

Stanchion diameter top ...

Stanchion diameter bottom

Stanchion internal bore ...

Outer member bore size

REAR DAMPERS

TyP"

Springs-free length

WHEELS, BRAKES AND TYRES

wM2-18

Duplex '375 in. x70 links

0.625 in.x108 links

Coil-spring (hydraulically damped)

19'1 in. (48'5 mm.)

11.4 in. (289.5 mm,)

18.5 in. (217 mm.)

25 lb/in.

194 lbs. (45.5 l<g.)

Orange

1.355/1.350 in.(34 4/34'3 mm.)

1 .3610/1 .360s (34.6/34'ss mm.)

1.09s/1.089 in. (27'8127'66 mm.)

1.36511.363 in. (27'05/27 mm.)

Coil-spring (hydraulically damped)

8.40 in. (213'36 mm.)

100 lb./in.

Green/pink (applies both to chrome or

black springs)

Torrington needle roller bearings 81616

2 off

.801i.800 in. (20'35/20'32 mm.)

1.0000/.999s in. (25'4125'388 mm.)

.1991.197 in. (5'05/4'99 mm.)

20x47 x14 mm. Ball journal

20x47 x14 mm. Ball iournal

.87 40 l'87 45 in. (22'199 122'21 2 mm.)

.87 45 1.87 50 in. (22.212 122'225 mm.)

.68s/.686 in. (17.399117.424 mm.)

6 in. (152 mm.)

.875 in. (22'2 mm.)

7 in. (177.8 mm.)

1.125 in. (28'5 mm.)

9.8 in.z (63'3 cmz)

17.4 in.z (112'4 cmz\

3.25x18 in. (82'55x457'2 mm.)

3.50x18 in. (88'9x457'2 mm.)

22 p.s.i. (1'547 kg./sq. cm.)

24 p.s.i. ('l'685 kg./sq.cm.)

2:1

-spring rate

-colour identification

S\^/INGING ARM

Bearing type

Spindle diameter ...

Bearing sleeve diameter

Thrust washer depth

\^/HEELS

Rim size and type (front)

Rim size and type (rear) .

Spoke sizes:

Front (1 0)

Front (20)

Rear (1 0)

Rear (20)

10 s.w.g. x6'3 in. ('165 mm.)

10 s.w.gx6.4 in. (167.6 mm.)

10 s.w.g. x7'7 in. (195'6 mm.)

10 s.w.g. x 5'7 in. ('144'8 mm.)

10 s.w.g. x4.5 in. (114 mm.)

10 s.w.g.x6'9 in. (175 mm.)

\^,HEEL BEARINGS

BRAKES

Front (left and right hand)

Rear (left and right-hand)

Rear brake drum ...

Spindle diameter (front)

sii" Ji" aii.uter ire".,'left-hanJj

Spindle diameter (rear, right-hand)

Front (diameter) single lead

Front (width) single leading

Rear (diameter) ...

:r) single leading shoe

single leading shoe

Rear (diameter)

Rear (width)

Lining thickness front

Lining thickness rear

TYRES

Size (front)...

Size (rear) ...

Pressu re (front)

Pressure (rear)

Speedometer drive ratio...

GD4

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GENERAL DATA GD

12 VOLT ELECTRICAL EAUIPMENT

Battery

Coil

Contact breaker unit

Generator

Generator output

Horn

Rectifier

Zener Diode

e"it.j"udlu.p (main) ... ...

-headlamp (pilot)...

-warning lamps

-stop-tail lamp

Condenser...

Lucas PUZ5A

Lucas MA.12

Lucas 6CA

Lucas RM.21

1'15 watt

Lucas 6H

Lucas 2DS.506

Lucas 2D.715

40/50 watt Lucas 380

6 watt Lucas 989

2 watt

6121 wart

Lucas 5444'1 582

Lucas 2MC

Lucas 8FL

Lucas MCH66

Lucas 1 695A

Lucas 1 695,4

Lucas 1 4695A

Lucas 1 I 85A

Capacitor ..

Flasher Unit

Headlamp...

Handlebar switch (right)..

Handlebar switch (left) ...

lgnition switch

Rear stop switch ...

Fuel tank ..,

Oil reservoir

Gearbox

CAPACITIES

Primary chaincase

Front fork (each leg)

BASIC DI MENSIONS

\A/heelbase...

Overall length

Handlebar width

Seat height

Ground clearance.

Overall height

WEIGHTS

Machine unladen ...

Engine/gearbox unit (less carburetter)..

TORQUE SETTINGS

A pplication

Carburetter Flange nuts ...

Clutch centre nut...

Conn-rod end cap nuts

Cranl<shaft pinion nut

Cylinder barrel nuts

Fork leg cap nuts ...

Fork leg pinch bolts

Kickstart ratchet nut

Oil pump stud nuts

Rotor fixing nut ...

Valve cover nuts ...

Spark plug...

Flywheel bolts

Stator nut ...

Counter shaft sprocket nut

Fork stanchion end plug ...

Handlebar clamp bolts

2j U.S. galls (14'774litres)

4 pints/4'8 U.S. (2'273 Iitres)

0.5 pint/0.6 U.S. (284 litre)

0.25 pint/0'3 U.S. ("142 Iitre)

0.34 pint/0.4 U.S. (.1893 litre)

54 in. (137 cm.)

85 in. (216 cm.)

29 in. (73.5 cm.)

32 in. (81.28 cm.)

7 in. (18 cm.)

43'5 in. (110'5 mm.)

280 lbs. (131 kg.)

85 lbs. (39 kg.)

Torq ue

10 lb. ft. (1 .38 kg. m.)

60 lb. ft. (8.3 kg. m.)

27 lb. ft. (3.7 kg. m.)

40 lb. ft. (5.s kg. m.)

20 lb. ft. (2.8 kg. m.)

40 lb. ft. (5.5 kg. m.)

1e120 tb. ft. (2.s/2'8 kg.m.)

50 lb. ft. (6.9 kg. m.)

6 lb. ft. (0'8 kg. m.)

60 lb. ft. (8'3 lcg. m.)

10 Ib. ft. (1.a kg. m.)

14 lb. rt. (1.9 kg. m.)

32 lb. ft. (4.4 kg. m.)

20 lb. ft. (2.8 kg. m.)

75lb.ft. (10'4 kg. m.)

2s lb. ft. (3.4s kg. m.)

12 lb. ft. (1.6 kg. m.)

GD5

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GD GENERAL DATA

GENERAL DATA

T25SS HOME AND GENERAL EXPORT

For data not supplied here refer to General Data for T25SS U.S.A.

\^/HEELS

Spoke sizes:

Front (20)

t=ront (t oi ..:

Front (1 0)

BRAKES

10 s.w.g. x6.9 in. (175.26 mm.)

10 s.w.g. y 4.9 in. (,124.46 mn.\

10 s.w.g. , 4.6 in. (116.8 mm.)

WHEELS, BRAKES

.....::.:::

AND TYRES

Front (diameter) twin leading shoe 8 in. (203 mm.)

CAPACITIES

Fuel tank 2 galls. (9 liters)

T25T U.S.A. ONLY

For data not supplied here refer to General Data for T25SS U.S.A.

WHEELS AND TYRES

\MHEELS

Spoke sizes:

Front (10)

rront itoj ... ..: ... ::. ...

, Front (20)

RIM SIZE

Front

Rear

Tyre size:

Front ...

Rear ...

Rear Chain No. of links ...

Gearbox Sprocket

Speedometer Drive ratio

OVERHAUL GEAR RATIOS

ToP...

3rd ...

2nd ...

1st ...

Weight (unladen) ...

DIMENSIONS

Ground clearance...

10 s.w.9.x7.2 in. (183 mm.)

10 s.w.g. x7.8 in. (198 mm.)

10 s.w.g.x8.6 in. (218.5 mm.)

WM1 x20

WM3 x 18

3 x 20 Trials universal

4 x 18 Trials universal

107

16r

21 :10

7.35

9.10

12-13

19.49

287 Ibs (130.2 kg.)

7ins. ('195.5 mm.)

GD6

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GENERAL DATA GD

GEAR RATIO CALCULATIONS

PRIMARY

CHAINWHEEL

ENG INE

SP R OCKET GEARBOX

SPROCKET

Fig. G.D.1. Arrangement of sprockets.

REAR WHEEL

SPROC KET

To find the gear ratios of a machine, calculate the top gear as follows:-

Divide the number of teeth on the primary chainwheel by the number of teeth on the engine sprocket

and multiply the result, by the number of teeth on the rear wheel sprocket, divided by the number of teeth

on the gearbox sprocket, as example:-

clutch sprocket (52) rear wheel sprocket (52) 2704

6.92

engine sprocket (23) georbox sprocket (17) 391

To find the intermediate gear ratio, multiply the overall top gear by the internal gear ratio concerned,

as exam ple:-

top gear 6.92x bottom geor internol rotio 2.65:18.15 bottom geor overoll rotio

layshaft gear mainshaft toP geor

Gearbox internal ratio

moinshoft geor loyshoft top geor

(layshoft 3rd) 19f (moinshoft top) 227

TI78A

as example:-

(moinshaft 3rd) 247 (layshoft top) 147

1'245

GD7

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SECTION A

LUBRICATION SYSTEM

INDEX

SECTION

A1 ROUTINE LUBRICATION

A2 RECOMMENDED LUBRICANTS

A3 ENGINE LUBRICATION SYSTEM

A4 CHANGING THE OIL AND CLEANING THE FILTERS

A5 SCAVENGE NON-RETURN VALVE

A5 FEED NON-RETURN VALVE

A7 CRANKCASE OIL PIPE UNION

A8 OIL PRESSURE RELEASE VALVE

A9 LOW OIL PRESSURE

A1O SYPHONING

All DISMANTLING AND RE.ASSEMBLING THE OIL PUMP

412 CONTACT BREAKER

A13 GEARBOX LUBRICATION

A.14 PRIMARY DRIVE

415 REAR CHAIN

l.16 STEERING HEAD

417 TELESCOPIC FORK

4,18 WHEEL BEARINGS

419 LUBRICATING THE CONTROL CABLES

A2O SPEEDOMETER CABLE

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ALUBRICATION

SECTION AI

ROUTINE LUBRICATION

Ref. No.

Weekly

1 Check oil reservoir level

7 Grease brake pedal pivot

8 Oil exposed cables and control rod ioints

Every 500 Miles (800 Km.)

3 Check oil level in primary chaincase

Every 2,000 Miles (3,200 Km.)

I Drain and refill the oil reservoir

2 Check oil level in gearbox

10 Clean the oil filters

11 Lubricate prop stand (oil)

6 Grease bral<e cam spindle(s)

Fig. A1. Lubrication points.

(Numbers in circles refer to right side of machine;

numbers in squares refer to left side of machine)

Ref. No.

6 Grease rear brake cam spindle

12 Lubricate rear chain

Every 3,000 Miles (4,800 Km.)

1 3 Lubricate auto advance

14 Lubricate contact breaker cam

16 Renew disposable oil filter

Every 5,000 Miles (8,000 Krn.)

15 Grease speedometer drive cable

2 Drain and refill gearbox

3 Drain and refill primary chaincase

9 Drain and refill front forlcs

Every 10,000 Miles (16,000 Km.)

4 Grease wheel bearings

5 Grease steering head bearings

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LUBRICATION A

SECTION A2

RECOMMENDED LUBRICANTS (All Markets)

Engine

Primary Chaincase

Wheel Bearings,

Swinging Fork

and Steering Races

Easing Rusted Parts

Mobiioil

Super

Mobilgrease MP

Mobil Handy

oit

| .orr*or_

I Castrol GTX

1".

I Castrol XL_

Castrolite

Castrol

Penetrati

B.P. Gear Oil

SAE 90 EP

Esso Gear Oil

GX 901140

Shell Super

Motor Oil

Shell Super

Motor Oil

Havoline

Motor Oil

20w/s0

Havol i ne

Motor Oil

10w/30

Sl*il sph-r" l-llut.ig"".

Castrol

HyPoy

Mobilube

GX 90 Lu bricant

EP 90

Wheel Bearings, I

Swinging Fork I

and Steering Races

Marfak

All Purpose

G raphited

Penetrati

Easing Rusted

Parts

Duckham's

Adpenol

Penetrating Oil

Duckham's

Q20/s0

I Filtrate super I

I Lirhium Grease I

: Glide I Shell Donax T.7.

Esso I sn"tt

ipurpose I Retinax A

ease H I

gr* f tt*

Penetratine Oil I Easine Oil

Esso

M ulti Pu rPose

Grease H

APPROVED LUBRICANTS (All Markets)

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ALUBRICATION

SECTION A3

ENGINE LUBRICATION SYSTEM

The engine lubrication system is of the dry sump

type, i.e., the oil is fed by gravity from a reservoir to

a double-gear pump situated in the crankcase base at

the right-hand side (see Flg. A2).

The top set of gears in the pump draws oil from the

reservoir through a gauze filter and circulates it

under pressure, past a pressure release valve (D) a

non-return valve (A) and through the drilled crank-

shaft to the big-end bearing. Excess oil is thrown off

by centrifugal force, on to the cylinder walls and

the underside of the piston (to lubricate the

gudgeon pin) and fills various wells to lubricate the

camshaft and gears. An oil pressure indicator switch

is incorporated into the feed system (B).

After lubricating the various internal components of

the engine, the oil drains down into the crankcase.

From here the lower, and larger set of pump gears

draws oil from the gauze sump filter through

another non-return valve (C) and pumps it back to

the reservoir at a greater rate than that of the feed

side. This ensures that the sump never floods; hence

the term "dry sump".

CHANGING THE OIL AND

The oil In new or reconditioned engines should be

changed at 250,500 and 1,000 mile (400,800, 1,500

km.) intervals during the running-in period and

thereafter as stated in Section 41.

It is always advisable to drain the oil when it is warm

as it will flow more readily.

Remove the cranl<case undershield. This is retained

by two bolts.

Fig. A2. Engine lubrication system showing ball valves

The oil return pipe is tapped at the crankcase union

to provide a supply ofoil at low pressure to the valve

rocker gear.

The oil is fed through the rocker shafts, lubricating

the rocker ball pins, adiuster screws and finally the

tappets as it drains back into the cranlccase.

SECTION A4

CLEANING THE FILTERS

Remove the oil reservclir filler cap that is situated

behind the head lug. Remove the filter from the

reservoir; this is screwed into the base of the front

frame down tube, and then drain the oil inro a

suitable receptacle (See Fig. A3). This operation only

allows 1f; pints of oil to drain out. The remainder of

the oil is drained by means of a plug situated at the

rearmost part of the top main frame tube. To gain

access to this plug first remove the right hand side

panel by means of the two quick release fasteners.

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LUBRICATION

,''l

there is any sign of damage to the old gasket, replace

it on reassembly. Replace the undershield. Refill the

reservoir with engine oil in accordance with the

recommendations on page A3. The reservoir caPa-

city is 4 pints. Refit the oil cap.

An external filter is situated at the rear ofthe gear-

box and is bolted to the rear engine plate, using two

self-locking nuts. The centre bolt retaining the

filter housing lies at the base of the filter and is

accessable from underneath the ma.chine. The ele-

ment is disposable and should be replaced at the

interval shown on page A2..

Fig. A3. Oil reservoir and dipstick.

Remove the plug and allow the oil to drain onto a

suitable chute and into a convenient receptacle.

(A chute can be easily constructed from a piece of

cardboard shaped into a trough.) Clean the reser-

voir filter with fuel and replace. The gasket should

be replaced to ensure a good oil tight joint. Again

using a suitable container to catch the oil, unscrew

the four self-locking nuts holding the sump filter to

the crankcase and remove the filter. Allow the oilto

drain, wash the filter thoroughly in petrol and clean

the joint faces between the filter and crankcase. lf

-5 ll

--b

I FILTER HEAD

2 SEAL

3 'O' RING

4 PLATE

5 C|RCLIP

6 FILTER

7 PLATE

8 'O' RING

9 WASHER

IO SPRING

II BODY

12 BOLT

13 cltP

14 WASHER

Fig. A.4. Oil Filter

SECTION A5

SCAVENGE NON.RETURN VALVE

Whilst changing the oil it is a good Point to check

the scavenge pipe non-return valve for correct

operation. Using a pieceof wire, Push the ball upoff

its seating and allow it to drop of its own weight' lf

the ballwill not drop it indicates a build-up of sludge

which can usually be cleared by immersing the PiPe

in petrol for a short period. Check for crushing of

the filter screen in the area of the scavenge pipe

prior to re-assembly.

Fig. A5. Scavenge Non-return Valve

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LUBRICATION

SECTION A6

FEED NON.RETURN VALVE

lf there has been a tendency for the crankcase to fill

with oil after standing overnight, so causing the

engine to emit clouds of smoke when started, it is

quite possible that the feed line non-return valve is

OIL PRESSURE

The oil pressure release valve is very reliable and

should regu!re no maintenance orher than cleaning.

It is situated on the front of the crankcase (see

Fig. A7). Oil pressure is governed by the single

spring situated within the valve body. When the

sprlng is removed it can be checked for compressive

strength by measuring the Iength and checking

against the figure given in General Data.

When the valve has been removed the hexagonal

domed cap can be unscrewed from the main body,

not seating properly thus

from the reservoir. This

timing cover described in

allowing oil to run back

is the valve in the inner

Section A10.

UNION

*Q?Trr@

SECTION A8

SECTION A7

CRANKCASE OIL PIPE

The oil pipes are individually screwed into the

crankcase. To remove the pipes from the crankcase,

first of all disconnect the rubber take-off pipes by

loosening the securing clips. Then loosen the two

locknuts and unscrew the oil pipes from the crank-

case. When reassembling ensure that the threads

on the oil pipes are thorough!y cleaned in fuel.

Note: On machines subsequent to engine No.

CE.07500 T25T, a shorter return rubber pipe was

used. lt can make correct assernbly of the rubber

pipe onto the union difflcult, therefore care must be

taken to ensure that the pipe is pushed well onto the

union before the tightening the clip.

14)r*-

afu6h w(G;

Fig. A5. Crankcase oil pipe union

RELEASE VALVE

so releasing the piston which should be withdrawn.

Thoroughly clean all parts !n paraffin (keros.ne) and

inspect for wear. The piston should be checked for

possible scoring and the springs for signs offracture

and also length. To reassemble the release valve

unit offer the piston into the valve body and screw

on the valve cap with new fibre washers. Similarly,

when screwing the release valve unit into the

crankcase, fit a new fibre washer'between the

release valve body and the crankcase.

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LUBRICATION

Fig. .A7. Pressure release valve

(5) Examine the crankshaft oil seal and retainirrg

circlip as described in Section B.

(6) Ensure that both oil way plugs shown in Fig. A8

are screwed flush with the casting, and are

secured by centre punching the alloy casting

into both ends of each screwdriver slot.

(7) Remove the oil pump and measure the exposed

length of the locating dowels. lf this length is

not $in. less than the depth of counterbore in

the pump body, the dowels must be shortened

to ensure ProPer mating.

(8) lf the previous examinations prove un satis-

factory the oil pump should be checked as

described in Section 41 1. l-he correct pump

should have "S" stamped on the top spindle

housing. lf "V" is shown the pump must be

replaced with the correct type.

SECTION A9

LO\tr OIL PRESSURE

Normal oil pressure when the engine is hot should

be 60i75 lb./sq. in. at 4000/4500 r.p.m. This is

indicated by fitting an oil pressure gauge in place of

the oil pressure switch

lf the oil pressure is below the quoted figure the

following procedure should be followed:

(1) Ensure that the oil level in the reservoir is above

the minimum line.

(2) Remcve both the oil reservoir and sump filters

and thoroughly clean to ensure a free passage of

oil.

(3) Ensure that the oil pipes are correctly con-

nected, i.e. not reversed.

(4) Remove and examine the pressure release valve

as mentioned in Section A8.

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LUBRICATION

SECTION AIO

SYPHONING

This, one of the more common troubles, happens

when one of the non-return ball valves is sticking

off its seating. lt can also be caused by a badly worn

pump or one which is loose on its mounting.

lndications of syphoning are clouds of smoke from

the exhaust when the engine is first started after

standing overnight.

The feed Iine non-return valve consists ofa ball and

spring and is located in the inner timing cover (see

Fig. A8). After unscrewing the retaining plug, the

valve spring and ball can be removed for examina-

tion.

Should there be any doubt about the condition of

the valve components renew them, since they are

quite inexpensive.

The non-return valve in the scavenge pipe is des-

cribed on page A5.

Fig. A8, Non.return valve

REBUILDING THE PUMP

Absolute cleanliness is essential when rebuilding

the oil pump.

lnsert the driving spindle (with fixed gear) into

pump top cover, fit the worm drive and secure in

position with nut and spring washer.

Fit the driven spindle and gear into the cover. Place

the assembly on top of the pump body and insert the

lower gears. Apply clean oil to the gears and refit

the base plate. Check that the spindle and gears

rotate easily before tightening the four fixing screws.

Finally, check that the joint surfaces are parallel

since if the housing face is not level, it will be

distorted when bolted to the crankcase and may

prevent the pump from working.

SECTION AII

DISMANTLING AND REASSEMBLING THE OIL PU MP

Having removed the oil pump from the engine, take

out the four screws from base of pump, releasing the

base plate and top cover from the pump body.

The driving spindle and driving worm gear are

secured to the top cover with one nut and spring

washer. Before removing the worm gear, make

careful note of the way in which it is fitted to assist

in reassembly.

Wash all the parts thoroughly in petrol and allow to

dry before examining. Look for foreign matter

jammed in the gear teeth and deep score marks in

the pump body. These will be evident if the oil

changing has been neglected. Slight marks can be

ignored, but any metal embedded in the gear teeth

must be removed.

The most likely point of wear will be found on the

driving gear teeth; if these are worn to the extent

that the sharp edges have gone then they must be

renewed.

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LUBRICATION

CRANKCASE BREATHER

A short crankcase breather pipe emerges from the

timing case alongside the clutch cable abutment

(See Fig. 410). lt is most important that periodic

checks are made to ensure that this pipe remains

u nobst ructed.

When a machine is used in competition events or

at continued high speeds, it may be necessary to

provide a pressure outlet at the gearbox to prevent

oil leakage. This can be accomplished by drilling

a small hole through the oil filler plug.

Fig. A10. breather

ffis

Fig. A9. Oil pump exploded

Crankcase

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ALUBRICATION

SECTION AI2

CONTACT BREAKER

The contact breaker is situated on the outer timing

cover and it is essential that no engine oil gets into

the contact breaker housing. To prevent this, there

is an oil seal pressed into the inner timing cover

behind the auto-advance unit, spring side towards

the engine.

Lubrication ofthe contact breaker cam and the auto-

advance unit pivot points, however, is necessary'

The contact breal<er moving point has a nylon heel

which requires lubrication and for this PurPose

there is a felt lubricating wicl< resting on the cam

adjacent to the heel. lnitially this is treated with

Shell Retinax A grease, and at 2,000 mile intervals,

3 drops of clean engine oil should be added to the

wick at the opposite end to the cam.

To lubricate the auto-advance unit it is necessary

to remove the contact breaker plate. First mark

across the plate and the housing so that it can be

replaced in exactly the same Position. Take out the

fixing screws and withdraw the contact breaker

plate.

The pivot points ofthe auto-advance unit should be

lightly oiled, at 5,000 mile (8,000 km.) intervals'

Fig. Alt. Contact breaker

After lubricating, replace the plate to the marks, but

if the timing has been upset, follow the instructions

in Section 829.

Add grease here

SECTION AI3

GEARBOX LUBRICATION

The gearbox, having its own oilbath, is independent

of the engi ne for I u brication but, for the same reason'

the oil level must be checked and any loss due to

leakage made good.

For this purpose a nylon filler plug with diPstick is

fitted. The dipstick has a line marking only to

indicate the correct oil level.

The layshaft gears run in the oilbatn and oil being

carried by or thrown off these gears lubricates the

mainshaft gears, bearings and bushes.

A10

To drain the gearbox, take out the nylon filler plug

and dipstick on toP of the gearbox then unscrew

and take out the plug underneath, draining the oil

into a suitable recePtacle'

After draining, replace the drain plug, making sure

that the rubber "O" ring is in good condition.

Now fill the gearbox with fresh oil and check the

level with the dipstick Provided.

Recommended grades of oil are quoted in Section

A2, capacities on PaSe GD5 and checking frequency

in Section A1 .

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LUBRICATION

SECTION AI4

PRI MARY DRIVE

Like the gearbox, the primary chaincase, having its

own lubricant, is independent of the engine but rhe

level of oil must be checked periodically and the oil

drained and replaced as indicated in the routine

maintenance sheet, Section 41 .

A drip feed is also provided for the rear chain

through an oil well and nozzle at the back of the

chai ncase.

Fig. A12. Chaincase plugs and screw positions

A chaincase drain plug is fitted vertically into the

primary chaincase and the level screw is fitted

directly above this. See Fig. 412.

To drain the oil, take out the chain inspection cao

(1) at the top ofthe case and the drain screw.

Cap (2) is only removed to enable clutch ad justments

to be carried out.

After draining, replace the drain screw, take out

Ievel screw and pour oil through the inspection cap

hole until it commences to run out of the level

screw hole. Replace level screw and inspection cap.

The machine should be upright and on level ground

when this operation is carried out to ensure correct

level of oil.

Oil containing molybdenum disulphide or graphite

must not be used in the primary chaincase.

When replenishing, use only the grades recom-

mended in Section A2.

SECTION AI5

REAR CHAIN

The best method of lubrication is to remove the

chain every 2,000 miles, wash thoroughly in paraffin

and allow to drain, then immerse it in melted

grease (melt over a pan of boiling water) and allow

to remain in the grease for approximately 15 m in utes

to ensure good penetration.

When replacing the chain, make sure that the spring

clip of the connecting link has its closed end pointing

in the direction of travel of the chain (i.e., forwards

on the top run).

Note that the T25T has a chain guide incorporared

in the chainguard for the lower chain run.

A11

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LUBRICATION

SECTION AI6

STEERING HEAD

The steering head bearings are packed with grease

on assembly and only require repacking at the

intervals quoted in Section A1 . Removal and re-

placement of the steering is dealt with in Section

E2 in the fork section.

Wipe the grease from the rollers with a clean cloth

and clean the bearing face thoroughly. Examine the

rollers and the bearing face for Pitting, corrosion or

cracks and renew if necessary. Check that the grease

is as quoted in Section A2.

SECTION A17

TELESCOPIC FORK

The oilcontained in the fork legs not only lubricates

the bearing surfaces, but also acts as the damping

medium. Because of the latter function, it is essential

that the amount of oil in each fork leg is exactly the

same quantity and viscositY.

Oil leakage midway up the forks usually indicates

that an oil seal has failed and requires replacement;

this is dealt with in Section E3.

Correct period for changing the oil is every 10,000

miles (16,000 km.) but some owners may not cover

this mileage in a year, in which case it is suggested

The wheel bearings are packed with grease on

assembly and only require repacking at the intervals

given in Section A1 .

The bearing should be removed as quoted in Sections

F2 and F7. After removal, the bearings must be

that the oil be changed every 12 months.

To drain the oil, unscrew the fork caP nuts and the

small drain plugs in the lower ends of the fork sliding

members. Allow the oil to drain out then, whilst

standing astride the machine, apply the front brake

and depress the forks a few times to drain any oil

remaining in the system.

Replace the drain plugs, remove the caP nuts and

pour { pint (190 c.c.) of oil into each fork leg (see

Section A2 for recommended grades of oil).

washed thoroughly in paraffin and, if possible, an

air line should be used to blow out any remaintng

grit or paraffin.

Do not over-lubricate and avoid handling the brake

shoes with greasy hands.

SECTION AI8

WHEEL BEARINGS

A1Z

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LUBRICATION

SECTION AI9

LUBRICATING THE

The control cables can be periodically lubricated at

the exposed joints with a thin grade of oil (see

Section Al).

A more thorough method of lubrication is that of

feeding oil into one end of the cable by means of a

reservoir. For this, the cable can be either discon-

nected at the handlebar end only, or completely

removed.

The disconnected end of the cable should be

threaded through a thin rubber stoPPer and the

CONTROL CABLES

stopper pressed into a suitable narrow-necked can

with a hole in its base. lf the can is then inverted

and the lubricating oil poured into it through the

hole, the oil will trickle down between the outer

and inner cables. lt is bestto leave the cable in this

position overnight to ensure adequate lubrica-

tion.

Note that the clutch cable has an oil nipple situated

in the outer casing of the clutch cable. A Pressure

oil can should be applied until oil escaPes at either

end of the cable.

SECTION A2O

SPEEDOMETER (AND TACHOMETER CABLE WHERE FITTED)

It is necessary to lubricate the cables to Prevent

premature failure of the inner wires' Care is also

necessary to avoid over-zealous greasing which

may result in the lubricant entering the instru-

ment heads. For lubricating, it is only necessary to

unscrew the cable ferrules and withdraw the inner

wires. The grease should be applied sparingly to

the wires and the top 6 in. must not be greased.

A13

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SECTION B

ENGI NE

INDEX

SECTION

DESCRIPTION

81 DECARBONISING

87 CHECKING VALVE CLEARANCES

83 REMOVING CYLINDER BARREL

84 REMOVING THE PISTON

85 PISTON RINGS

86 RE.FITTING CYLINDER BARREL

87 REMOVING THE ENGINE UNIT

88 TRANSMISSION

89 REMOVING PRIMARY CHAINCASE COVER

B1O CLUTCH DISMANTLING

B11 GENERATOR REMOVAL

B17 INSPECTING THE CLUTCH

B13 CLUTCH SHOCK ABSORBER UNIT

814 GEARBOX SPROCKET

815 CLUTCH OPERATION

816 RE-ASSEMBLING THE PRIMARY DRIVE

817 CoNTACT BREAKER AND AUTOMATIC ADVANCE/RETARD UNIT

B18 TIMING COVERS

B19 REMOVING AND REPLACING OIL PUMP

B2O TIMING GEARS AND TAPPETS

821 SEQUENCE OF GEARCHANGING

8?:2 DISMANTLING THE GEARBOX

B23 SPLITTING THE CRANKCASE HALVES

B24 CRANKSHAFT AND BIG END

B25 FLYWHEEL BALANCING

526 RE.FITTING THE CONNECTING ROD

827 RENEWING THE MAIN BEARINGS

828 RE-ASSEMBLING THE CRANKCASE

829 IGNITION TIMING

B3O FITTING A TACHOMETER

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BENGINE

Fig. Bl. Engine exploded.

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ENGINE B

DESCRIPTION

The 250 c.c. overhead valve single cylinder four-

stroke engine is of the unit constructlon type and

incorporates an aluminium alloy cylinder barrel

which has an austenitic iron liner.

The aluminium alloy die-cast piston has one plain

compression ring, one tapered compression ring,

and a scraper ring. The connecting rod is of H-

section Hiduminium alloy.

Four special bolts hold each of the two flywheels to

the one-piece forged cranl<shaft. lncorporated in

the right-hand flywheel is a centrifugal oil sludge

trap, fitted with a screwed plug. The bolt-on con-

necting rod big-end assembly consists of two bear-

ing shell halves, available in three undersizes for use

with reground crankshafts.

The aluminium alloy cylinder head has cast-in, heavy

d uty cast-iron valve seats and removable valve

guides. Housed within the top of the cylinder head

are two valve rocker spindles, carrying the inlet

rocker at the rear and the exhaust rocker at the

front. Each of the valve rocker spindles has an

eccentric cam which provides a means of adjusting

the valve clearances.

The high performance camshaft operates in two

bushes, one of phosphor bronze and the other of

sintered bronze.

Contained within the primary drive case on the left-

hand half of the crankcase are the clutch assembly,

primary chain and the alternator. The alternator

unit consist's. of an encapsulated six-coil stator,

mounted on three studs, and a rotor secured to the

drive-side shaft.

A vertically mounted oil pump of the double gear

type is driven off a wormwheel on the timing side

crankshaft and supplies oil to the big-end assembly,

piston, cylinder walls and the timing gears.

The gearbox, at the rear ofthe right-hand halfofthe

crankcase, and the primary chaincase are indepen-

dent ofthe engine lubrication system and each con-

tain their own lubricant.

Power from the engine is transmitted through the

engine sprocket and duplex primary chain to the

clutch assembly which has a built-in shock absorber.

Here the drive is taken up by the bonded friction

plates and is transmitted through the four-speed

constant-mesh gearbox to the final drive sprocket.

SECTION B I

DECARBONISING

Decarbonising or top overhaul as it is sometimes

called, means the removal of carbon deposits from

the combustion chamber, piston crown, valve heads

and inlet and exhaust ports, and to restore a smooth

finish to these surfaces. Obviously, whilst the upper

portion of the engine is dismantled for this purpose,

opportunity will be taken to examine the valves,

valve seats, springs, guides, etc, for general "wear

and tear", hence the term "top overhaul".

Carbon, produced by combustion taking place in the

engine when running, is not harmful providing it is

not allowed to become excessive and therefore

likely to cause pre-ignition or other symptoms

which may impair performance.

The usual symptoms indicating the need for decar-

bonising, are an increased tendency for the engine

to "pink" (metallic knocking sound when under

load), a general decrease in power and a tendency

for the engine to run hotter than usual. An increase

in petrol consumption may also be apparent.

PREPARING TO DECARBONISE

Perfect cleanliness is essential to ensure success in

any service task, so before starting a job such as this,

make sure that you have a clean bench or working

area on which to operate and room to place parts

as they are removed.

To facilitate removal of the cylinder head for

decarbonising, first take off the petrol tank, as

detailed in Section D.

With the tank removed, the engine torque stay

bracket can be disconnected.

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BENGINE

The right-hand exhaust system is a pr.rsh fit into the

cylinder head. Remove the two fixing bolts situated

at the silencer, loosen the clip securing the silencer

to the exhaust pipe, disconnect the front fixing at

the front engine bolt and then remove the exhaust

pipe from the cylinder head. The pipe may be a tight

fit and may require tapping with a rubber mallet or

sim ilar.

Remove the carburetter from the cylinder head and

tie it bacl< out of the way.

The oil feed pipe to the rocl<er spindles should now

be disconnected and the sparking plug tal<en out.

REMOVING THE CYLINDER HEAD

Set the piston at top dead centre on the compres-

sion strol<e (both valves closed) and take off the six

nuts holding the cylinder head to the barrel.

Leave the rocker box assembly ir position on the

cylinder head, and raise the latter until it clears its

fixing studs. lt will then be necessary to rotate the

cylinder head assembly about the push rods so as to

clear the frame top tube. The rocker box can now

be removed from the cylinder head, thus exposing

the valves and springs.

VALVE ROCKERS

Rocker arms which have been subjected to a great

deal of wear, make the correct valve clearances

difficult to determine. During their manufacture

the pads are case-hardened and no attempt should

be made to grind them smooth. lf wear of this

nature is apparent therefore, replacement parts

should be fitted.

lf the rockers and spindles are dismantled tal<e care

to renew any damaged washers.

REMOV|NG THE VALVE SPRINGS

Using a valve spring compressor, compress each

spring until the split collets can be removed. The

valve springs and top collars can now be lifted from

the valve stems, rinsed in paraffin (Kerosene), then

labelled inlet. or exhaust as the case may be.

The springs may have settled through long use and

they should therefore be checked in accordance

with the dimensions quoted on page GD2.

lf the springs have settled appreciably, or there are

signs of cracking, they should be replaced.

PUSH RODS

Examine the push rod end cups to see if they are

chipped, worn or loose, and checl< that the rods are

not bent by rolling them on a flat surface (i.e., a

piece of plate glass). lf any of these faults are evident

the rod(s) should be renewed. The exhaust push

rod is the shorter and has a red identification mark

on the top cup.

VALVE GUIDES

Check the valves in the guides; there should be no

excessive side-play or evidence of carbon build-up

on that portion of the stem which operates in the

guide. Carbon deposits can be removed by careful

scraping and very light use of fine grade emery cloth.

lf there are signs of scoring on the valve stems,

indicating seizure, both valve and guide should be

renewed.

A valve guide can be pressed out with service tool

No.51 -6063, but the aluminium cylinder head should

first be heated. The new guide can be pressed in

with the same tool whilst the head is still warm.

Note that the exhaust guide is counterbored at the

end which protrudes into the port.

Whenever new guides have been fitted, each valve

seat must be refaced with a piloted valve seat cutter,

to ensure that the seat is concentric with the guide

bore.

Oversize valve guides are available in 0'002 ins' and

0.01 5 ins.

,i\

ai\

rocker

Fig, 82. Valve assembly

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ENGINE B

VALVES

Valve heads can be refaced on a valve refacer but if

pitting is deep or the valve head is burnt, then a new

valve must be fitted and ground-in.

The valve seats in the cylinder head are unlikely to

require any attention, but if they are marlced, they

should be refaced. Cutting tools are available under

part nurnber Dl 832, D'l 835 and Dl 863. The seat

angle is 45 degrees.

Sometimes when the engine has been decarbonised

many times, valves become "pocketed". This is

when the valve head and seat are below the surface

of the combustion chamber, so impairing the

efficiency of the valve and affecting the gas flow. The

"pocl<et" should be rernoved with a special blending

cutter Dl 835 beferre re-cutting the seat or grinding-

in the valve.

Fig. 83. Pocketed valve

VALVE GRINEING

lf the valve have been renewed or refaced they must

be ground-in to their seats to ensure a good gas-

seal.

This operation is carried out only after all carbon

deposits have been removed from the combustion

cham ber.

Removal ofcarbon from the head, inlet and exhaust

ports can be carried out with scraPers or rotary

files, but whichever method is used great care must

be tal<en to avoid scoring the valve seats or cylinder

h ead.

A final "polish" can be achieved with the use of fine

emery cloth wetted by paraffn.

Do not attempt to decarbonise the cylinder head by

immersing it in caustic soda solution; the solution

has a harmful effect on aluminium.

Having removed all traces of carbon, smear a small

quantity of fine grinding paste over the face of the

valve and return the valve to its seat

Now, using a valve grinding tool, rotate the valve

bacl<wards and forwards, maintaining steady pres-

sure. Every few strokes, raise the valve and turn it

to a new position. A light spring inserted under the

valve head greatly assists in raising the valve to

enable it to be re-posltioned.

Grinding should be continued until the mating

surface of both the valve and seat shovv a uniform

matt finish all round.

htote. Prolonged grinding-in of the valve does nert

produce the same results as re-cutting and must be

avoided at all costs.

REASSEMBL!NG THE EYLINDER FIEAD

Before reassembling the valves and springs, all

traces of grinding paste must be removed from bcth

the valves and their seats.

Smear each valve stem with clean engine oil and

replace the valves in the head.

Fit tlre spring cup, valve springs (with close coils at

the bottorn), and top coliar over each valve stem,

then use a valve spring compressor to allow the split

coilets to be inserted in the top coliar. A little

grease on the valye stem will assist in keeping the

collets in position as the valve springs are released.

Make sure that the collets are correctly seatecl in the

recess on the valve stem.

Refer to "Renroving the valve springs" for inform-

ation on modified collers and collets.

Fig, E'4. Grinding-in valve

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BENGINE

CLEANING TI-{E PISTON CROWN

Unless the condition of the engine indicates that the

piston, piston rings or cylinder bore require atten-

tion, the cylinder barrel should not be disturbed.

lf the barrel is not being removed, bring the piston

to the top ofthe bore and, after plugging the push

rod opening with clean rag, proceed to remove the

carbon fronr the piston crown. A stick of tinsmiths

solder, flattened at one end, provides an ideal

scraper tool and will not damage the alloy piston.

lf possi[:le leave a ring of carbon around the edge of

the piston crown and around the top of the cylinder

bore. This will help to provide an additional seal.

After cleaning the piston crown, rotate the engine

to lower the piston and wipe av,tay any loose carbon

frorn the cylinder wall.

The cylinder barrel and head ;oint faces must also be

cleaned, care being taken not to damage the faces by

scoring with the scraper.

Such score marlcs would result in gas l,ea.kage, loss of

compression or even burning of the cylinder head

face.

RE.FITTING THE CYLINDER HEAD

lnsert the two push rods down the barrel aperture,

on to their respective tappets, the outer one

operating the inlet push rod (see Fig. 85).

Place the cylinder head gasket in position and refit

the head, complete w'ith rocker box.

The push rod inspection cover should be removed

so that the upper ends of the rods can be fitted to

their appropriate rocker arms. Note that the top of

the exhaust push rod is painted red for identification

purposes, and is the shorter.

ln order to avoid any undue strain on the head or

rocker box from valve spring pressure, the piston

should be set at top dead centre on the compression

stroke.

Now, using a suitable torque wrench, tighten the

six cylinder head fixing nuts firmly and evenly to the

figures quoted on page GD5. Check that the push

rods are correctly located in their proper positions

and tighten the rocker box fixing nuts.

INLET EXH AU ST

ROCKER

OUTER

Fig. 85. Fitting the pushrods

Check the valve clearances as described below and

replace the sparking plug.

Proceed by fitting the carburetter, together with its

sealing washers and tighten the fixing nuts to a

torque wrench setting of 10 lb./ft. Reconnect the

rocker oil feed pipe.

Replace the exhaust pipe and secure in position with

the front engine mounting bolt. Refit the silencer.

lf the engine was removed for decarbonising, see

Section 87 for details of replacement.

SECTION 82

CHECKING VALVE CLEARANCES

The clearances between the top of each valve stem

and the rocker arm, must be set when the motor

is quite cold, the clearance being 0.008 in. (inlet)

and 0.010 in. (exhaust).

Remove the rocker caps and take out the spark

plug, to enable the engine to be rotated easily by

hand.

Rotate the engine forward until the inlet valve has

just closed i.e. the pushrod is just free to rotate.

This is the correct position for checking or adjusting

the exhaust valve clearance using a feeler gauge.

When the exhaust valve clearance has been set,

rotate the engine forward again until the clearance

is taken up i.e. just before the valve starts to open.

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ENGINE B

This is the correct position for checl<ing or adjusting

the inlet valve clearance.

These motors have an eccentric cam on each rocker

Fig. 86. Checking valve clearances

spindle, the valve clearances being adjusted in the

following manner:-

Remove the cover plate to expose the slotted ends

of the rocker spindles and slacken the locknuts on

the opposite ends ofthe spindles. To ensure correct

positioning of the rocker arms in relation to the

valve stems, rotate the exhaust rocker spindle in a

clockwise direction until the arm just touches the

valve stem and then turn it bacl< sufficiently to gain

the correct clearance with the feeler gauge. The

procedure for setting the inlet valve clearance is

similar except that the inlet spindle must be rotated

onti-clockwise. lf the spindle bottoms on its thread,

turn it back one complete turn and repeat the

proced u re,

Fig. 87. Valve rocker adiustment

When the necessary adjustments have been made,

secure the spindles with their nuts and re-check

the clearances.

Finally, replace the cover plate and gasket and refit

the spark plug.

SECTION 83

REMOVING CYLINDER BARREL

lf the bore is worn it can sometimes be detected by

placing the fingers on top of the piston and attempt-

ing to push the piston backwards and forwards in

the direction of flywheel rotation. Symptoms

indicating faulty piston rings might include heavy

oil consumption and poor compression, but only if

the valves are known to be in good order. lf the

valves require attention they are much more likely

to be the cause of such symptoms.

Excessive piston slap when warm may indicate a

worn bore or severe damage through seizure.

The cylinder bore can be measured for wear with a

suitable dial gauge, after moving the piston to the

bottom of the bore.

To remove the cylinder barrel, rotate the engine

until the piston is at the bottom of its travel, then

lift the barrel upwards until the piston emerges from

the base of the bore. Steady the piston as it comes

free from the cylinder so that it is not damaged by

violent contact with the crankcase mouth. As soon

as the cylinder has been withdrawn, cover the crank-

case with a clean rag to prevent the entry of foreign

matter.

Examine the cylinder carefully for wear and if a deep

ridge has formed at the top of the bore then the

barrel will require attention.

The barrel will also require attention if there is any

deep scoring as this will cause loss of compression

and excessive oil consumption.

The cylinder barrel is fitted with an austenitic iron

liner, enabling a rebore to be carried out for use

with oversize pistons. The recommended oversizes

are { mm., .020 in. and 1 mm., .040 in.

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BENGINE

SECTION 84

REMOVING

It is not necessary to remove the piston unless it

requires replacement or further dismantling of the

engine is to be carried out.

To remove the piston from its connecting rod, it will

first be necessary to prise out one of the gudgeon

pin circlips using a suitable pointed instrument in

the notch provided.

To remove the gudgeon pin, warm the piston

thoroughly, using a rag which has been soaked in

very hot water and wrung out.

The gudgeon pin can then be pushed out using a

su itable d rift.

Only if the connecting rod is supported very securely

and protected against scratching, can the pin be

removed safely with a suitable drift and hammer.

lf the gudgeon pin comes out easily before the piston

is warm then the pin or piston is worn and will need

replacement.

THE PISTON

After freeing the piston,

piston skirt so that it can

way round.

marl< the inside of the

be replaced the correct

Fig. B8. Removing circlip

SECTION 85

PISTON

The outside face of each piston ring should possess a

smooth metallic surface and any signs of discoloura-

tion means that the rings are in need of replacement.

The rings should also retain a certain amount of

"spri ngi ness" so that when released from the barrel,

the end of each ring lie at least 1| in. apart.

Each ring should be free in its groove but with

minimum side clearance. lf the rings tend to stick

in the grooves, remove them and clean out all the

carbon from the groove and the inside face of the

ring. Care is necessary to permit only a minimum

amount of movement when removing the rings as

they are very brittle and can be broken easily.

RINGS

A piece of a broken piston ring, ground as a chisel,

will provide a useful tool for removing carbon

deposits from the ring grooves.

To checl< the piston ring gaps, place each ring in the

least worn part of the cylinder bore (usually at the

bottom) and locate it with the top of the piston to

ensure it is square in the bore.

Measure the gap between the ends of the ring with

a feeler gauge. The correct gap when new is between

.009/.013 in. and although an increase of a few

thousandths of an inch is permissible, any large

increase to, say.025 in. indicates the need for a

replacement ring.

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ENGINE B

It is advisable to check the gap ofa new ring before

fitting, and ifthe gap is less than 0'009 in. the ends of

the ring must be carefully filed to the correct limit.

The top compression ring is of plain section and

must always be used at the top. The second com-

pression ring has a taper outside face and its uPPer

surface is marl<ed "top" to ensure correct fitting.

lf the ring is fitted upside down, oilconsumption will

become excessive.

The slipper will be displaced as the piston enters the

bore.

Take off the slipper and remove the hardwood

supports, allowing the barrel to drop on to the

cran kcase.

Fig. 89. Checking ring grooves

SECTION 86

REFITTING CYLINDER BARREL

Scrupulous cleanliness must be observed when

reassembling, and each component should be

smeared with fresh oil before replacing.

Warm the piston before inserting the gudgeon pin

and ensure that the piston is the correct way round

before fitting. Always use new gudgeon pin circlips

and see they are pressed well down into their

grooves.

lf the circlips should come adrift or if one is omitted,

the cylinder barrel will be damaged and may require

replacement.

Note that the studs on each side of the push rod

tunnel have the greater thread length into the

cylinder barrel.

Use a new cylinder base washer and support the

piston with two pieces of hardwood placed across

the crankcase, under the piston skirt.

The piston ring gaps must always be egually spaced

round the piston that is, at 120'apart to restrict gas

leal<age through the gaps to the minimum.

Using the piston ring slipper service tool No. 61 -

6031 compress the rings so that they are just free to

move and replace the barrel. Fig. Bll. Replacing cylinder barrel

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BENGINE

SECTION 87

REMOVING THE

During the process of removing the engine unit,

keep careful watch for any nuts or bolts which are

found to be loose or have worn considerably.

ENGINE UNIT

On removal of the flange fixing nuts, the car-

buretter can be withdrawn from its studs and

tied up out of the way.

Such parts are no longer safe and must be replaced.

Examine the wiring for places where the insulation

may have rubbed through and protect with a few

turns of good insulating tape. The owner should

bear in mind that a bare wire can cause an electrical

short-circuit which may set the machine on fire.

(f) Detach the engine head steady bracket.

(g) Remove the chainguard (see Section D2), un-

couple the rear chain at its spring link and

detach it from the gearbox sprocl<et. Finally,

disconnect the clutch cable from the operating

lever on top of the timing cover.

(h) Remove the crankcase undershield which is

retained by two nuts at the front and two

location slots at the rear. The (footrest) bolt

will have to be loosened to allow the under-

shield to be removed from the frame. Allow

the right footrest to swing clear.

The engine/gearbox unit is mounted in the frame at

three points. At the rear the attachment is by two

triangular plates attached to the frame tube, the

engine being held by two bolts and nuts. A second

fixing point is located below the crankcase, com-

prising one long bolt through the crankcase and

frame lugs. The third attachment point is at the

f rame front down tube.

Procedure for removal of

follows:-

(a) First, remove the petrol

the engine unit is as

tank. See Section D15.

(b) Release the exhaust pipe from the front engine

mounting, remove the silencer. The exhaust

pipe is a push-fit into the cylinder head port and

can now be withdrawn from the front.

Section ,\4 then uncouple the rocker oil feed

pipe and the supply and scavenge pipes beneath

the crankcase.

(d) Disconnect the generator, oil pressure switch

and the contact breaker leads from their snap

connectors at the electrical box. Also disconnect

the high-tension lead and take out the sparking

plug to prevent damage.

(e) Loosen the clip securing the air filter connecting

tube to the carburetter and pull a'way from the

carburetter intake.

810

Disengage the engine from

lift out from the right-hand

the frame brackets and

side.

Replacement of the engine unit is a reversal of the

above procedure. Ensure that all nuts, bolts and

electrical connections are securely tightened. Take

care to replace the two spacers correctly on the

right side of the engine. A final check must be made

to ensure that all nuts and bolts are tightened

securely and that the handlebar controls are suitably

re-adjusted.

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ENGINE B

SECTION B8

TRANSMISSION

DESCRIPTION

Power from the engine is transmitted through the

engine sprocket and primary drive chain to the

clutch chainwheel, then via the clutch driving and

driven plates to the shock absorber unit and gear-

box mainshaft.

The d rive is then transmitted th rough the fou r-speed

gearbox to the final drive sprocket and finally, to

the rear wheel.

The clutch, when operated correctly, enables the

rider to stop and start his machine smoothly

without stalling the engine, and assists in

REMOVING PRIMARY

The primary chaincase cover is held in place by ten

Phillips-head screws. (See Fig. A12 for position of

screws).

The drain plug is fitted vertically into the bottom

of the chaincase. (See Fig. A12).

The oil level plug is located immediately above the

drain plug. (See Fig. 412(E)).

providing a silent and effortless gearchange.

Thus it will be evident that the satisfactory opera-

tion of one part of the transmission system is

dependent on another part. ln other words, if one

part is worn or faulty, it can very often prevent

other parts from working properly.

The dismantling and reassembly of the primary

drive can if necessary, be carried out with the

engine unit in the frame, but will be treated in the

following notes, as though the unit were on a

work bench.

SECTION 89

CHAINCASE COVER

Drain the oil as described in Section A14 and take

out the fixing screws. The screws are of three

different lengths and careful note should be taken of

their respective positions to facilitate refitting. lf

the joint has not already been broken, tap the cover

gently with a hide mallet to release, but have a suit-

able receptacle underneath to catch any remaining

oil.

SECTION B IO

CLUTCH DISMANTLING

Remove the four spring retaining nuts (P) Fig. 81 6,

and withdraw the springs with their cups. The

pressure plate and the remaining clutch plates can

then be taken out. lf these are the only items

requiring attention, the clutch need not be dis-

mantled further.

Before unscrewing the clutch centre nut, it will be

necessary to lock the chainwheel and centre to-

gether with clutch locking tool 61-3774 and to insert

a bar through the connecting rod small-end eye. lf

a service tool is not available, engage top gear and

lock the gearbox sprocket with a length of chain in

a vice. Flatten the tab washer under the clutch

centre nut and unscrew the nut, which has a normal

right-hand thread.

Take offthe nut, tab washer and distance piece. The

clutch push rod may now be withdrawn but do not

attempt to remove thechainwheel at thisstage. The

generator must be removed as in Section 811 before

the chainwheel is disturbed.

Note. Alternatively, the clutch sprocl<et may be

removed by prising out the twenty five roller

bearings and allowing the sprocket to move both

outwards and forwards until it can be unmeshed

from the primary chain. This alternative only

applies if the shock absorber assembly can readily

be detached from the hub to allow access to the

rol I ers.

811

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BENGINE

SECTION BII

GENERATOR REMOVAL

The generator comprises the rotor, fitted to the

engine shaft, and the stator which is mounted on

three studs around the rotor, both being detailed in

Section G1.

Before the clutch chainwheel, chain or engine

sprocket can be removed, the generator must be

taken off.

To remove the stator, take off the three nuts and

pull the generator lead through the rubber grom-

met in the front ofthe chaincase. Take care not to

damage the stator casing, when pulling the stator off

its studs. Note that the stator unit is fitted with the

lead on the inside.

I NSPECTI NG

The four driving plates have segmenrs of special

friction material which are securely bonded to the

metal. These segments should all be complete, un-

broken and not displaced. Even if there is no ap-

parent wear or damage to the plates or segments,

the overall thickness of each segment should be

measured and if the extent of wear is more than

030 in. (75 mm.), the plates should be replaced.

Standard thickness is .167 in. (4.242 mm.).

The tags on the outer edge ofthe plates should be a

reasonable fit in the chainwheel slots and should not

be burred. lf there are burrs on the tags or the seg-

ments are damaged, the plates should be renewed.

The plain driven plates should be free from score

marks and perfectly flat. To check the latter, lay the

plate on a piece of plate glass; if it can be rocked

from side to side, it is buckled and should be re-

placed.

Check the chainwheel for wear; if the slots are

corrugated or the teeth are hooked and thin, the

chainwheel should be replaced.

812

THE CLUTCH

Check the chainwheel roller bearing for up and

down movement. Slight play is permissible but

if excessive, the bearings should be renewed.

Fig. Bl2. Removing clutch

The primary chain tensioner can

but note that the small spacer is

stud.

now be taken off

fitted on the rear

Bend back the tab of the loclcwasher under the

engine shaft nut and unscrew the nut (right-hand

thread). Pull off the rotor and take out the small

Woodruff key from the shaft to avoid losing it.

Using extractor tool 61-3583, the clutch sleeve can

now be freed from the tapered mainshaft, enabling

the clutch chainwheel, chain and engine sprocket to

be withdrawn together.

SECTION BI2

iS,

":{ ,

r ri-:

fu.,. ..di*:;

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ENGINE B

Fig. Bl3. Clutch exploded

When refitting the shock absorber rubbers it may

be found necessary to use a lubricant, in which case

a liquid soap is recommended.

Do not use oil or Srease.

SECTION B 13

CLUTCH SHOCK ABSORBER UNIT

To inspect the shock absorber rubbers which are

within the clutch centre, take out the four counter-

sunk head screws adjacent to the clutch spring

housings and prise off the retaining Plate.

The rubbers should be quite firm and sound, and

should not be disturbed unless wear or damage is

sus pected.

SECTION B 14

GEARBOX SPROCKET

Access to the gearbox sprocket can only be obtained

when the clutch assembly has been removed'

Take out the six screws holding the circular plate

at the back of the primary case, break the joint and

remove the plate with its oil seal. (See Fig. 814).

Look for signs of oil lealcage down the back of the

cover. lf leakage is evident, change the oil seal,

taking care to see that it is fitted the correct way

round with the lip of the seal to the inside of the

primary case.

A felt washer is fitted between the circular plate and

the sprocket fixing nut, preventing the entry ofgrit

which may damage the small oil seal. lf the washer

no longer appears serviceable, replace it. Fig. 814. Gearbox sprocket cover

813

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BENGINE

lf it is necessary to change or renew the gearbox

sprocket, first place a length of chain round the

sprocket and lock in a vice or with a suitable bolt,

then flatten the tab washer and unscrew the large

nut. The sprocket can now be pulled offthe main-

shaft splines.

lfthe oil seal is suspected of being faulty or leakage

has occurred it should be renewed. Check that the

sprocket boss is not worn or damaged as this would

quickly damage a new seal.

lf the sprocket boss is smooth and not scored it can

be replaced, but lightly oil the boss to avoid damag-

ing the seal as the sprocket is pressed home.

Reassemble in the reverse order but do not omit to

turn the tab washer over the nut after tightening.

SECTION B 15

CLUTCH OPERATION

As already indicated, the clutch, being part of the

transmission system, carries power to the rear

wheel, but by separating the driving and driven

plates this connection is broken.

The disengagement is achieved by operating the

clutch lever, the force imposed being transmitted

via the clutch cable to the clutch lever in the timing

case. The lever, working on the rack-and-pinion

principle, drives the push rod through the hollow

gearbox mainshaft, forcing the pressure plate out;

so compressing the clutch springs and freeing the

plates.

To ensure smooth clutch operation, it is essential

that the spring pressures are equal and that the

pressure plate runs "true".

See Section 816 for details of clutch adjust-

ments.

SECTION B 16

REASSEMBLING THE PRIMARY DRIVE

Place the felt grit protection washer in position

against the sprocket securing nut and replace the

circular cover, using a new paper gasket jointed on

one side only.

lfthe clutch hub has been removed from thechain-

wheel, smear the sleeve with grease and place the

25 rollers in position. Now, slide the chainwheel

over the rollers and fit the clutch centre over the

splines of the sleeve.

Pass the stator lead th rough the front of the pri mary

chaincase and clip in position behind the cylinder

base. This operation may be found difficult if left to

a later stage.

The engine shaft distance piece should not have been

disturbed, but if it was removed for any reason, it

814

must now be refitted with the chamfered side out-

wards.

Fig. Bl5. Fitting primary drive

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ENGINE B

See that the Woodruff key is fitted to the gearbox

mainshaft and it is a good fit in the keyway.

Place the primary chain around both the engine and

clutch sprockets, pulling the chain taut.

Pick up the engine sprocket, chain and chainwheel

with both hands and slide the sprockets on to their

respective shafts. lt will be necessary to turn the

clutch chainwheel to locate over the keyed shaft.

Place the thick washer with the recess outwards in

position against the clutch hub then the tab

washer and fixing nut. After tightening the nut,

to the torque setting in General Data lock in

position with the tab washer.

Replace the clutch plates, starting with one plain

then one segmented plate and so on alternately,

there being five plain plates and four segmented

plates. lnsert the clutch push rod into the hollow

mainshaft.

Place the pressure plate in position and fit the four

spring cups with springs, which should be of equal

length. lf in any doubt about the condition of the

springs, replace the m since they are q u ite inexpe nsive.

Screw on the four spring nuts (P) Fig. 816, with a

slotted screwdriver until the first coil ofeach spring

is just proud of its cup.

lf the springs are compressed excessively, the

handlebar lever will be stiff to oPerate. On the

other hand, ifthe spring Pressure is insufficient the

clutch will tend to slip. Check the accuracy of the

spring setting by declutching and depressing the

kickstart lever, when it will be seen if the pressure

plate is runnning "true" or not. lf necessary, adiust

each nut accordingly to correct any "run-out".

When the spring setting has been determined the

clutch movement can be adjusted by means of the

central screw and locknut on the pressure plate.

The clutch operating rod should have 1f in. (1 '5

mm.) clearance between the clutch operating

mechanism and the pressure plate. To achieve

this remove the inspection cap from the centre of

the primary cover with the clutch cable either dis-

connected or the handlebar adjustment slackened

right off.

Unscrew the hexagonal lock nut and screw in the

slotted adjuster screw in the centre of the pressure

plate until the pressure plate just begins to lift.

Unscrew the adjuster one full turn and secure it in

that position by re-tightening the lock-nut. The

clutch operating cable should then be re-adjusted

by means of the handlebar adjuster until there is

approximately { in. (3 mm.) free movement in the

cable.

Fit the key to the crankshaft and replace the rotor

on to the keyed engine shaft with its "Lucas"

marked face outwards and fit the tab washer and

nut, to the torque recommended in 'General Data'

GD5.

Turn the tab over the nut after tightening securely.

Replace the primary chain tensioner on to the lower

stator studs (E), Fig. 816, and fit the small sPacer on

to the rear stud.

Fit the stator on to its studs with the cable on the

inside, at the front, and secure with the self-locking

nuts. Adjust the primary chain tensioner to give

approximately f in. free play on the top run of the

chain between the sprockets.

Having completed the assembly of the primary drive,

the primary cover can now be replaced. Apply

jointing cement to both faces of the chaincase and,

using a new gasket, replace the cover. Ensure that

the fixing screws are fitted in their correct posi-

tions (see Fig. A12).

See that the oil level and drain screws are correctly

located in the lower edge of the case and refill the

case with oil as in Section A14.

Fig, 816. Chain and Pressure plate adiustment

815

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BENGINE

SECTION BI7

CONTACT BREAKER AND AUTOMATIC ADVANCE AND

RETARD UNIT

The contact breaker assembly is located behind the

chromium plated circular cover on the right hand

side of the engine. Access to the contact breaker

assembly is gained by removing the chnomium cover

which is held by two screws.

The assembly comprises the contact breaker plate,

on which are mounted the contacts. An oil seal is

fitted in the back of the housing and prevents oil

from reaching the assembly. The automatic advance/

retard unit, mounted behind the plate, consists of

two spring-loaded bob-weights coupled to the con-

tact breaker cam and is secured by one central bolt

and washer.

The bob-weights, when the engine is stationary,

retain the contact breaker cam in the fully retarded

position.

Pillar bolt

Secondary bracket screws

Contact adiusting screws

Eccentric screws

Secondary bracket screws

Eccentric screws

Pillar bolt

Fig. B17. Contact breaker unit

Central

Securing Bolt

Fig. 818. Automatic advance and retard unit

816

As the engine revolutions increase, centrifugal force

carries the bob-weights outwards progressively

turning the cam into the direction of rotation, thus

advancing the ignition.

The elongated holes in the contact plate enable the

plate to be moved backwards and forwards around

the cam, so providing a means of fine adjustment for

ignition timing.

REMOVING THE AUTOMATIC

ADVANCE AND RETARD UNIT

Disconnect the contact breaker lead at its snap con-

nector, unscrew the two pillar bolts and take offthe

plate complete with contacts and cable.

To remove the auto-advance unit and cam, first take

out the central fixing bolt then free the unit from its

taper with service tool 61 -3816.

Avoid removing the auto-advance unit unnecessarily

as the timing will have to be reset. During re-

assembly refit loosely and retime the ignition as

detailed in Section B29.

CONTACT BREAKER POINTS

To remove the contact points, remove the nut,

nylon insulating sleeve and contact breaker lead.

This releases the moving contact with the nylon heel

which can then be lifted clear of the steel pivot. The

contact adjusting screw (see Fig. 817) should be

removed and the fixed point lifted clear of the

secondary backplate.

When replacing, do not omit to fit the fibre washer

between the moving point spring and fixed point

plate.

It will now be necessaryto reset the contact points

gap after replacement. Turn the engine until the

nylon heel is on the cam at the scribe marking,

slacken the contact adjusting screw and turn the

eccentric screw until, checking with a feeler gauge

at 0.015 in. (0.381 mm.), the gap is correct. Re-

tighten the contact adjusting screw.

25w 29

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ENGINE B

It is advisable to check the ignition timing after

carrying out any adlustment to the contact breaker

points as a variation in the contact points gap tends

to alter the timing. Widening the points gap ad-

vances the ignition; closing the gap retards the

ignition. Although this variation is very slight, it

must be remembered that accurate timing is im-

po rtant.

See Section B29 for full details of ignition timing.

SECTION B 18

TIMING COVERS

To obtain access to the timing Sears or the gearbox

components it will be necessary to remove the

covers on the right side of the engine. lt will be

assumed that the primary drive has been dismantled

as described on previous pages.

To remove the outer cover, first take off the gear-

change and kickstart pedals, then take out the ten

cover retaining screws, noting their respective

locations as shown in Fig. 819. The cover, complete

with contact breal<er plate and clutch operating

mechanism, can now be withdrawn, exposing the

auto-advance unit and kick-start mechanism. Note

that the contact breaker lead is held by a spring clip

under one of the inner timing cover screws.

lf the clutch operating lever is to be removed, care

must be taken to avoid losing the operating rack and

ball which are loosely located on the inside of the

outer cover. When reassembling the mechanism

ensure that the operating lever is parallel with the

joint face of the cover whilst the operating rack is

flush with the end of its housing.

It is not necessary to remove the kickstart quadrant

or spring unless they reguire attention.

lf necessary free the spring from the kickstart

spindle and withdraw the quadrant comPlete with

layshaft needle bearing. When fitting a new spring,

first locate the hooked end of the spring in the

quadrant slot then "wind-up" the spring in a clock-

wise direction and slip the eye of the spring on to its

stud. The quadrant bush is a push-fit into the outer

timing cover.

Remove the contact breaker auto-advance unit as

described in Section B'l 7.

1ti,"

(Retaining C.B.Wire Hook)

Kickstart Spring

Anchor Bolt

Fig. B20. Location of inner cover retaining screws

To remove the inner timing cover take out the

seven fixing screws (see Fig. B20). Note that the

contact breaker cable clip fits under the uppermost

central fixing screw. Also unscrew the kickstart

spring anchor bolt. The inner cover joint can

be broken by tapping gently around the edges with

a mallet.

Fig.819. Location of outer cover retaining screws

817

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BENGINE

The cover, complete with kickstart ratchet, gear

cluster and gearchange assembly can now be eased

away, leaving the oil pump and timing gears exposed.

Do not lose the loose fitting thrust washer on the

end of the layshaft.

Note that the camshaft bush in the cover is located

by a small peg to ensure correct alignment of the oil

holes during reassembly. Check that the oil seals in

the covers are not damaged and are fit for further

use.

Note that the contact breaker oil seal should be

fitted with the lip inwards. Use the contact breaker

oil seal protector part number 7168 when replacing

the inner cover. Refer to Figs. B19 and 20 for

location of screws.

Use a suitable bar through the small end eye to

lock the flywheel, flatten the tab washer under the

crankshaft nut and unscrew the nut which has a

normal right-hand thread.

Pull off the crankshaft pinion, using extractor

No. 61-3808 with appropriate legs. The oil pump

worm-drive need not be disturbed unless further

engine dismantling is to be carried out, in which

case the extractor should be used with the special

legs.

Unscrew the three self-locking nuts from the main

body of the pump and pull the pump off its studs.

SECTION B 19

It is not advisable to dismantle the oil pump unless

it is suspected that there is possible damage caused

by neglected oil changes.

Full details of dismantling and rebuilding the oil

pump are given in Section A1 1.

Ensure that the joint faces are clean, apply a smear

of grease to a new gasket and place the gasket in

position on the crankcase face. Ensure that the

gasket is not fitted back to front as this will cause

a blockage. Locate the pump over the studs and

replace the fixing nuts. Tighten evenly to a torque

of5to7lb.lft.

i/ c''

REMOVING AND REPLACING OIL PUMP

,.9-1',,

(

cl' )

(

Fig, 821. Removing inner timing cover

818

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ENGINE B

SECTION B2O

TIMING GEARS AND TAPPETS

the feet, they should

must also be examined

be replaced. The camshaft

as this may also be worn.

Fig. 823. Timing marks

Removal of the crankshaft pinion and

wormdrive is described in Section 81 9.

Pull the camshaft, with pinion, from the

and let the tappets fall clear. The pinion

fit on the end of the camshaft.

Fig.B.24. Correct fitting of tappets

Note that one end ofeach tappet foot has been made

slightly thinner than the other. When refitting, it is

most important that this end faces towards the front,

as indicated in Fig. 824. Ensure that the cam

followers are fitted before the camshaft.

Reassembly of the timing gear is the reversal of the

dismantling procedure. Care must be taken to

match the timing marks on the pinions.

oil pump

cran kcase

is a push-

Examine both ends of each tappet for signs of wear

or chipping and make sure that they move freely in

the crankcase. lf there are signs of "scuffing" on

:1i

SECTION B2I

SEAUENCE OF GEARCHANGING

The gearbox is operated by the pedal on the right

side of the engine. The pedal is splined onto the

quadrant which houses two spring loaded plungers.

The plungers locate in "windows" in the camplate,

and operate in such a manner that as the pedal is

moved the camplate is relocated in the required

position. This position is ascertained by a spring

plate which locates in one of five notches on the end

of the camplate. The arrangement of the selector

mechanism is shown in Fig. B25. Two selector forks

locate in tracks in the camplate and onto a sliding

gear on each gear shaft.

819

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BENGINE

Fig. B25. Gearchange mechanism

Fig. 827 shows the camplate being held in the neutral

position, i.e. the second notch. When first gear is

selected by depressing the gearbox pedal, the lower

quadrant plunger locates into a camplate window

and lifts the camplate. The spring plate is ejected

from the neutral notch and comes to rest in the

first gear notch. During this movement the lay-

shaft selector fork is relocated, which in turn

causes the layshaft sliding gear to mesh with the

layshaft first gear as shown in Fig. 826.

When the gear has been selected the quadrant

returns to its original position. This allows the

upper quadrant plunger to locate in the second

window in readiness to move the camplate to the

second gear position.

As the pedal is lifted to select second gear, the

camplate moves downwards moving the layshaft

selector fork to mesh the layshaft sliding gear

with the second gear. The camplate is again located

by the spring plate at this stage in the third notch

as shown in Fig. B28. From the diagram it can be

seen that the quadrant plungers are in a position

to select third gear or return to either neutral or

fi rst gear.

When the camplate is moved to the third gear

position, both selector forks are moved as shown

in Fig. B29. The layshaft sliding gear is returned

to its neutral position, i.e. not in mesh with either

low or second gear, but the mainshaft sliding gear

is meshed with the mainshaft third gear. Again

the quadrant plungers are able to move the camplate

eithr:r way.

Finally the selection of fourth (top) gear operates

the mainshaft selector fork only and moves the

mainshaft sliding gear into mesh with the high gear

as shown in Fig. 830. This gear carries the gearbox

s p rocket.

On each illustration the transmission of d rive

through the shafts and gears is represented by a red

line.

SELECTOR AND

CAMPLATE IN FIRST

GEAR POSITION

820

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ENGINE B

SELECTOR AND

CAMPLATE IN

NEUTRAL POSITION

Fig. B.27. Neutral selected

SELECTOR AND

CAMPLATE IN SECOND

GEAR POSITION

Fig. B28. Second gear selected

821

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BENGINE

SELECTOR AND

CAMPLATE IN THIRD

GEAR POSITION

Fig.B.29. Third gear selected

SELECTOR .AND

CAMPLATE IN FOURTH

GEAR POSITION

BZ7

Fig. B30. Fourth (top) gear selected

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ENGINE B

SECTION B.22

DISMANTLING

GEARCHANGE MECHANISM

First remove the timing covers, as detailed in Section

81 8.

Press in the cam plate plungers and withdraw the

gearchange quadrant complete with spring"

The spring-loaded plungers are retained by a small

plate, secured with one screw,

The gearchange return spring pivot bolt need not be

d istu rbed.

Fig. B3l. Gearchange mechanism

Take out the large split pin from the outside of the

cover and withdraw the camplate Pivot Pin. This

job will be simplified if a suitable bolt is screwed

into the pin enabling the pin to be extracted with

pliers (see Fig. B32).

6"""

THE GEARBOX

The camplate can now be withdrawn from its slot,

complete with selector forks and spindle, the lay-

shaft with fixed top gear, second gear and sliding

gear (third), and the mainshaft sliding gear (second).

The large layshaft low gear with its bronze bush can

now be removed. Note that the toP face ofthe cam

plate is stamped with "69" (see Fig. B34) to ensure

correct reassembly.

Check the cam plate for wear in the cam tracks and

the plunger "windows".

Also check that the quadrant plungers are not

chipped or worn and are quite free in their housings.

The cam plate locating spring plates are secured to

the gear-side crankcase half with two small bolts. lf

they are damaged or no longer retain their tensions,

then they must be replaced.

Proceed as detailed above, when it will be seen that

only the mainshaft with its third and low gear,

remains on the inner timing cover.

To remove the mainshaft, grip it in a vice using soft

metal clamps, unscrew the kickstart ratchet nut

then take off the special washer, spring, ratchet

pinion, sleeve and driving pinion. The gearbox

mainshaft can now be withdrawn from the cover

bearing, together with its low gear and third gear.

@!ss @@a

\.: 25ws

Fig. B33. Kickstart ratchet

The low gear is a press-fit on to the shaft, and

retains the larger gear which has a spacer between

itselfand the end ofthe splines.

lf it is necessary to change either of these gears, the

shaft must be pressed out of both gears at the same

time, an operation which requires a good press

properly mounted on a workbench.

Fig. 832. Removing the cam plate pivot pin

823

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BENGINE

The layshaft second gear is held against the fixed

gear (high) by a circlip.

When examining the gears, look for cracked,

chipped or scuffed teeth rhe latter will show (if

present) on the thrust faces ofthe teeth.

GEARBOX BEARINGS

When examining the gearbox bearings and bushes

for wear, do not overlool< the bronze bushes in the

layshaft low gear and the mainshaft high gear. The

mainshaft high gear is still in the crankcase at this

stage.

The layshaft has needle roller bearings at each end,

one in the crankcase and one in the kickstart quad-

rant boss.

The mainshaft has two ball journal bearings, one at

each end. To gain access to the left-hand bearing,

first remove the gearbox sprocket (as detailed in

Section Bl 4), then drive the high gear sleeve pinion

through into the gearbox.

After prising out the oil seal, the bearing can be

pressed out from the inside ofthe cover.

Note. Before attempting to remove any bearing or

bush from an aluminium case, the case should first

be heated. The bearing can then be pressed out and

the replacement fitted whilst the case is still hot.

The right-hand mainshaft bearing can be pressed out

from the inside ofthe inner cover, after first remov-

ing the circlip.

GEARBOX REASSEMBLY

Before reassembly, note that if there has been any

previous tendency to jump out of second or third

gear, the following parts should be fitted as a set:

Part No. Description

T3850 Cam plate

T3854 M/S Selector Fork

ld entification

Stamped 69

Has ..fin. DlA.

BOSS

The index spring then pushes the selected fork out

of engagement and the gearbox finds the neutral

position between third and top gear. To eliminate

the problem, slacken both spring retaining bolts

and move the spring away from the mainshaft.

Retighten the bolts.

It will be assumed that all bearings, bushes and oil

seals have been replaced as necessary.

If it has been removed, replace the cam plate, correct

way round in the cover slot (see Fig. B34 for

Fig. B34. Showing camplate marking.

guidance), insert the pivot pin and secure with the

split pin.

lnsert the mainshaft fitted with its low gear and

third gear, into the cover bearing, replace the kicl<-

start ratchet assemblyand secure with the fixing nut.

It will be necessary to hold the mainshaft in a vice,

using soft nretal clamps, to righten the nut fully.

Holding the cover face down, place the layshaft low

gear with its shim (C) Fig. B35, and sliding gear

(third) in position on the cover. Fit its selector forl<,

the roller being located in the lower cam plate track.

Next fit the mainshaft sliding gear (second) with the

appropriate spacers. Replace its selector fork and

locate the fork roller in the upper cam track. lnsert

the spindle through the selector fork bosses and

locate in the cover.

T3876

T3877

M/S Second Gear Stamped 57

Li S Third Gear Stamped 57

Any tendency for the gearbox to jump out of top

gear is often caused by the camplate index spring

plate being badly positioned. lf it has been slackened,

the spring often moves towards the mainshaft thus

allowing the selector fork to compress it when

selecting top qear.

874

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ENGINE B

LAYSHAFT I

dffis

Fig. B35. Gear cluster exploded

The layshaft, with its remaining two gears (fixed

high gear and second gear) can now be passed

through the gears on the cover, into the kickstart

boss needle roller.

Fit the gearchange return spring to the quadrant

and replace the assembly in the cover, locating the

spring loop over the pivot bolt. lt will be necessary,

whilst carrying out this operation, to press in the

plungers with a suitable flat-bladed instrument,

before finally engaging the plungers with the cam

plate "windows" as the quadrant pressed home.

A thrust washer (D) is fitted to the driveside end of

the layshaft when there should be just perceptible

end float" The mainshaft, being locked to the inner

cover, does not need checking for end float but

excessive movement between the gears and the ends

ofthe splines must be corrected by fitting the appro-

priate spacers. See Fig. B35 for position of each

spacer, the thiclcnesses and part numbers of which

are as follows:-

.093 I .094 i n. (T2678) ;

.098/.099 in. (12679);

.103 I .104 in. (T2680).

.0701.071in. (T2665);

.07s 1.076 in. (T2664)

.080/.081 in. (T2666).

Standard shim (T2670).

.078/.080 in. (T2672);

.083/.08s in. ([2671)

Fig. B35. Fitting the gearchange quadrant

B2s

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BENGINE

SECTION 823

SPLITTING THE CRANKCASE HALVES

Before attempting to part the crankcase halves, first

remove the primary drive assembly, timing covers

and timing gear as described on previous pages.

Working on the primary side of the crankcase, first

remove the three bolts at the lower front of the

case then take offthe four stud nuts; two from the

centre of the case and two from the cylinder

base.

Fig. 837. Removing a Woodruff key

CRAN KSHAFT

Removal ofthe connecting rod from the crankshaft

is quite straightforward but, to assist in correct re-

assembly, it is recommended that the rod and its

cap are marked to ensure replacement in the same

position. Using a suitable tube spanner, unscrew

the cap retaining nuts alternately a turn at a time to

avoid distortion, then withdraw the cap and con-

necting rod.

When extractinS the bearing shells, note that they

are each located by means of a small tag.

lf the shells appear to have worn considerably or are

badly scored, then it will be necessary to regrind

s26

Fig. 838. Splitting the crankcase using Service Tool

2165

The sump filter and the oil pipe union may be left on

the crankcase unless they require cleaning or re-

placement.

Remove any Woodruff keys which may still be in the

shafts, noting their particular locations.

Remove the hollow dowel from the upper right of

the timing side joint face and position service tool

as shown above (Fig. 61-6045).

SECTION B'24

AND BIG.END

the crankshaft journal for use with undersize shells,

as indicated in the chart overleaf.

Note. Replacement bearing shells are prefinished

to give the correct diametrical clearance on a suit-

ably reground journal. On no account should the

shells be scraped or the connecting rod and cap

joint faces be filed.

Before regrinding, remove the flywheels. Four

special bolts, of two different sizes, secure each

flywheel to the crankshaft webs. Note that the

right-hand flywheel contains an oil sludge trap and

is fitted with a screwed plug. Degrease the threads

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ENGINE B

ofthe bolts and the mating surfaces ofthe cranl< and

flywheel with cellulose (lacquer) thinners and apply

"Loctite" to these areas prior to reassembly. lf at

all possible, warm the whole assembly to approx-

imately 300'F. to set the "Loctite". This will

prevent effectively any loss of oil pressure around

the crank.

After regrinding, the appropriate undersize must

be clearly marked on the outer face of each crank-

shaft web. lt is most important that the radii at the

inner faces of the crank journal remain at .070/.080

in.

Fig. B39. Removing a flywheel

Bearing Shell

Marking Suitable Crankshaft Journal Size

Standard 1-4375 in.

1 .4380 in.

36'5125 mm.

36.5252 mm.

First regrind -.010 in. 1-4275 in.

1'4280 in.

36.2585 mm.

36.7717 mm.

Second regrind -.020 in. 1.4175 in.

1 .4180 in.

36.0045 mm.

36.0172 mm.

Third regrind -.030 in. 1.4075 in.

1.4080 in.

35.7505 mm.

35.7632 mm.

SECTION 825

FLYWHEEL BALANCING

lf the flywheels have been removed and refitted, the

assembly should then be re-balanced. Flywheel

balancing is a skilled operation and should not be

undertaken by anyone other than an expert

mechanic having access to the necessary equipment.

A drilling machine with depth stop is required.

Balancing must be carried out on a set of knife edge

rollers, the rollers of which must be set perfectly

horizontal.

To ensure accurate balancing, a weight (part

No. 61-6124) must be attached to the crankshaft

jou rnal.

Place the crankshaft centrally on to the rollers and

revolve a few times. Allow the assembly to come to

rest then mark the lowest point on the flywheels

with chalk. This will indicate the heaviest part of

the assembly.

The next step is to find the amount of out-of-balance

so, plasticine is applied to the rim of each flywheel

diametrically opposite the heaviest point (marked

with chalk), until the assembly remains stationary

when placed in any position on the rollers.

The wheels must now be drilled at the heaviest

point to remove metal equivalent in weight to that

of thr: plasticine.

Drilling should be confined to the thicker portion of

each flywheel, opposite the balance weight, and

BZ7

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BENGINE

must be carried out equally on the periphery of both

wheels. The holes must not be deeper than $ in. or

be more than $ in. in diameter. Obviously, ir is

wiser to start with a smaller diameter hole which

can be opened out if necessary, than to start with a

large hole and find that too much metal has been

removed.

Finally, thoroughly wash the assembly in paraftin

and check that the oil-ways are free from blockage.

CON NECTING ROD

Fig. 840. Fitting a bearing shell

SECTION B.27

MAIN BEAR.I NGS

the roller bearing using service tool No. D3677.

(See Section J, Fig. J17).

Checl< the right side main bearing for excessive

play of the inner race and also inspect for pitting

and roughness ofthe bearing surface. lt is advisable

to renew both the main bearings even if only one of

them displays prominent signs of wear or damage.

To assemble the new bearings first ensure that the

bearing housing is clean and then heat the crankcase

to approximately 1 00'C and then drift in the bearing

on the outer race, using a press where possible.

When the left side bearing is assembled press the oil

seal into position.

SECTION B.26

REFITTING THE

The need for cleanliness cannot be overemphasized

and, as the various parts are assembled, all bearing

surfaces should be coated with clean engine oil and

new self-locking nuts used.

Place the new bearing shells in both the connecting

rod and cap, making sure they are seated correctly.

Fit the rod to the crankshaft journal and replace the

end cap. After checking that the marks on the rod

and cap correspond and that the rod is the right way

round, insert the bolts and tighten the new self-

locking nuts to a torque setting of 25 177 lb.lft.

Using a pressure oil can, force clean oil through the

drilling, at the right-hand end ofthe crankshaft until

it is seen to issue from around the big-end bearing,

thus indicating that the oil-ways are not blocked and

are full of oil.

RENEWING THE

The left side crankcase oil seal can be removed by

drifting it out of the case from the inside after the

cran kshaft has been removed. lt is advisable to

renew the oil seal even if it does not appear badly

worn. To remove the timing side ball journal

bearing heat the crankcase to approximately'100'C

and drive the bearing from the outside of the case

using a drift.

At this stage inspect the left side roller bearing

whilst the outer race is still retained in the crank-

case and the inner race on the crankshaft. Check

the rollers and the outer race for signs of

pitting or score marks and if suspect replace

the complete bearing. Remove the inner race of

828

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ENGINE B

SECTION B28

REASSEM BLI NG

Place the crankshaft assembly into the drive-side

case. This operation will be simplified if the case is

supported on a large block of wood, deep enough to

keep the end of the shaft clear of the workbench'

Apply a thin coating of jointing compound to the

joint faces of each crankcase half and fit the gearside

case. Replace the three bolts atthefrontofthecase

and the four nuts (two at the base of the cylinder

and two in the primary case).

Tighten bolts and nuts evenly, to avoid distorting

the joint faces. (Alternatively, reassembly may be

carried out with service tool 2167 as shown in Fig.

847.)

Check that the crankshaft assembly rotates quite

freely. lf it does not, then the alignment may be

incorrect and the cause of the trouble must be

rectifi ed.

Fit the crankshaft sprocket distance piece and the

oil pump worm drive thrust washer, each with its

chamfered face outwards. The sprocket distance

piece is available in three thicknesses to provide

accurate alignment of the primary chain in relation

IGNITION

Before carrying out any checl< on the iSnition tim-

ing, the contact points gaP should first be checked

and, ifnecessary, re-adjusted as described in Section

817.

Remove the sparking plug to enable the engine to

be rotated without any resistance due to comPres-

sion. lf the engine is in the frame, it willalso help if

top gear is selected, so that the engine may be

turned either backwards or forwards by rotating

the rear wheel.

THE CRAN KCASE

to the clutch sprocket. The sizes are as follows:-

'2941'297 in.; '309/'312 in.; '3741'377 in.

Reassembly from this Point is descrlbed in

previous sections. Do not omit to replace

keys in the ends of the shafts before fitting

pinions or sprockets.

Fig. B42. Reassernbling crankcases using Service

Tool No' 2167

the

SECTION B.29

TI MING

Before checking the ignition timing, the Piston must

first be set at the recommended position before toP

dead centre on its compression stroke (both valves

closed)-see General Data.

Remove the small inspection cover at the forward

end of the pri mary d rive case to exPose the generato r

rotor. lt will be seen that there are two timing

marks scribed on to the face ofthe rotor and that a

pointer is mounted at the base of the inspection

aperture (as shown in Fig. 843).

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BENGINE

The automatic-advance functions by centrifugal force

acting on spring-loaded bob-weights which will

advance the ignition timing as the engine revolutions

rise. Since exact timing accuracy is required at

operating speeds it is better to time the engine in

the fully advanced position so transferring any var-

iations in the firing to the ticl<-over or low engine

speeds when it can least affect the performance.

Fig. 843, Showing rotor marking

Rotate the engine slowly until the pointer coincides

with the timing mark furthest away from the lcey-

way or the mark nearesr the word "LUCAS".

At this stage the auto-advance unit should be freed

from its taper by removing the centre bolt and

screwing in extractor 61-3816 until the auto-

advance cam is released from its taper. The auto-

advance unit should be rotated until the contact

points are about to open whereupon the bolt

should be refitted to pull the auto-advance cam

back onto the taper.

This will give an approximate

base the final ignition timing. setting on which to

SETTING THE CONTACT BREAKER CAM

The simplest way to set the ignition timing, is to set

it statically.

Unfortunately, due to manufacturing tolerances this

is not the ideal because, whilst it will set the timing

of the engine for tick-over speeds, the firing at wide

throttle openings will vary due to differences in the

amou nt of automatic-advance.

B30

Fig.B,44. Setting the contact breaker cam

Whilst setting the ignition timing, therefore, the

contact breaker cam must be locked in the fully

advanced position.

Carefully remove the central fixing bolt (3) with

washer from the contacr breaker cam (1) and tem-

porarily fit another washer (2) having a hole just

large enough to clear the cam inner bearing (see

Fig. 844), thus allowing the washer to bear againsr

the top face of the cam.

Replace the bolt, but before tightening, rotate rhe

cam in an anti-clockwise direction until the bob-

weights are fully expanded, hold in position and

tighten the bolt. Care must be taken during this

operation to avoid releasing the whole mechanism

from its location.

ALTERNATIVE METHOD

Machines have a plug screwed into the top front of

the left crankcase forward of the cylinder barrel.

Remove this plug and, with the engine at top dead

centre (piston at top of stroke and both valves

closed) fit the timing plunger and body (61-2915 and

D572). Turn the engine backwards gently (by

25W45

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ENGINE B

Fig. B45. Battery and bulb in circuit

turningthe rearwheel) and with slight hand Pressure

on the plunger, this should locate in the hole

provided in the left flywheel. Set the auto-advance

cam in the fully advanced position as previously

described. The ingition timing can then be set as

follows.

SETTING THE IGNITION TIMING

Having locked the contact breaker cam in the fully

advanced position and with the rotor timing mark

set at the pointer, the ignition timing can now be set.

An accurate means of checking the opening of the

contact points can be made by connecting a battery

and bulb in circuit with the points (see Fig. B45).

Attach one lead between the "C" spring and the

battery terminal. Take a second lead from the other

battery terminal to a bulb, then from the base ofthe

bulb to a good earthing point on the machine.

As soon as the contact points oPen, the circuit will

be broken and the light will go out.

Loosen the contact breaker plate pillar bolts and

rotate the plate either clockwise or anti-clockwise

until the points are just oPening.

Use the contact breaker plate adjustment to obtain

as accurate setting as is possible. Then tighten the

pillar bolts and finally set the ignition timing by

using the range offered by the secondary backplate.

This is achieved by loosening the secondary bracket

locki ng screws (see section 817 Fig. 81 7) and ad j usti ng

the eccentric screw. This will enable an accurate

ignition setting to be obtained.

Hold tne plate in this position, tighten the pillar

bolts and re-check the setting. There should be no

change in the fully-open gap setting.

Do not forget to remove the large washer, fitted

remporarily behind the contact breaker fixing bolt,

otherwise the auto-advance mechanism will be

i noperative.

The importance of accurate ignition timing cannot

be over emphasized. Care and patience must be

taken to ensure that the final setting is in accordance

with the recommended figures.

Many dealers possess stroboscopic equipment

designed for setting the ingition timing of engines

accurately, and if any difticulty is experienced in

obtaining the correct setting as detailed above,

advantage should be taken of this service.

CHECKING THE IGNITION TIMING

WITH A STROBOSCOPE

lf the contact breaker setting has been completely

Iost or if the engine has been dismantled a basic static

check and preliminary setting as detailed in previous

pages, must be made in order to facilitate engine

starting for the strobe check.

B3'l

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BENGINE

To proceed, remove the inspection cover at the

front ofthe primary drive case expose the generator

rotor and ignition pointer, as shown in Fig. B43.

Connect the strobelight to a suitable 6 or 12 volt

battery and attach the high-tension lead to the spark

Pl ug.

Start the engine and direct the light on to the

generator rotor. lf the ignition timing is correct,

the pointer and the appropriate mark on the rotor

will line-up when the engine exceeds 3,000 revs per

minute.

Correct any variation by adjusting the contact

breaker plate as detailed in the previous section.

SECTION B3O

FITTING A TACHOMETER

Parts are available through normal spares supply

channels for the fitting of tachometer. There is a

blanking plate on the front of the right crankcase

retained by two screws and this should be removed.

It is necessary to lift the forward end of the engine

in the frame to allow sufficient room to insert the

drive housing. Detach the exhaust system, fuel

tank and cylinder head steady, remove the front and

permit this. The drive housing complete with gear

and shaft can then be slid in, being tapped home

gently with a hammer until the securing flange is

flush with the crankcase.

Fig. 846. Showing

Fig. B47. Speedometer and Tachometer

assembled

The drive gear meshes with the oil pump drive

gears. lf for any reason the drive gear and shaft

need to be separated from the housing note that

there is a driven in peg at the outboard end which

will first have to be removed.

A rev counter mounting plate must be obtained and

fitted in the same manner as the speedometer.

order of assembly of tachometer

drive

B32

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sEcTloN c

CARBURETTER

INDEX

SECTION

DESCRIPTION

C1 STRIPPING AND RE-ASSEMBLING THE CARBURETTER

C2 INSPECTING CARBURETTER COMPONENTS

C3 POINTS TO NOTE

C4 TRACING FAULTS

C5 CARBURETTER ADJUSTMENTS

C6 CORRECTING MIXTURE

C7 TUNING THE CARBURETTER

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cCARBURETTER

,I. FIXING SCREWS

2. ABUTMENT

3. TOP

4. THROTTLE SPRING

5. NEEDLE CLIP

6. JET NEEDLE

7. THROTTLE SLIDE

8. MIXTURE CHAMBER

9. MAIN JET

10. THROTTLE STOP

'11. AIR SCREW

12. WASHERS

'13, 'o'RtNG

14. BOWL GASKET

15. NEEDLE JET

16. MAIN JET HOLDER

17. FLOAT

18. FLOAT HINGE

19. FLOAT NEEDLE

20. BOWL

21. FILTER

22. BANIO BOLT

23. BOWL PLUG

24. SEALING WASHER

Fig. Cl. Exploded view of carburetter

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CARBURETTER c

DESCR,IPTION

The machine is fitted with an Amal carburettor, in-

corporating a concentric float chamber.

The carburetter, because of its jets and chol<e bore,

proportions and atomises just the right amount of

petrol and air which provides a highly inflammable

mixture. The mixture is drawn into the engine and

burnt within the cylinder head and piston crown,

hence the term "combustion chamber."

The float chamber maintains a constant level of fuel

at the jets and incorporates a valve which cuts offthe

supply when the engine stops.

The throttle, being operated from the handlebar

twistgrip, controlsthe volume of mixture and there-

fore the power.

When the engine is ticking-over, the mixture is

supplied through a pilot jet. As the throttle is

opened, the pilot mixture is augmented (via the

pilot by-pass), by the supply from the main jet;

the initial stages being controlled bythe taPer needle

in the needle jet.

The pilot fuel supply is controlled by a small, pressed

in jet situated within the carburetter body. The jet

is not removable.

The main jet does not spray directly into the mixing

chamber, but discharges through the needle jet into

the primary air chamber, and goes from there as a

rich petroiiair mixture into the main a!r chamber.

The primary air chamber has a compensating action

in conjunction with bleed holes in the needle jet,

which serves the double purpose of compensating

the mixture from the needle jet and allowing the

fuel to provide a well outside and around the needle

1et, whlch is available for snap acceleration.

The float chamber is secured to the base of the mix-

ing chamber by two screws with spring washers.

On removal, it will be noted that the float spindle is

a press-fit into the chamber body and that the float

needle is retained in position by the rear forked end

of the float.

The needle jet and main jet (with holder) can now

be unscrewed from the mixing chamber base.

Take out the throttle stop adjusting and pilot air

adjusting screws and ensure that the small rubber

"O" ring on each screw is in good condition before

replaci ng.

The float chamber tickler consists of a spring and

plunger, splayed at one end to retain it in the mixing

sEcTloN cl

STRIFPING AND REASSEMBLING TI-IE CARBI.'RETTER

Disconnect the air filter and release the two fixing

nuts. Withdraw the carburetter from its mounting

studs; it will not be necessary to detach the cable

from the twist griP.

Take out the two Phillips-head fixing screws and

remove the carburetter toP cover complete with

throttle slide assembly. Compress the throttle

spring and remove the needle clip to release the

needle. Whilst still compressing the spring, push

the cable downwards to release the nipple from its

location in the valve. Take care not to lose the need le

clip when taking off the spring and top cover.

Unscrew the "banjo" bolt which secures the fuel

pipe "banjo" connector to the float needle seating

block and withdraw the nylon filter.

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cCARBURETTER

chamber. This item should not be subjected to a

great deal of wear and is therefore unlikely to re-

quire replacement.

Having dismantled the carburetter, carefully clean

all parts in petrol (gasolene). Hard deposits on the

carburetter body are best removed with a light

grade wire brush. After washing the parts in clean

petrol (gasoline) allow to dry and ensure that all

holes or small drillings are free from dirt. A hand

pump is ideal for "blowing through" any blockages

in the drillings. lnspect the component parts for

wear and check that the jets are in accordance with

the recommended sizes given in General Data.

Reassembly is simply a reversal of the above in-

structions but remember to replace any gasl<ets or

"O" rings that appear unserviceable. Refer to

Fig. Cl for guidance.

(4) Check the float needle for efficiency by inserting

it into the float needle seating block, pouring a

small amount of petrol (gasolene) into the

aperture surrounding the needle and checl<ing it

it for leakage.

(5) Ensure that the float is nor puncrured by shal<ing

it to see if it contains any fuel. Do not attempt

to repair a damaged float. lf there is any doubt

about its condition, replace it with a new one.

(6) Check the petrol filter that firs over the needle

seating block, for any possible damage to the

mesh. lf the filter has parted from its supporting

structure it will allow the petrol (gasolene) to

pass through unfi ltered.

sEcTtoN c2

I NSPECTING CARBUR,ETTER CO MPONENTS

The parts most liable to show wear after consider-

able mileage are the throttle valve slide and the

mixing chamber.

(1) Inspect the throttle valve slide for excessive

scoring ofthe front area and check the extent of

wear on the rear slide face. lf wear is apparent,

the slide should be renewed; be sure to fit slide

with correct degree of cut-away (see General

Data).

(2) Check the throttle return springs for efficiency.

Check also that it has not lost its compressive

strength by measuring the free length and com-

paring it with the figure given on page GD3.

(3) Examine the needle jet for wear or possible

scoring and check the tapered end ofthe needle

for similar signs.

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CARBURETTER c

sEcrloN c3

HINTS AND TIPS

THROTTLE CABLT

See that there is a minimum of backlash when the

twist grip is turned bacl< and that any movement of

the handlebar does not cause the throttle to oPen.

Use the adjuster on the cable to obtain the correct

setting and ensure that the throttle slide shuts

down freely.

PETROL FEED

Unscrew the float chamber "banjo" bolt, remove

the "banjo", and take off the filter gauze from the

needle seating.

Ensure that the filter gauze is undamaged and free

from all foreign matter. To check fuel flow before

replacing the "banjo", turn on petrol tap momen-

tarily and see that fuel gushes out.

FLOODING

This may be due to a worn needle or a punctured

float, but is more likely due to imPurities (8rit, fluff'

etc.) in the tank. This trouble can sometimes be

cleared by periodically cleaning out the float

chamber. lf however, the trouble persists, the tanl<

must be drained and swilled out.

CARBURETTER AIR LEAKS

Erratic slow-running is often caused by air leaks

between the joints at the carburetter flange and the

cylinder head and can be detected by applying oil

around the joints. Eliminate by fitting new washers

and tightening the flange nuts evenly to the torque

wrench setting given in General Data.

Also check that the rubber sealing ring in the car-

buretter flange is undamaged and located correctly.

On high mileage machines lool< for air leaks caused

by a worn throttle or a worn inlet valve guide.

BANGING, IN EXHAUST

This may be caused by too weak a pilot mixture

when the throttle is closed or nearly closed' lt may

also be caused by too rich a pilot mixture and an air

leak in the exhaust system. The reason in either

case is that the mixture has not fired in the cylinder

but has fired in the hot silencer.

lf the banging occurs when the throttle is fairly wide

open, the trouble will be traced to ignition, not

carbu ration.

EXCESSIVE PETROL CONSUMPTION

lf this cannot be corrected by normal adjustments,

it may be due to flooding caused by impurities from

the petrol tanl< lodging on the float needle seat, so

preventing its valve from closing. The float needle

should also be checked for wear or damage.

High consumption can also be caused by a worn

needle jet and may be remedied or improved by

lowering the needle in the throttle. lf this method

is unsatisfactory, then a new needle and needle iet

will have to be fitted.

There are many other causes of high petrol con-

sumption and it should not be assumed that the

fault lies in the carburetter alone.

AIR FILTERS

lf a carburetter is first set with an air filter and the

engine is then run without, the jet setting may be

affected and care must be taken to avoid overheating

the engine due to too weak a mixture. Testing with

the air supply will indicate if a larger main iet and

higher needle position are required.

EFFECT OF ALTITUDE ON A

CARBURETTER

lncreased altitude tends to produce a rich mixture;

the greater the altitude, the smaller the main jet

required. Carburetters ex-works are suitably set

for use in altitudes of u p to aPProximately 3,000 feet.

Carburetters used constantly in altitudes of between

3,000 to 6,000 feet should have a reduction in main

jetsize of 5/,. A further reduction of 4/" should

be made for every 3,000 feet in excess of 6,000 feet

altitud e.

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cCARBURETTER

sEcTtoN c4

TRACING FAULTS

Faults likely to occur in carburation can be placed in

one of two categories; either richness or weal<ness

of petrol/air mixture.

INDICATIONS OF RICHNESS

Black smoke in exhausr.

Petrol spraying out of carburetter.

Eight-stroking.

Heavy lumpy running.

Sparking plug sooty.

INDIEATIONS OF WEAKNESS

Spitting back in carburetter.

Erratic slow-running.

Overheati ng.

Engine goes better if throttle is almost closed.

Having established whether the mixture is too rich

or too weak, check if caused by:-

(1) Petrol feed-check that jets and passages are

clear, that filter gauze in float chamber "banjo"

connection is not choked with foreign matter,

CARBU RETTER

(A) Throttle Adjusting Screw

Set this screw to hold the throttle open sufficiently

to keep the engine running when the twist grip is

shut off.

(B) Pilot Air Adjusting Screw

This screw regulates the strength of the pilot

mixture for "idling" and for the initial opening

ofthe throttle. The screw controls the depression

on the pilot mixture chamber by metering the

amount of air that mixes with the petrol.

The main jet controls the petrol supply when the

throttle is more than three-quarters open, but at

and that there is arnple flow of fuel. Also ensure

there is no flooding.

(2) Air leaks-usually ar rhe flange joint or due to

worn inlet valve stem and guide.

(3) Defective or worn parts-such as a loose-fitting

throttle valve, worn needle jet, Ioose jets.

(a) Air cleaner cholced-up.

(5) An air cleaner having been removed.

(6) Removal of the silencer-this requires a richer

setti ng.

Having ensured that the fuel feed is correct and that

there is no air leak etc., checl< the ignition, valve

operation and timing. Test to see if the mixture

is rich or weak by partially covering the carburetter

iniet and noting how the engine runs. lfthe engine

runs better, weakness is indicated, but if the engine

runs worse then the mixture is too rich.

For suggested remedies see Section C6.

sEcTroN c5

AD.! USTMENTS

smaller throttle openings although the supply

fuel goes through the main jet, the amount

diminished by the metering effect of the needle

the needle jet.

Each jet is calibrated and numbered so that its

exact discharge is l<nown and two jets of the same

number are alike. Never ream out a jet, get

another of the right size. The bigger the number

the bigger the jet.

To gain aecess to the main jet remove the plug from

the base ofthe float chamber and unscrew the nrain

jet using a small box spanner.

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CARBURETTER c

(D) Needle and Needle Jet

The needle is attached to the throttle valve and

being tapered either allows more or less petrol to

pass through the needle jet as the throttle is

opened or closed throughout the range, excePt

when idling or at nearly full throttle. The taPer

needle position in relation to the throttle opening

can be set according to the mixture required by

fixing it to the throttle valve with the jet needle

clip in a certain groove. thus either raising or

lowering it. Raising the needle richens the mixture

and lowering it weakens the mixture at throttle

openings from quarter to three-quarters oPen.

(E) Throttle Valve Cut-away

The atmospheric side of the throttle is cut away to

influence the depression on the main fuel supply

and thus gives a means of tuning between the pilot

and needle jet range of throttle opening' The

amount of cut-away is recorded by a number

marked on the throttle valve, viz. 900/3{ means

throttle valve type 900 with number 3+ cut-away;

larger cut-aways, say 4 and 5, give weaker mixtures

and2arichermixture.

(F) Tickler or Primer

This is a small spring-loaded plunger, in the car-

buretter body. When pressed down on the float,

the needlevalve isallowed tooPen and so "flooding"

is achieved. Flooding ternporarily enriches the

mixture until the level of the Petrol subsides to

normal.

TO CURE

Position 1.

Position 2.

Position 3.

Position 4.

TO CURE

Position 1.

Position 2.

SEerloN c6

EORRECTING MIXTURE

RICHNESS

Fit smaller main jet.

Screw out pilot air adjusting screw.

Fit a throttle with a larger cut-away

(see paragraph E, Section C5).

Lower needle one or two grooves

(see paragraph D, Section C5).

w'EAKNESS

Fit larger main jet.

Screw pilot air adjusting screw in.

Position 3. Fit a throttle with a smaller cut-away

(see paragraph E, Section C5).

Position 4. Raise needle one or two grooves (see

paragraph D, Section C5).

(Positions 1,2, 3 and 4 refer to Positions of throttle

openings as shown in Fig. C2, Section C7).

Note. lt is incorrect to attemPt to cure a rich mix-

ture at half-throttle by fitting a smaller jet because

the main jet may be correct for power at fu ll th rottle.

The correct method is to lower the throttle needle.

CARBURETTER

With the correct size of main jet, the engine at full

throttle should run evenly and regularly with

maximum Power.

lf testing for speed work, ensure that the main jet

size is sufiicient for the mixture to be rich enough

to maintain a cool engine. To verify this, examine

the sparking plug after taking a fast run, declutching

and stopping the engine quicl<ly. lf the sparking

plug has a cool appearance the mixture is correct;

if sooty, the mixture is rich; if, however, there

are signs of intense heat, the plug being very white

sEcTrol{ c7

TUNING THE

Read the remarks in Section C5 for each tuning

device and get the motor going perfectly on a quiet

road with a slight up-gradient so that on test, the

engine is pulling under load. Set carburation in the

following order:

1st. Main Jet with throttle in position 1 (Fig. C2).

lf at full throttle the engine runs "heavil/", the

main jet is too large. If, at full throttle, the engine

seems to have better Power when the throttle is

eased off or the carburetter intake is slightly

covered, then the main jet is too small.

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cCARBURETTER

uP To 2e oprNr

PITOT JET

2nd. & sth.

FRoM y'aroy'qoPEN

THBOTTIE CUT AWAY

FRoM 2qto3/qoPEN

IUEEDI-E - POSITION

4th.

%rorut oPEN

MAIN JET SIZE

in appearance, the mixture is too weak and a

larger main jet is necessary.

2nd. Pilot Mixture (Fig. C2)with rhrottle in posi-

tions 2 and 5. With the engine idling too fast, the

twist grip shut off and the throttle shut down on to

the throttle ad justing screw: (1) Screw our rhe

throttle adjusting screw until the engine runs slower

and begins to falter, then screw pilot air adjusting

screw in or out, to make engine run regularly and

faster. (2) Now gently lower the throttle adjusting

screw until the engine runs slower and just begins to

falter, adjust the pilot air adjusting screw to get

best slow-running, if this second adjustment leaves

the engine running too fast, go over the job a third

time.

3rd. Throttle Cut-away with throtrle in position

3 (Fig. C2). lf, as you take off from the idling

position, there is spitting from the carburetter,

slightly richen the pilot mixture by screwrng rn the

air screw. lf this is not effective, screw it back

3rd. 4th,

Fig. C2. Sequence of adjustment

1st.

again, and fit a throttle with a smaller cut-away.

lf the engine jerks under load at this throttle

position and there is no spitting, either the jet

needle is much too high or a larger throttle cut-

away is required to cure richness.

4th. Needle with throttle in position a fig. C2).

The needle controls a wide range of throttle open-

ings and also the acceleration. Try the needle in

as low a position as possible, viz. with the clip in a

groove as near the top as possible; if acceleration

is poor and with the carburetter inlet partially

covered, the results are better, raise the needle by

two grooves; if very much better try lowering the

needle by one groove and leave it where it is best.

lf mixture is still too rich with clip in groove

number 1 nearest the top, the needle jet probably

wants replacement because of wear. lf the needle

itself has had several years' use replace it also.

5th. Finally, go over the idling again for final

tou ches.

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SECTION D

FRAME

INDEX

SECTION

D1 FRAME ALIGNMENT

D7 CHAINGUARD REMOVAL

D3 REAR SUSPENSION UNITS

D4 REMOVING THE SWINGING ARM

D5 SWINGING ARM BEARINGS

D6 CHECKING SWINGING ARM ALIGNMENT

D7 TWINSEAT

D8 PROP STAND

D9 REAR BRAKE PEDAL

D1O MUDGUARDS

D11 AIR CLEANER

D17 ELECTRICAL BOX-DISMANTLING PROCEDURE

D13 BATTERY CARRIER AND TOOLBOX

D14 REMOVAL OF HEADLAMP

D15 PETROL TANK REMOVAL

D16 APPLYING TRANSFERS (DECALS)

D17 CENTRE STAND (WHERE FlrrED)

D18 CONTROL CABLE REPLACEMENT

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DFRAME AND FITTINGS

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FRAME AND FITTINGS D

SECTION DI

FRAME ALIGN MENT

The only satisfactory way of checking the frame for

correct alignment is on an engineers settinS-out

table. ln addition to the table, which should be

approximately 5ft. x 3ft., the following equiPment

will also be necessary.

One mandrel See Fig. D2 for dimensions.

One mandrel or bar for swinging arm pivot fin.

diameter x 12 in. long.

One large set-square.

One 18 in. Vernier height gauge or large scribing

block.

One pair of large "V" blocks and several adjust-

able height jacks.

lf a scribing block is used, then an 18 in. steel rule

will also be required. The mandrels must be

straight and round, otherwise measurements will

be affected. Figure D2 shows the basic set-up for

checking the frame, though variations can of

course be used according to the facilities available.

Place the roller bearings in the steering head, insert

the mandrel and support with the "V" blocks at one

end ofthe table. Check the mandrel at each end to

ensure that it is parallel with the surface of the

table. lnsert the flin. diameter mandrel through

the swinging arm pivot hole.

Now, using jacks or packing pieces, set the frame

horizontal to the table so that checks taken at

points (A) are the same.

lf the frame {ras-suffered damage in an accident, it

may not be possible to set points (A) parallel in

which case points (B) can be used.

Sometimes if the machine has been subjected to a

frontal impact, the main tube may remain parallel

at points (A) but will be arched. A straight-edge

made from a piece of good quality hardboard can

be used for this purpose, but the checking edge

must be quite straight.

%Dlax 16thd uNF

va DtA

Fig. D2. Showing frame on setting table

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DFRAME AND FITTINGS

When the frame is set parallel to the surface table,

the mandrel through the swinging arm plvot holes

should be vertical. This can be checked using the

set-square and internal calipers or a slip gauge

between the mandrel and the square. The set-

square should touch both the upper and lower

tubes together at points (C) and (D) if the frame is

true and correctly set-up on the table. To find the

frame centre line, take the height of the main tube

and subtract halfthe diameter ofthe tube.

Checks can now be taken at the engine mounting

lugs and other points of the frame. Errors at any

point should not exceed $ in. (.79 mm.).

The chainguard extension at the front is fixed to the

crankcase by a bolt with one plain and one spring

washer beneath the head, and the rear mounting

bracket is slotted between the top left engine plate

and the frame bracl<et. After removal of the bolt at

the front and loosening ofthe rear nut the extension

can be pulled away.

I-he rear shock absorbers, or dampers, are of the

coil-spring type, hydraulically damped and are

mounted on bonded rubber bushes at each end.

The actual damping unit is a sealed assembly and

the only dismantling that can be carried out is for

the removal and replacement ofthe springs.

To remove a damper, take out the top fixing bolt

with nut and washers and unscrew the lower fixing

self-locking nut at cupped dust cover. Pull the

damper off the stud at the bottom and withdraw

from the top frame bracket.

It necessary the removal and replacement of the

mounting bushes will be found much easier if a little

liquid soap is applied.

SECTION D2

CHAINGUARD REMOVAL

The chainguard is secured at the front by a bolt

passing through a bracket on the swinging arm, and

at the rear by the bottom fixing bolt for the sus-

pension unit.

Remove the bolt at the front and loosen the nut ar

the suspension unit and lift the chainguard away

from the machine.

SECTION D3

REAR SUSPENSION UNITS

The damper springs are graded at 100 lb.i in. rate.

The damper positions are shown in Fig. D3 and they

must be set in the "light load" position before

dismantling. A "C" spanner for this adjustment is

provided in the toolkir.

To remove the spring grip the bottom lug of the

suspension unit in a vice, grasp the spring in both

hands and pull down until the spring is sufficiently

compressed to allow the spring retainers to be

removed by a second operator.

The damper unit should be checked for leakage,

bending of the damper rod and damping action.

Reassembly is a reversal of dismantling. Check

that the cam is in the light load position before

compressing the spring.

Turn left

to harder

position

D4 Fig. D3. Cam ring adiustment

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FRAME AND FITTINGS D

r __---(e

- A1'!'

l-------1lt)t) ),

wtl

Fig. D4, Exploded view:of suspension unit

1. ADJUSTER CAM

2. SWING ARM SPINDLE

3. SPACER TUBE

4. NEEDLE ROLLER BEARING

5. OIL SEAL

6. BEARING SLEEVE

7. THRUST WASHER

8. DUST EXCLUDER

1. DAMPER UNIT

2. BUMP STOP

3. ALLOY SPACER

4. ADJUSTER

5. SPLIT COLLAR

6. SPRING

7. BONDED BUSH

Fig. D5. Swinging arm assembly details

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DFRAME AND FITTTNGS

SECTION D4

REMOVING THE

Take off the rear wheel, chainguard, dampers and

rear brake pedal as described in Sections F6, D2,

D3, and D9 respectively.

The rear stoplight switch situared behind the rear

brake pedal must be allowed to swing clear of the

swinging arm cam adjuster. This is achieved by

removing the rearmost attachment bolt. Note

assembly of spacer and washers for this bolt, (the

spring washer sits underneath the head ofthe bolt).

Remove the swinging arm spindle nut from the right

SWINGING ARM

side and withdraw the spindle from the left side

whilst supporting the swinging arm. Disconnect the

snap connectors in the rear harness. They are

situated near the left side top suspension unit

mounting.

Remove the five bolts securing the mudguard to

the frame and remove the mudguard. lt will now be

possible to wirhdraw the swinging arm from the

frame. Assembly details of the swinging arm

bearings, seals and end cups are shown in Fig. D5.

SECTION D5

S\ilINGING ARM BEARINGS

The swinging arm bearings consist of two precision

needle roller bearings that run on ground steel

bushes separated by a distance tube. The bearings

are lubricated on assembly and have a long service-

able life. However to cope with extremely dirty

conditions grease nipples are fitted to later swinging

arms and these can be employed to grease the

bearings when the necessity arises. (See Section A2

for grease specifi cation).

Under normal conditions the bearings have a long

serviceable life. But ifthe bearings are suspected for

wear then they will have to be removed using a

suitable d rift.

The bearing spacer tube hinders direct application

of the drift. But it will be found that the spacer tube

can be drifted from one end and out through one

needle roller bearing. This will leave the support

rings that were previously pressed onto the spacer

tube lying loose in the swinging arm housing.

It will now be possible to drift out the needle roller

bearings. Make sure that the end of the drift does

not have a sharp edge that may dig into the housing.

The spacer tube assembly will have to be replaced

when renewing the bearings.

When replacing the needle rollers use a suitable

drift and ensure thar the bearing is square with the

housing before using the drift. Replace the new

spacer tube assembly from the opposite side and

finish with the remaining bearing. Note the assembly

of all seals and thrust washers. (See fig. D5 page D5

for details.)

SECTION D6

CHECKING SWINGING ARM ALIGNMENT

Before checking the swinging arm alignment, it must

be establ ished that the beari ngs are i n good cond ition.

Using the same mandrel that was used for the

swinging arm pivot on the frame (see page D3),

set the swinging arm in "V" blocks as shown in

Fig. D6. Another mandrel 12in. long x $in. diameter

should be inserted through the fork ends. Both

mandrels should be parallel to the surface table.

Should there be less than f in. malalignment of the

swinging arm fork it is permissible to correct it by

means of a suitable lever but, care must be taken

to avoid causing further damage.

To check that the forks are square ro the pivot,

chey must be set-up at 90' to the position illus-

trated, so that the pivot is vertical. Next, find the

centre of the pivot and check that the fork ends

etc., are in accordance with the dimensions shown

in Fig. D7.

When there is considerable malalignment in either

frame or swinging arm, it is recommended that a

works reconditioned unit is fitted.

Note. There may also be a variation in the rear

dampers and a careful examination should be made

of the overall length between the mounting eyes.

It is possible that one damper may be weaker than

the other, caused by the "settling" of a spring.

lf this should be the case, it is advisable to renew

the springs in both dampers.

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FRAME AND FITTINGS D

Fig, D6. Checking the swinging arm

Fig. D7. Swinging arm dimensions (All dimensions are in inches)

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t) FRAME AND FITTINGS

SECTION D7

TWIN SEAT

The twin seat is mounted at two points in mid-

position and supported in a slotted bracket at the

front.

To remove the sear unscrew the two bolts from

underneath the seat and slide the seat rearwards

and away from the machine.

Replace in the reverse order, making sure that the

front fixing is engaged correctly in the slot.

SECTION D8

PROP STAND

With the stand in the raised position remove the

"Nyloc" nut from the spindle bolt. Using a screw-

driver remove the slotted head bolt from the inside

of the frame.

Swing the leg into the upright position and by

doing so lever the leg against the stop and remove

from the machine.

Detach the return spring.

Replacement is the reversal of the removal proce-

dure.

SECTION D9

REAR BRAKE PEDAL

Remove the clevis pin that secures the bra(e rod

to the brake pedal and allow the rod to swing

cl ear.

SECTION D IO

M UDG UARDS

T25T: Remove the two attachment bolts at the

bracket suspended by the bottom yolk. Withdraw

blade from between the forks.

T25SS: To detach the mudguard remove the joint

bolts securing the retaining brackets to the fork

legs. Note that the brackets are in two parts sur-

rounding a rubber bush. Hence the mudguard is

completely rubber mounted.

The rear mudguard can be removed complete with

its support rail rear light and number plate. Remove

Remove the spindle by unscrewing the locknut

from inside the frame.

Replacement is the reversal of the above.

the twinseat (see Section D7). Disconnect the rear

harness at the junction snap connectors situated

near the top of the left side suspension unit.

Remove the five bolts and nuts securing the mud-

guard to the frame. Then remove the mudguard

from the rear ofthe machine.

Replace the mudguard in the reverse manner and

checl< that the rear light cables are not damaged at

any point.

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FRAME AND FITTINGS D

SECTION DII

AIR CLEANER

The carburetter air cleaner is ofthe disposable paper

element type. lf the machine is to be used under

very dirty and dusty conditions, the cleaner should

be changed regularly, e.g. every 1000 miles. Running

the machine with a badly choked air cleaner will

cause restricted maximum speed, and increase in

fuel consumption and many other carburation

trou bles.

The ai r cleaner is contained behind the left side

cover. This cover is removed by applying half a turn

to the quicl< release screw in the toP corner- To

detach the element, remove the securing nut and

withdraw the element.

Note. On no account should attem Pts be made to

clean the element with comPressed ai r or a solvent

of some kind; this would undoubtedly damage the

delicate structure.

Refer to fig D8 for details of the assembly'

SECTION D 12

ELECTRICAL BOX_DISMANTLING PROCEDT-'RE

All the electrical comPonents comprising of the

ignition coil, 2MC caPacitor, ignition caPacitor,

rectifier, ignition switch and zener diode are con-

tained in a cast aluminium electrics box, (see fig.

G1, Section G), attached to the frame beneath

the fuel tanl<. lf access is required for the PurPose

of replacing faulty components etc., the procedure

is as follows:

(1 ) Remove the petrol tanl<. See section D1 5'

(2) Disconnect all external connectiotls Protruding

from the box. Disconnect the oil Pressure

switch at the crankcase. Disconnect the H'T.

lead at the coil and remove the front harness

junction plug (see Fig. D10). Disconnect the

horn. lt will be easier to remove the electrical

box with the horn and bracket still attached

than to remove the box alone.

(3) Remove the three retaining nuts attaching the

electrical box to the frame and withdraw it

away from the machine.

Fig. D8. Air cleaner

(4) Remove the four bolts securing the lid of the

electrical box and raise the lid from the open

end towards the rear. At this Point disconnect

the zener diode (the large lucar connection on

the underside of the lid).

(5) Disconnect the coil and then remove the two

pozidrive screws retaining the coil securing clip

and remove the coil from the box.

(6) Disconnect the caPacitor and flasher unit

contained in the large rubber moulding. Remove

the two screws securing the moulding to the box

and remove. As the moulding comes away

disconnect the ignition caPacitor from under-

n eath.

(7) Disconnect the iSnition switch and remove

from the box.

(8) Disconnecl the rectifier and detach it from the

casing by removing the retaining nut from the

outside wall of the box.

(9) Remove the two remaining screws securing the

junction box and remove.

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DFRAME AND FITTINGS

SECTION D 13

BATTERY CARRIER AND TOOLBOX

Remove twinseat (see Section D7).

Access to the battery and tooltray is gained by

removing the left and right-hand side covers. These

covers are held in position by special screws that

only require half a turn to release.

Disconnect the battery terminal connections, unclip

the fixing strap and lift out the battery. Note that a

vent pipe is connected to the battery top and is so

arranged that corrosive fumes from the battery cells

are directed clear of the machine.

The battery carrier and the tooltray are attached to

the machine by two common bolts running through

the top main tube. When these two bolts are

removed, the battery carrier and tooltray can be

removed from the machine. Note assembly of

rubber bushes, washers and support grommet

when reassembling (see fig. D9).

The rubber bushes help to insulate the battery and

carrier from road shocks and vibration; therefore it

is important to ensure correct reassembly.

Fig. D9 Battery carrier assembly

SECTION DI4

REMOVAL OF HEADLAMP

Remove the petrol tank (see Section D15). Dis-

connect the front harness at the electrical box (see

fig. D10). Pull harness through the forks clear ofthe

machine. Remove any clips securing the harness to

the frame.

Remove the two retaining nuts at the fork bottom

yolk pinch bolts.

Unscrew the two domed nuts at the top yolk and

detach the headlamp from the forks.

Remember to adjust the headlamp to give the

correct beam setting as detailed in section G13.

D10

Fig. Dl0. Master electrical iunction.

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FRAME AND FITTINGS D

Turn off both petrol taps and detach the petrol pipes

from the taps by unscrewing the pipe union nuts.

The petrol tank can be removed from the machine

without disturbing the twinseat. But if difficulty is

obtained with clearance at the rear ofthe tank, the

seat should be removed as described in section D7.

The tank on the T25T is made of light aluminium

alloy and should not be abused in any way.

Remove the rubber grommet at the centre of the

tank and remove'the nut revealed. Pull off the

washer and then pull the tanl< away from the

mach ine.

Note assembly of the

top frame tube. Fig. Dll Showing two types of mounting

T25SS shown on the left

SECTION D 15

PETROL TANK REMOVAL

rubber buffers that sit on the

to the transfer. Remove the tissue from the face o

the transfer and separate one edge of the backing

from the actual transfer to facilitate removal at a

later stage. Varnish the face ofthe transfer and allow

to dry for five minutes. Then place the tacky side of

the transfer on to the part to which the transfer is

to be fixed and carefully remove the thick backing

PaPe r.

Allow to dry for half an hour or so and then moisten

the remaining backing paper with a wet rag or

sponge. lt can then be removed and the transfer

must be varnished to preserve it.

SECTION D 16

APPLYTNG TRANSFERS (DECALS)

It should be noted that two types of transfers

(decals) have been used on our models. These are

are the traditional varnish applied type and the

self-ad hesive type.

Applying the self-adhesive type is merely a matter

of removing the baclcing paper and pressing down-

wards onto the painted surface.

Applying the varnish type is slightly more difticult

but with care a perfect finish will be achieved.

Firstly cut away the paper edging as close as possible

D11

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DFRAME AND FITTINGS

SECTION D 17

CENTRE STAND

The frame has provision for a centre stand and it is

fitted as standard equipment on Home and General

Export models.

(wHERE FTTTED)

The stand is attached to the

bolts and locknuts and uses

frame with two special

a return spring.

REPLACE M ENT

valve with the slot in the mixing chamber and fit

the top cap. Do not tighten the cap fixing screws

until the throttle valve has been checked for

correct operation.

Finally, attach the cable to the frame, replace the

cable stop at the twist grip and adjust the cable as

necessary (see Section C3).

CLUTCH CABLE

Unscrew and remove che handlebar lever fulcrum

bolt and nut. Slacken the cable adjuster and swing

the control lever away from the bracket, allowing

the cable nipple to be released.

The adjuster and cabie can now be withdrawn

from the bracket. lt will now be possible to release

the nipple at the other end of the cable from the

clutch actuating lever.

Replace the cable in the reverse manner and adjusc

as necessary to give correct oPeration.

Note. After adjustment, the control lever on the

timing cover should take up a position approxi-

mately parallel with the timing cover joint face,

when operated.

FRONT BRAKE CABLE (TWIN LEADTNG

sHoE BRAKE)

To remove the cable, first slacken the adjustment

at the handlebar lever. Push the inner cable through

the nipple bush in the front brake lever (at wheel)

until the cable nipple is clear of the counterbore in

the bush. Withdraw the bush from the lever and

collect two washers. Slide the tension spring offthe

cable from the rear brake lever (at wheel). Collect

the bush from the lever. Finally remove nipple from

handlebar lever.

SECTION D 18

CONTROL CABLE

THROTTLE CABLE

First turn the twist grip to open the throttle, then,

whilst pulling the cable sleeve, release the grip to

allow the slotted cable stop to be removed. Now

remove the two screws from the twist Srip control

and take offthe top half to expose the cable nipple.

Ease the nipple out of the grip and remove the

cable.

Fit the replacement cable to the grip by inserting

it up through the lower half and locating the

nipple in its slot. Replace the top half of the grip,

but, before tightening the screws, check that the

grip turns freely. Do not replace the cable stop

at this stage.

Proceed by removing the petrol tank (see Section

Dl 5) and detaching the cable from the frame clips.

Take out the two Phillips-head fixing screws and

withdraw the carburetter top cover complete with

throttle valve assembly. Compress the throttle

spring, raise the needle with clip and after making

careful note of its position, remove the needle clip

to release the needle. Whilst still compressing the

spring, push the cable downwards to release the

nipple from its location in the valve. Take care

not to lose the needle clip when taking off the

spring and top cover.

First pass the replacement cable through the cable

guide bracket then insert the cable through the

top cap, spring and needle clip. Whilst compressing

the spring, insert the cable nipple through the

valve needle hole and locate to one side. Fit the

valve needle and secure with the spring clip in the

correct needle groove (second from the top).

Assemble the throttle valve to the carburetter

body, making sure that the needle enters the

needle iet squarely. Locate the peg on the throttle

D12

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FRAME AND FITTINGS D

To replace the cable, Position the cable abutment

bush in the rear brake lever and pass the cable

th rough it.

Ensure that the cable abutment locates cor-

rectly in the counterbore. (See Fig. D12).

Replace the tension spring. Position the end of the

cable inner between the fork of the front brake

lever and position a steel washer to the outside of

the cable. Hold the washer in this position by press-

ing the cable against the fork. Pass the cable nipple

bush through the lever, washer and over the cable

and position the steel washer on the inside of the

inner cable. Push the bush through the second wash-

er and locate the cable nipple in the counterbore.

FRONT BRAKE CABLE (SINGLE LEADING

sHoE BRAKE)

To remove the front brake cable, first comPletely

loosen the cable adjusters and pull the cable adjuster

away from the handlebar lever bracket and slip the

cable nipple out of the lever. ln the case of cables

fitted with a front stop switch it is also necessary to

disconnect the spade terminals.

Replacement is sim ply a reversal of the above

procedures but do not omit to re-adjust the brake

cable and test the efticiency ofthe brake thoroughly

before using the machine.

i-annre LEveR

COBRECTLY SEATED

BRAKE CABLE

Fig. Dl2, Front brake cable abutment'

D13

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SECTION

SECTION E

TELESCOPIC FORKS

INDEX

DESCRIPTION

STEERING HEAD ADJUSTMENT

RENEWING HEAD RACES

STRIPPING AND REASSEMBLING THE FORK LEGS

FORK ALIGNMENT

HYDRAULIC DAMPING

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ETELESCOPIC FORKS

DESCRI PTIO N

The front forl< is of the telescopic type using high

grade steel tube stanchions. They are ground to a

micro finish and hard chromium plated over their

entire length.

The alloy bottom members are precision bored and

provide the bearing for the stanchion. lnternal

main springs are fitted and locate on the damper

tu be.

An oil seal is contained in the top lip of each bottom

member and is protected by a rubber dust cover.

Oil is contained in each bottom member and serves

the dual purpose of damping and lubrication. Oil is

added by removal ofthe fork cap nuts and drained at

the plugs provided.

Damping of the fork action is achieved by the use of

a damper valve in conjunction with a series of bleed

holes in a fixed valve.

ADJ USTMENT

in the races but great care must be taken not to

overtighten, or the rollers will become indented

into the races, making steering extremely difficult

and dangerous.

Having carried out the adjustment, tighten the

clamp nuts and the top yol<e pinch bolt securely.

Re-check the adjustment.

SECTION E I

STEERING HEAD

It is most important that the steering head bearings

are always correctly adjusted.

Place a strong support underneath the engine so

that the front wheel is raised clear of the ground

then, standing in front of the wheel, attempt to

push the lower fork legs backwards and forwards.

Should any play be detected, the steering head

must be adjusted.

lf possible, ask a friend to place the fingers of one

hand lightly round the head lug, whilst the forks

are being pulled back and forth. Any play will be felt

quite easily by the fingers.

It should be possible to turn the forks from side

to side quite smoothly and without any "lumpy"

movemenr. lf the movement is "lumpy", the rollers

are indented into the races or broken. ln either

case the complete bearing should be renewed.

To adjust the steering head assembly, slacken the

clamp nut B, Fig. E'l and the top yoke adjuster nut A

then tighten down the adjuster nut unril adlust-

ment is correct. There should be no play evident

Fig. El. Steering head adjustment

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TELESCOPIC FORKS E

SECTION E2

RENEWING

Place a strong support underneath the engine so

that the front wheel is raised clear of the ground.

Remove the front wheel (see Section F1). Remove

the front mudguard (see page D10).

The steering head can be dismantled without strip-

ping the forks. Remove the fuel tank (see page D11).

With reference to page D'l 0 remove the headlamp

complete with mounting brackets. Disconnect the

speedometer drive cable and the illumination light.

Remove the four bolts securing the handlebars to

the top lug and support the handlebars on the frame.

Remove the fork caP nuts and place the speedometer

to one side. Slacken the top yolk pinch bolt (A) and

remove the adjuster nut (B).

HEAD RACES

Then using a raw-hide mallet stril<e the undersides

of the top lug alternately to release it from its taper

fit on the stanchions. Place the yolk to one side and

withdraw the steering stem out of the head lug.

The taper roller bearings can now be removed from

the stem and the top lug for cleaning and inspection.

Check for pitting and fracture of the roller surface.

The bearing must be replaced if any of these faults

are in evidence.

The steering head outer races have a very long

serviceable life and should not need replacement

for a very considerable mileage. lf however their

replacement is deemed necessary the races can be

removed using a suitable drift from inside the head

lug. Replacement ofthe new race is effected by using

service tool 61-6113.

Remove the internal fork springs. Using service

tool 61-6121 placed down into the stanchion; hold

the valve assembly while the retaining allen screw

is being unscrewed at the base of the fork leg.

At this stage it will be possible to remove the fork

leg by sliding it from the stanchion. The stanchions

can remain in position on the machine and will only

require removal if they are to be replaced because

of damage (the stanchions are easily removed by

slackening the pinch bolts on the bottom yolk and

withdrawing the stanchions. When refitting tighten

the pinch bolts to 18/20 lbs./ft.).

The dust cover on the fork leg can easily be prised

off by hand.

The damper valve assembly is retained in the bottom

of the stanchion by an aluminium nut which should

be carefully removed with a ring spanner or similar.

SECTION E3

STRIPPING AND REASSEMBLING THE FORK I.EGS

Before commencing worl< on the forks it is advisable

to have the following service tools and replacements

available:

(a) Oil seal for dust excluder (2)

(b) Oil seal for damper valve (2)

Remove the front wheel as described in Section F1 .

Unscrew the small drain plugs at the bottom of each

fork leg adjacent to the wheel spindle and drain out

the oil by pumping the forks up and down a few

times. Support the machine on a box with the front

forks clear of the ground. (Remove the front mud-

guard on SS models). Remove the handlebars by

unscrewing the four retaining bolts at the head lug

and lay the handlebars on the petrol tank with a

layer of protective cloth underneath. Remove the

fork cap nuts. Place the speedometer to one side

after first disconnecting the drive cable and the

illuminating light (similar treatment applies to the

tachometer; where fitted).

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ETELESCOPIC FORKS

The valve assembly consists of a fixed bleed valve

which has its own oil seal, a clapper valve, a spring

support nut and a rebound spring. lt should not be

necessary to strip this assembly unless the fixed

bleed valve has contracted damage in any way.

The oil seal on the bleed valve can easily be replaced

by hand. lf using a screwdriver to prise the seal

away from the valve be careful not to damage the

bearing surface as the material is a soft alloy. (Refer

to fig. E2 for details of the assembly).

Care must be taken not to lose the sealing washer

contained in the bottom of the fork leg. The base

of the valve stem rests on this seal and the allen

screw is replaced from the outside of the leg. Refer

to the exploded drawing on page E6 for assembly

details.

The oil seal contained in the top of the fork leg can

be removed with a tool of the design shown in

fig. E3. This tool can be simply manufactured from a

strip of mild steel material approx. 12in. long x 1in.

wide and *-*in. depth. The design is such that the

tool does not come into direct contact with the

aluminium fork leg thereby causing unreparable

damage.

As an alternate a long tyre lever carefully used will

be found adequate. Note. When using either of

these tools make several attempts to remove the

seal by working around the periphery of the fork

leg, otherwise the tool will rip through the lip of

the seal.

Make sure the housing for the seal is clean and free

from burns at the top edge and drift the new seal

into the housing using the following method:-

Place the bore stanchion into the fork leg and place a

small polythene bag over the top lip of the stanchion.

Push the oil seal over the stanchion and down into

position on the fork leg. lt is important that the

Fig. E2. Assembly of bleed valve.

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TELESCOPIC FORKS E

Fig. E3. Removing the oil seal from the fork leg.

polythene is used because the lip of stanchion has a

sharp edge that may easily scratch or damage the

precision edge of the seal. Even a scratch that may

not be readlly visible to the eye will cause leakage

at the seal. A drift will be required to replace the

oil seal into the housing. This can be simply fabri-

cated from an early type steel forl< outer member.

A turned shoulder will have to be machined and

brazed or welded to one end of the fork leg. See

fig. E4 for details. lt is important to assembly the

oil seal with the stanchion in position because the

seal must sit squarely in the counterbore otherwise

leakage will occur.

The stanchion can now be removed.

Checl< all components for cleanliness and wash in

fuel if necessary. Examine the bore of the stanchion

and clean with a cloth pushed into the bore.

Reassembly of the forl< leg is a reversal of the dis-

mantling procedure. Replace the valve into the bot-

tom of the stanchion. Apply some red loctite to the

aluminium retaining nut and tighten to a torque

of25 ft./lbs.

Check that the small "Dowty" sealing washer is

located in the well in the base of the fork leg. (lf this

washer shows signs of damage or wear it must be

replaced).

Fig. E4. Replacing the oil seal.

Push the rubber dust cover onto it's location groove

on the forl< leg and then replace the leg on the

stanc h ion.

As the leg is refitted onto the stanchion the stem of

the damper valve assembly must be located on top of

the "Dowty" sealing washer. lf difficulty is encoun-

tered during this operation, service tool 61-6171

which is used to retain the valve assembly while it

is being removed may be used to navigate the damper

valve onto its location.

The allen screw can then be replaced into the bot-

tom of the forl< leg and tightened as described

above.

Replace the fork springs and refill the fork legs with

the correct quantity ofoil. Replace the fork cap nuts

including the speedometer (and tachometer, where

fitted) and tighten them to a torque of 40 ft./lbs.

Reconnect the speedometer drive and illumination

light.

Replace the handlebars (see Section A17). Replace

the front mudguard (SS models only, see Section

D10). Refit the front wheel (see section F1).

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ETELESCOPIC FORKS

a-\

d,ap

(_ \?

q5-

/1fl

///

)-\:/t

I\Y

Q/4

t/-

Fig. E5. Fork assembly details

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TELESCOPIC FORKS E

1. HEAD BEARINGS

2. MAIN SPRING

3. OUTER MEMBER OIL SEAL

4. SCRAPER,SLEEVE

5. DAMPER VALVE 'O' RING

6. RECOIL SPRING

7. PLASTIC SLEEVE

8. DAMPER TUBE

9. DAMPER TUBE CAP SCREW

.IO. BLEED HOLES_DAMPER TUBE

Fig. 6. Sectional view of assembled fork leg.

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ETELESCOPIC FORKS

SECTION E4

FORK ALIGNMENT

After replacing the fork legs, mudguard and wheel,

it may be found that the fork is incorrectly aligned.

To rectify this, the fork wheel spindle cap nuts must

first be screwed up tight on rhe right-hand leg and

the spindle cap on the left-hand leg slackened off.

Also loosen rhe top caps and the pinch bolts in both

the bottom and top yokes. The forks should now be

pumped up and down several times to line them up

and then tightened up from bottom to top, that is,

wheel spindle, bottom yoke pinch bolts, top caps

and finally, the steering stem pinch bolt in the top

yoke.

lf, after this treatment, the forks still do nor

function satisfactorily then either the fork stan-

chions are bent or one of the yokes is twisted.

The stanchions can only be accurately checked for

straightness with special eguipment such as a

surface plate. Special gauges are also required to

check the yokes. lt is possible, however, to make

a reasonable check of the stanchions by rolling

them on a surface plate or flat surface such as a

piece of plare glass, but it is not a simple operation

to straighten a bent tube, and a new part may be

necessary.

Check the stanchions for truth by rolling them

slowly on a flat checking table. A benr stanchion

may be realigned if the bow does not exceed $ in.

maximum. To realign the stanchion, a hand press

is required. Place the stanchion on two swage

"V" blocks at either end and apply pressure to

the raised portion of the stanchion. By means of

alternately pressing in this way and checking the

stanchion on a flat table the amount of bow can

be reduced until it is finally removed.

Having checked the stanchions for straightness and

reset as necessary, the top and bottom yokes can

now be checked. First, assemble the two stanchions

into the bottom yoke so that a straight edge across

the lower ends is toughing all four edges of the

tubes, then tighten the pinch bolts. Now view

them from the side; the two stanchions should be

quite parallel. Alternatively, the lower 12 in. of

the stanchions can be placed on a surface plate,

when there should be no rocking.

To reset, hold one stanchion in a vice (using soft

clamps) and reposition the other stanchion, using a

longer and larger diameter tube to obtain sufficient

leverage. Having checked the stanchions this way,

check the gap between them on the ground portion-

The next step is to place the top yoke in positioi

over the stanchions, when the steering stem should

be quite central.

The final step is to check if the tubes are parallel

when assembled into the top yoke only. ln this

case the bottom yoke can be fitted loosely on the

tubes, acting as a pilot only.

Though it is permissible to rectify slight errors in

alignment by resetting, it is much safer to replace

the part affected especially when there is excessive

misalign ent. Works reconditioned units are

available to owners in the United Kingdom through

the dealer network.

BOTH LEGS SHOULD

BE PARALLEL

Fig. E7. Fork leg alignment

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TELESCOPIC FORKS E

SECTION E5

HYDRAULIC DAMPING

Note the valve assembly which is retained in the

bottom of the fork leg. Bleed holes are contained

in the valve stem and in a sub-assembly at the toP of

the stem. This particular valve oPerates in conjunc-

tion with a damper valve which acts as a restrictor.

Oil is contained in the bottom member the level

of which is always above the valve assembly. On

compression the oil is forced through bleed holes

in the valve stem. As the travel increases the bleed

holes are progressively sealed off by a plastic sleeve

and the damping increases until finally the stanchion

is trapped on a cushion of oil which acts as the final

bump stop. During this operation a vacuum is

created in the space formed between the bottom of

the stanchion and the damper valve, hence oil is

transferred into this comPartment through the

eight bleed holes in the valve.

On expansion the oil in this newly formed comPart-

ment is compressed, the damper valve closes and the

oil is bled through four small holes in the damper

valve itself and then progressively through the holes

in the valve stem. While this oPeration is being

executed, oil is transferred back into the bottom

member in readiness for the next compression.

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SECTION F

WHEELS, BRAKES AND TYRES

INDEX

SECTION

F1 REMOVING AND RE-FITTING THE FRONT WHEEL

FzREMoVINGANDRE-FITTINGTHEFRoNTWHEELBEARINGS

F3STRIPPINGANDRE-ASSEMBLINGTHEFRoNTBRAKETWIN

LEADING SHOE TYPE (8" BRAKE)

F4 STRIPPING AND RE-ASSEMBLING THE FRONT BRAKE SINGLE

LEADING SHOE TYPE (6' BRAKE)

F5 STRIPPING AND REASSEMBLING REAR BRAKE

F6 REAR WHEEL REMOVAL AND REPLACEMENT

F7 REMOVING AND REPLACING REAR WHEEL BEARINGS

F8 BRAKE ADJUSTMENT

F9 REAR CHAIN ADIUSTMENT

F1O RENEWING BRAKE LININGS

F11 WHEEL BUILDING

F12 WHEEL BALANCING

F13 WHEEL ALIGNMENT

F14 BRAKING PER.FORMANCE DATA

F15 REMOVING AND REFITTING TYRES

F16 SECURITY BOLTS

F17 TYRE MAINTENANCE

F18 TYRE PRESSURES

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FWHEELS, BRAKES AND TYRES

SECTION FI

REMOVING AND REFITTING THE FRONT WHEEL

Place the machine with the front wheel approxi-

mately six inches off the ground. First, unscrew

the handlebar front brake adjuster then disconnecr

che cable at the actuating lever on the brake plate.

(See Section D18) Disconnect the torque arm at

the fork leg (6in. brake).

Unscrew the four wheel spindle cap nuts from the

base of each fork leg and remove the wheel.

Refitting the wheel is the reversal of the above

instructions. (Ensure that the peg on the brake plate

engages in the slot behind the fork on 8in. brake

models).

Tighten the spindle cap nuts evenly a turn at a

time.

Finally reconnect the front brake cable and adjust.

SECTION F2

REMOVING AND REFITTING

Remove the front wheel from the fork (see Section

above). Remove the retaining nut and withdraw the

front anchor plate from the brake drum. Unscrew

the retainer ring (left hand thread) using service

tool 61-3694.

The right bearing can be removed by using the

spindle and driving through from the left side.

Withdraw the inner grease retaining disc. To

remove the left bearing, spring out the circlip and

insert the spindle from the right side, driving the

bearing out complete with inner and outer grease

retainer plates.

Fully clean all parts in paraffin (kerosene). Clean

and dry the bearings thoroughly. Compressed air

THE FRONT WHEEL BEARINGS

should be used for drying out the ball races. Test

for end float and inspect the balls and races for

any signs of pitting. lf there is any doubt about

their condition, the bearings should be renewed.

To refit the bearings, first insert the left inner

grease retainer, bearing and outer dust cap, using

a liberal amount of grease (see Section A18). Refit

the spring circlip and insert the shouldered end

of the wheel spindle from the right, using it as a

drift to drive the bearing and grease retainer unril

they come up to the circlip. Re-insert the spindle

the opposite way round and refit the right hand

grease retainer disc. Drive the right bearing into

position well smeared with grease, then screw in the

retainer ring (left hand thread) until tight).

Fig. Fl. Exploded view of front wheel bearing arrangement (8 in. brake models)

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WHEELS, BRAKES AND TYRES

Finally, tap the spindle from

spindle shoulder up against

Access to the front brake shoes is gained by re-

moving the wheel (see Section Fl). The bral<e plate

is retained by a centre nut. This is recessed into

the anchor plate and will require the use of a thin

box spanner. The brake plate assembly will then

lift away complete. Pull the leading side of one shoe

away from the snail cam and lift it over towards the

other brake shoe.

Disconnect the springs and remove shoes. (See

Refer to Fig. F1 for correct layouts. Reassembly then

continues as a reversal of the above instructions.

Fig. F3).

Remove the brake shoe actuati ng pl u ngers from thei r

housings on the bral<e plate. Note the "O"-ring on

the tappets. Replace them if susPect. The cam and

lever assembly can now be removed from the

brake plate. The rubber "O"-ring on the spindle

should also be replaced if necessary. Note the

assembly of the snail cam adjuster and inspect for

wear on the teeth.

the left to bring the

the right bearing.

SECTION F3

STRIPPING AND REASSEMBLING THE FRONT BRAKE

TWIN LEADING SHOE TYPE (8in. BRAKE)

Fig.F2. Brake assembly details. 6 in' brake

Fig. F.3 Removing brake shoes-2LS condition

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FWHEELS, BRAKES AND TYRES

INSPECTION PR.OCEDURE

(1) Examine the anchor plate for cracks or dis-

tortion, particularly in the brake cam housing.

(2) Clean out the grease in the brake cam spindle

and remove any rust with a fine emery cloth.

(3) lnspect the return springs for signs of fatigue

and distortion. Renew them if necessary.

(4) Examine the brake drum for scoring or ovality.

ln the case of the rear wheel if the drum

requires skimming it sh ould be removed from

the wheel. Do not skim more than .010in. from

the drum. lf the diameter exceeds more than

given in the GENERAL DATA by more han

.01 0 in. the d rum should be renewed.

ln the case of the front wheel drum, scoring or

signs of ovality can be ermoved by sir-nilar

proced u re.

(5) Examine the bral<e shoes. The bralce linings

should be replaced immediately the rivets show

signs of having worn level with the linings face,

or the linings show signs of cracks or uneven

wear. Also check that the bral<e shoes are not

cracked or distorted in any way.

To reassemble the shoes, first grease the cam and

the actuating plunger and then assemble them into

the brake plate. Assemble the springs onto the

brake shoes (as shown in fig. F4) and holding the

shoes apart rest them onto the brake plate with the

snail cam adjusters in position. Then force the shoes

apart and into their respective locations.

Fig. F4. 2LS brake XT:fr:'j. showing position

While replacing the shoes the anchor plate can be

effectively supported by gripping a spindle of suit-

able size in a vice and placing the plate onto it (see

fig. F3).

The complete brake plate is now ready for fitting

to the wheel. Replace the anchor plate over the

wheel spindle and lock it home with the spindle

n ut.

Finally, refit the wheel and adjust the brake (see

Sections Fl and F8).

SECTION F4

STRIPPING AND REASSEMBLING THE FRONT BRAKE

SINGLE LEADING SHOE TYPE (5in. Brake)

Access to the brake shoes is obtained by removing

the wheel and unscrewing the central nut which

retains the brake anchor plate. lfthe brake operating

lever is then turned to relieve the pressure of the

shoes against the drum, the complete brake plate

assembly can be withdrawn from the spindle.

Remove the brake shoes by lifting one brake shoe

away from the brake plate until the return spring

becomes disconnected.

Fig. F5. Reassembling brake shoes (6in. brake)

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WHEELS, BRAKES AND TYRES

Fig. F6. Correct assembly of brake shoes onto front

anchor Plate.

To re-assemble the brake shoes to the brake

anchor plat,e first place the two bralce shoes

on the bench in their relative positions" Fit

the return springs to the retaining hooks,

then taking a shoe in each hand (see Fig' F5)

and at the same time holding the springs in

tension, position the shoes as shown over the

cam and fulcrum pin and snap down into Position

by pressing on the outer edges ofthe shoes.

Note. When replacing the brake shoes, note

that the leading and trailing brake shoes are

not interchangeable in either the front or

rear brake and ensure that they are in their

correct relative Positions as shown in Fig. F6.

Re-assembly then continues by placing the

anchor plate over the wheel spindle and

locking it with the spindle nut. Refer to

Section F1 3 for final re-alignment of the wheel

ifthis is found to be necessarY'

The front brake has fully floating adlusters and

therefore the shoes are automatically self centra-

lising.

The adjustment of the front brake operating

mechanism is by means of a knurled adjuster nut

incorporated in the handlebar abutment' Turn

the nut anti-clockwise to take up the slack in the

control cable. The correct adjustment is with not

less than ft in. (1 '5 mm.) and not more than * in'

(3 mm.) slack in the inner cable at the handlebar

lever.

Adjustment of the rear brake is achieved by the

wing nut on the rear end ofthe brake operating rod'

Turn the nut clockwise to reduce clearance' From

the static Position before the brake is applied there

should be about |in. (1 '2 cm') of free movement

before the brake starts to oPerate'

SECTION F5

STRIPPING AND REASSEMBLING REAR BRAKE

Access to the rear brake shoes is gained by removing

the rear wheel (see section F6). Remove the brake

plate and remove the shoes as described in Section

F4.

Reassemble as described in Section F4'

The rear brake has a fully floating cam and therefore

the shoes are automatically self centralising'

SECTION F6

REAR WHEEL REMOVAL AND REPLACEMENT

Support the machine on a suitable stand so that

the rear wheel is approximately 17in' clear of the

ground. Uncouple the rear chain at its sPring link

"nd remove it from the rear wheel sprocket' Leave

the chain in position on the gearboxsprocket; this

*'if much simplify replacement' Unscrew and

;;;."; the rear biake iod ad;uster' Push the rod

clear of the brake lever'

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FWHEELS, BRAKES AND TYRES

Disconnect the speedometer drive cable at the drive

gearbox at the right side of the rear wheel. Remove

the left side pillion footrest; this will release the

brake torgue arm. Remove the wheel spindle nut

from the right side and while supporting the wheel

with one arm withdraw the spindle from the left

side with the aid of a tommy bar. The wheel can

now be removed.

SECTION F7

REMOVING AND REPLACING REAR WHEEL BEARINGS

The hub is fitted with two identical single row ball

bearings which are a press fit into the hub.

Remove the speedometer drive ring (left hand

thread) from the right side and the bearing retaining

ring (right hand thread) from the left side. Use

service tool No. 61-3694 to remove bearing

retai n e r.

Using a drift (of the dimensions shown in fig. F7)

knock out the spacer tube contained between the

bearings taking one bearing with it. This operation

can be carried out from either side of the wheel.

See fig. F8.

1--.- 2

Fig F7. Wheel bearing drift

lf a drift of the correct dimensions is not used then

the spacer tube will be damaged and have to be

replaced.

The bearing is an interference fit on the spacer tube

and should be removed using the same drift as

before. The spacer tube and drift can now be used

to knock the remaining bearing out of the hub.

Remove the bearing from the spacer tube.

To examine the bearings, wash thoroughly in para-

ffin and if possible, blow out with a high pressure air

line. Examine each bearing carefully for signs of

roughness indicating broken balls or damaged

tracks, or excessive play.

Fig. F8. Drifting the wheel bearings

The grease retainers behind the bearings should

not require attention. But if replacement is neces-

sary knocl< them out using a drift from inside the

hub.

Replace the bearing onto the spacer tube and place

the assembly into the hub from the left side. Drift

the bearing into the housing and down onto the

grease retainer with a suitable diameter drift.

Force must be applied to the outer ring of the

bearing and not the inner ring. lf possible use a hand

press for replacing these bearings.

Replace the retaining ring and tighten using tool

No. 61-3694. Replace the remaining bearing from

the right side.

Reassembly of the hub is simply the reverse of the

dismantling procedure but, when pressing the

oearings in, apply pressure only to the outside ring

ofthe bearing and ensure that the retainer on the

left-hand side is quite tight.

oi(J -'

lr.l

| -uoo

lEiS..^>."

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WHEELS, BRAKES AND TYRES F

Fig. F.9. Exploded view of rear wheel assembly

SECTION F8

BRAKE ADJ USTMENT

The brakes must be adjusted to give maximum

efficiency at all times and for this to be maintained,

the shoes should be iust clear ofthe drum when the

brake is off, and close enough for immediate contact

when the brake is applied. The brakes must not be

adjusted so closely, however, that they are in

continual contact with the drum; excessive heat

may be generated, resulting in deterioration of

braking efticiency.

On twin leadlng shoe brakes the expansion of the

shoes is equalised by the caliper action of the cam

levers. The cable adjuster is combined with the

control lever on the handlebar and should be set

to eliminate slackness without applying the brakes.

After considerable mileage it may be necessary to

re-position the shoes within the brake drum.

lndividual adjustment of the shoes is provided by a

screw at the actuating taPPet of each screw. Slacken

off the cable adjuster at the handlebar lever and

remove the rubber Srommet from the hub shell.

Rotate the wheel until the aPerture is opposite to

the adjuster screw. The adluster turns with a series

of clicks and must be rotated in a clocl<wise direction

until it cannot be turned any further. At this point

the shoes will be fully expanded against the drum.

Now unscrew the adjustor until the wheel is free to

rotate and the shoe is just clear of the drum. Turn

the wheel through half a revolution and rePeat the

adjustment on the remaining shoe. Check that the

wheel revolves freely. Now adiust the clearance in

the cable at the adjuster on the control lever. Turn

the knurled nut until there is aPProximately Sin.

to {in. slack in the cable at the lever.

On sJngle leading shoe front brakes the adjustment

is taken up at the handlebar lever as for the twin

leading shoe brake. Note: The brakes are not

adjustable within the drum on this brake. When the

range ofadiustment has been reduced at the handle-

bar lever drive to where the cable can be adjusted

by means of an integral ad.iuster situated ,iust below

the stop light switch.

The rear bralce is adjusted by turning the self-

locking sleeve in a clockwise direction (viewed from

the rear of the machine), to shorten the effective

length of the brake rod and so oPen the shoes in

the drum.

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WHEELS, BRAKES AND TYRES

Note that if maximum efficiency is to be obtained,

the angle between the brake cable or rod and the

operating lever on the brake plate should not

exceed 90" when the brake is fully applied.

On single leading shoe brakes. When new front

brake shoes have been fitted or if, during dis-

mantling of the front wheel, the fulcrum pin was

disturbed, the shoes must be centralized within

the drum. To do this, slacl<en the fulcrum pin nut

and operate the brake cam so as to open the brake

shoes. The fulcrum pin will then position itself in

the housing until both shoes are pressing equally

on to the drum. Tighten the fulcrum pin nut firmly

and release the brake.

The rear brake shoes are of the fully-floating type

(i.e., they are not pivoted on a fulcrum) and are

therefore self-central izi ng.

SECTION F9

REAR CHAIh{

The rear chain must be adjusted when the wheel is

at its lowest point of suspension travel. Support the

machine with the rear wheel clear of the ground and

rotate the wheel slowly until the tightest point on

the chain is found, then check it's up and down

movement in the centre ofthe chain run. The total

movement should be 1$in. and if it varies from this

setting, then the chain must be adiusted by altering

the position of the swinging arm.

The rear brake stop light must be allowed to swing

clear of the left side cam plate. This is easily done

by removing the rearmost bolt and allowing the

switch assembly to swing in a clockwise direction.

(Note the assembly of spacer and washers for this

bolt.)

Slacken the large nut on the right side of the swing-

ing arm spindle sufficiently to allow the cam plates

at each end of the spindle to come away from their

retaining dowels. (The spindle will need to be

tapped from the right side to achieve this condition.)

It is not necessary to loosen the torque stay nuts

but the brake rod adjuster must be slackened offto

allow for movement.

ADJ USTMENT

Fig. Fl0. Rear chain adiusting plates

The cam plates at both ends of the swinging arm

spindle can now be rotated clockwise or anti-

clockwise to make the adjustment. They must be

placed in the same relative position on their respec-

give dowels (see fig. F10).

The nut on the swinging arm spindle can now be

fully retightened.

SECTION F IO

RENEWTNG BRAKE LtNtNGS (REAR BRAKE)

(AND STNGLE LEADTNG SHOE FRONT BRAKE)

Hold the shoe firmly in a vice and, using a good sharp

chisel, cut off the peened-over portion of the rivet

as shown below.

Drive out the rivets with a suitable pin punch and

discard the old lining. Reverse the shoe in the vice

and draw-file the face of the shoe to remove any

bu rrs.

Clamp the new lining tightly over the shoes and,

using the shoe holes as a jig, drill straight through

the lining with a $ in. diameter drill.

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WHEELS, BRAKES AND TYRES F

Remove the clamps and, holding the lining carefully

in the vice, counterbore or countersink (according

to the type of rivet used) each hole to no more than

two-thirds the thickness of the lining, i.e., if the

lining is 1f in. thick, then the counterbore must

not be deeper than I in.

Having prepared the linings for riveting, start at the

centre and position the iining with one or more

rivets.

Place a suitable mandrel in the vice, clamp the

linings ro the shoes with either small "G" or

toolmakers clamps and peen-over the rivets as

shown in Fig. F12, working alternatively outwards

from the centre.

The mandrel used in the vice musc be flat on the

end and the diameter should be no more than that

of the rivet head. lt will also help to bed the rivet

down if a hollow punch is used before peening.

Fig. Fll. Chiselling off brake rivets

Fig, F12. Punching lining rivets

Note. lf the clamps are used correctly, that is,

next to the rivet being worked on, the Iinings can

be fitted tightly to the shoe.

lf the linings are fitted incorrectly, a gap will occur

between the lining and the shoe, resulting in

inefficient and "spongy" braking.

When the riveting is completed, file a good chamfer

at each end of the lining to aPProximately half its

depth and lightly draw-file the face of the Iining to

remove any fraze caused by the drilling.

BUILDI NG

lf tension has been lost there will be no ringing tone

and the spokes will move freely across each other'

When a spoke needs tensioning, the nipple through

the rim must be screwed further on to the sPoke

but at the same time, the truth of the wheel must be

checked and it may be necessary to ease the tension

at another part of the wheel in order to maintain its

t ruth.

It will therefore be obvious that spoke replacement,

spoke tensioning or wheel truing are not oPerations

to be treated lightly.

SECTION F I I

\MHEEL

This is a job which is best left to the sPecialist as it

is essential that the wheel is laced correctly and

that when truing, the spokes are correctly tensioned'

It is however, possible for the less experienced to

avoid trouble by periodically examining the wheels.

As spokes and nipples bed down the tension will be

lost and unless this is corrected the spokes will

chafe and ultimately break.

Periodically test the tension either by "ringing",

that is striking with a metal tool or by placing the

fingers and thumb of one hand over two spokes at

a time and pressing them together.

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FWHEELS, BRAKES AND TYRES

Careful examination of the wheel will show that

for every spoke there is another pulling in the

opposite direction and that the adjacent spoke goes

to the opposite side of the hub.

Increasing the tension tends to pull the rim so, to

counteract this, it is sometimes necessary to increase

the tension on the spoke or spokes either side to

maintain the truth of the wheel.

With a little care and patience it is possible for the

unskilled to at least re-tension the spokes but, turn

each nipple only a little at a time as, once the spoke

is under tension only a fraction of a turn is some-

times sufticient to throw the rim badly out of truth.

SECTION FIz

\^/HEEL BALANCING

When a wheel is out of balance it means that there is

more weight in one part than in another. This is

very often due to variation in the tyre and at

moderate speeds will not be noticed but at high

speeds it can be very serious, particularly if the

front wheel is affected.

Wheel balancing can be achieved by fitting standard

one ounce and half ounce weights which are readily

available, as required. Allfront wheels are balanced

complete with tyre and tube before leaving the

factory and if for any reason the tyre is removed it

should be replaced with the white balancing "spot"

level with the valve. lf a new tyre is fitred, existing

weights should be removed and the wheel re-

balanced, adding weights as necessary until it will

remain in any position at rear. Make sure that the

brake is not binding while the balancing operation

is being carried out.

For normal road use it is not found necessary for the

rear wheel to be balanced in this way.

SECTION F 13

WHEEL ALIGN MENT

Due to the design of the swinging arm and rear

wheel arrangement the alignment of the wheels

cannot be adjusted.

Assuming that the machine has not suffered any

damage the wheels will automatically remain in line.

lf however, alignment is suspect for any reason, it

can easily be checked. Use a straight edge ofsteel or

wood the length of which should be as in fig. F1 3.

Lay the straight edge on two blocks on one side of

the machine.

lf the tyres are the same size and

alignment the straight edge will be

tyre at four points.

lf the front tyre is of smaller section

be as in fig. F13.

F10

the wheels in

touching the

then it should

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WHEE!-S, BRAKES AND TYRES F

SECTION FI4

BRAKING PERFORMANCE DATA

The following information is in accordance with the requirements of

the U.S. Federal Highway Administration, DePartment of Trans-

portation.

This figure indicates passing times and distances that can be met or exceeded

by the vehicles to which it applies, in the situations diagrammed below.

The low-speed pass assumes an initial speed of 20 m.p.h. and a limiting

speed of 35 m.p.h. The high-speed pass assumes an initial speed of 50 m.p.h.

and a limiting speed of 80 m.p.h.

Notice:-The information presented represents results obtainable by skilled

drivers under controlled road and vehicle conditions, and the information may

not be correct under other conditions.

LOW-SPEED

INITIAL SPEED:

20 MPH LIMITING SPEED:35 MPH

I rorAl PAsstNc DIsTANCE,FEET j

f - TorAL PASSING TlME,sEcoNDS I

. I -, r I

--'7] 4oi I 4o'l 'I

_'--------.-l*l

r [---Jm- -------.] l-a

I I LU coNSTANT 20 MPH

I ss'rRuct<

HIGH-SPEED

INITIAL SPEED

50 MPH LIMITING SPEED:80 MPH

TOTAL PASSING DISTANCE, FEET

TOTAL PASSING TIME.SECONDS

55lTRUCK

This figure indicates braking performance that can be met or exceeded by the

vehicles to which it applies, without locking the wheels, under different condi-

tions of loading.

The information presented represents results obtainable by skilled drivers

under controlled road and vehicle conditions, and the information may not be

correct under other conditions.

Description of vehicles to which this table applies:-

TRIUMPH T25T TRAIL BLAZER

A. Fully Operational

Service Brake

LOAD

LIGHT 154

MAXIMUM _1 60

rl,o zJo sJo alo

Stopping distance in feet from 50 m.p.h.

Description of vehicles to whkh .l;Ui?" applies:-

Summary Table

LOW-SPEED PASS 396 feet; 8'6 seconds

HIGH-SPEED PASS 1384 feet: 15'3 seconds

CONSTANT 50 MPH

F11

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FWHEELS, BRAKES AND TYRES

The following information is in accordance with the requirements of

the U.S. Federal Highway Administration, Department of Trans-

portation.

This figure indicates braking performance that can be met or exceeded by the

vehicles to which it applies, without locking the wheels, under different condi-

tions of loading.

The information presented represents results obtainable by skilled drivers

under controlled road and vehicle conditions, and the information may not be

correct under other conditions.

Description of vehicles to which this table applies:-

TRIUMPH TS25S BLAZER SS

A. Fully Operational

Service Brake

LOAD

LIGHT

--154

MAXIMUM _160

200 300 400

Stopping distance in feet from 60 m.p.h.

This figure indicates passing times and distances that can be met or exceeded

by the vehicles to which it applies, in the situations diagrammed below.

The low-speed pass assumes an initial speed of 20 m.p.h. and a limiting

speed of 35 m.p.h. The high-speed pass assumes an initial speed of 50 m.p.h.

and a limiting speed of 80 m.p.h.

Notice:-The information presented represents results obtainable by skilled

drivers under controlled road and vehicle conditions, and the information may

not be correct under other conditions.

Description of vehicles to which this table applies:-

AS ABOVE

Summary Table

LOW-SPEED PASS 396 feet; 8.6 seconds

HIGH-SPEED PASS 1384 feet;15.3 seconds

LOW-SPEED

INITIAL SPEED:

20 MPH LIMITING SPEED:3s MPH

I TOTAL PASSING DISTANCE,FEET ,

I rornl PASSING TlME,sEcoNDS I

*"^t-__----- - -----dl

*-n4oi t4o'l'j

k--t F- - i

I l--tn -----J-l-a

I I Lil CONSTANT 20 MPH I f!

lss'rRrrcK

HIGH-SPEED

INITIAL SPEED:

50 MPH LIMITING SPEED:80 MPH

TOTAL PASSING DISTANCE, FEET

TOTAL PASSING TIME.SECONDS

55:TRUCK

F12

CONSTANT 50 MPH

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WHEELS, BRAKES AND TYRES F

SECTION F 15

REMOVING AND

To remove the tyre first remove the valve cap and

valve core, using the valve cap itself to unscrew the

core. Unscrew the knurled valve securing nut and

then place all parts where they will be free from

dirt and grit. lt is recommended that the cover

beads are lubricated with a little soaPy water before

attempting to remove the tyre. The tyre lever

should be dipped in this solution before each

REFITTING TYRES

second lever. Continue round the bead in steps of

two to three inches until the bead is completely

away from the rim. Push the valve out of the rim

and then withdraw the inner tube. To completely

remove the tyre first stand the wheel upright and

then insert a lever between the remaining bead

and the rim. The tyre should be easily removed

from the rim as shown in Fig. Fl 5.

Fig. F14. Removing the first bead of the tyre-Lever

inserted close to valve whilst bead is pressed into well

on opposite side of wheel

applicaticn. First, insert a lever at the valve Posi-

tion and whilst carefully pulling on this lever, press

the tyre bead into the well of the rim diametrally

opposite the valve position (see Fig. F14). lnsert a

second lever close to the first and prise the bead

over the rim flange. Remove the first lever and

reinsert a little further round the rim from the

Fig. Fl5, Removing the first bead

two tyre levers

Fig. Fl6. Cover and tube assembled ready for refitting

- to the wheel

REFITTING THE TYRE

First place the rubber rim band into the well of the

rim and mal<e sure that the rough side of the rubber

band is fitted against the rim and that the band is

central in the well. Replace the valve core and

inflate the inner tube sufficiently to round it out

without stretch, dust it with french chall< and insert

it into the cover with the valve located at the white

"balancing spot" leaving it protruding outside the

beads for about four inches either side of the valve.

Fig. F17. Refitting the tyre to the wheel, Note valve

engaged in rim hole

of the tyre, using

F13

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FWHEELS, BRAKES AND TYRES

At this stage it is advisable to lubricate the beads

and levers with soapy water (see Fig. F1 6).

Squeeze the beads together at the valve position

to prevent the tube from slipping bacl< inside the

tyre and offer the cover to the rim, as shown in

Fig. Fl8. Levering the first bead onto the rim

Fig. F17, at the same time threading the valve

through the valve holes in the rim band and rim.

Allow the first bead to go into the well of the rim

and the other bead to lie above the level of the

rim flange.

Working from the valve, press the first bead over

the rim flange by hand, moving forward in small

steps and making sure that the part of the bead

already dealt with, Iies in the well of the rim. lf

necessary use a tyre lever for the last few inches,

as shown in Fig. F18. During this operation con-

tinually check that the inner tube is not trapped by

the cover bead.

Fig. F19. Refitting the second bead over the wheel

rim. Care must be taken not to trap inner tube

Press the second bead into the well of the rim

diametrally opposite the valve. lnsert a lever as

close as possible to the point where the bead passes

over the flange and lever the bead into the flange,

at the same time pressing the fitted part ofthe bead

into the well of the rim. Repeat until the bead is

completely over the flange, finishing ar the valve

position (see Fig. F19).

Push the valve inwards to ensure that the tube

near the valve is not trapped under the bead.

Pull the valve back and inflate the ryre. Check that

the fitting line on the cover is concentric wirh the

top of the rim flange and that the valve prorrudes

squarely through the valve hole. Fit the knurled

rlm nut and valve cap. The tyre pressure should

then be set to the figure given in General Data.

SECTION FI6

SECURITY

Security bolts are fitted to the rear wheel to prevent

the tyre "creeping" on the rim when it is subjected

to excessive acceleration or braking. Such move-

ment would ultimately result in the valve being torn

from the inner tube. There are two security bolts

fitted to the rear wheel, which are equally spaced

either side of the valve and thereby do not affect

the balance of the wheel.

Note. The security bolt nuts must not be over-

tightened, otherwise excessive distortion may

occu r.

tl4

BOLTS

Where a security bolt is fitted the basic procedure

for fitting and removing the tyre is the same, but

the following instruction should be followed:-

(1) Remove the valve cap and core as described.

(2) Unscrew the security bolt nut and push the

bolt inside the cover.

(3) Remove the first bead as described.

(4) Remove the security bolt from rhe rim.

(5) Remove the inner rube as described.

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wHEELS, BRAKES AND TYRES

(6) Remove the second bead and tYre.

For refitting the tyre and inner tube:-

(1) Fit the rim band.

(2) Fit the first bead to the rim without the inner

tube inside.

(3) Assemble the security bolt into the rim, Putting

the nutontothe first fewthreads (see Fig. F20).

Fig. F20. Placing the security bolt in position

(4) Partly inflate the inner tube and fit it into the

ty re.

(5) Fit the second bead but keep the security bolt

pressed well into the tyre, as shown in Fig. F21 '

and ensure that the inner tube does not

become trapped at the edges'

(6) Fit the valve stem nut and inflate the tyre.

(7) Bounce the wheel several times at the Point

where the secu rity bolt is fitted and then

tighten the security bolt nut.

Fie. F2l. Refitting the second bead with the security

bolt in position

(4) Regular checks should be made for flints, nails,

small stones etc., which should be removed

from the tread or they may ultimately Penetrate

and damage the casing and Puncture the tube.

(5) Tyres and spokes should be kept free of oil,

grease and paraffin. Regular cleaning should be

carried out with a cloth and a little petrol

(gasoline).

(6) lf tyres develope irregular wear, this may be

corrected by reversing the tyre to reverse its

direction of rotation.

(7) lf a sidecar is fitted then correct alignment

should be maintained. The method for testinS

sidecar alignment is given in Section F14.

Before inflating, check that the fitting line on

the tyre wall just above the bead on each side

is concentric with the rim.

SECTION FI7

TYRE MAINTENANCE

To obtain optimum tyre mileage and to eliminate

irregular wear on the tyres it is essential that the

recommendations governing tyre pressures and

general maintenance are followed. The following

points are laid out with this in mind'

(1) Maintain the correct inflation Pressure as

shown in "General Data". Use a Pressure

gauge frequently. lt is advisable to check

and restore tyre Pressures at least once Per

week. Pressure should always be checl<ed when

tyres are cold and not when they have reached

normal running temPeratures.

(2) When a pillion Passenger or additional load is

carried, the rear tyre Pressure should be

increased appropriately to cater for the extra

load.

(3) Unnecessary rapid acceleration and fierce

braking should always be avoided. This treat-

ment invariably results in rapid tyre wear.

F15

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FWHEELS, BRAKES AND TYRES

lf necessary bounce the wheel to help seat the tyre

but, see that there is adeguate pressure to prevent

damaging the tyre or tube and only use moderate

force. lf the tyre will not seat, it is better to release

the pressure, apply soap solution to lubricate and

re-i nflate.

lnflate to the required pressure and check fitting

lines again. lnflation should not be too rapid,

particularly at the commencement, to allow the

beads to seat correctly on the rim.

See that the valve protrudes squarely through the

valve hole before screwing down the knurled nut

and finally, replace the dust cap.

Front

lnflation pressure (lb. per sq. in.)

16 18 20 24 28 32

Load per tyre (lb.)

200 230 260 320 380 440

Rear 280 310 335 390 450 500

SECTION FI8

TYRE PRESSURES

The recommended inflation pressures of 22 p.s.i.

(front tyre) and 24 p.s.i. (rear tyre) are based on a

riders'weightof 1401b. lf the riders'weight exceeds

140 lb. the tyre pressure should be increased as

follows:-

Front Tyre

Add 1 lb. per square inch for every 28 lb. in excess

of140 lb.

Rear Tyre

Add 1 lb. per sguare inch for every 14|b. in excess

of140 lb.

It is further recommended that when carrying a

pillion passenger or eguipmenr giving additional

weight, the inflation pressures should be increased

in relation to the actual load on each tyre, as

indicated in the chart below. To find the load on

each tyre, place the front and rear wheel in turn,

on to a weighbridge. The reading should be taken

when the rider is seated on the machine together

with the additional weights.

F16

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SECTION G

ELECTRICAL

INDEX

SECTION

DESCRIPTION

G1 ALTERNATOR

G2 BATTERY INSPECTION AND MAINTENANCE

G3 COIL IGNITION SYSTEM

G4 SPARKING PLUG

G5 CHARGING SYSTEM

G6 ZENER DIODE CHARGE CONTROL

G7 ELECTRIC HORN

G8 TAIL AND STOP LAMP UNIT

G9 ALTERNATOR_ADDITIONAL INFORMATION

G1O DIRECTION INDICATOR LAMPS

G11 IGNITION SWITCH

G1Z OTHER LIGHT UNITS

G13 HEADLAMP

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GELECTRICAL SYSTEM

The electrical system is supplied from an A.C.

generator contained in the primary chaincase and

driven directly from the crankshaft.

A Zener-Diode is connected in circuit to regulate

the battery charging current and consequently

prevent over-chargi ng.

The ignition system is controlled by a contact

breaker mechanism driven by the camshaft.

Routine maintenance required by the various com-

ponents is detailed in the following sections. Whilst

checking the electrical system, opportunity should

be taken to ensure that all wiring connections and

frame earthing points are clean and secure.

DESCRIPTION

A capacitor (model 2MC) is integrated in the circuit

on all models and when the battery earth lead

(+VC) is disconnected the machine will continue

to function quite normally.

All electrical components except the battery,

lamps, horn and handlebar switches are housed in a

rubber mounted electrical box situated beneath the

fuel tank. The various items within the box are

shown in fig. G1, and it should be noted that the lid

of the aluminium box serves as the Zener Diode

heat si n k.

See Section D12 for detai ls regard i ng the d ismantl i ng

procedure for the electrical box.

1 IGNITION COtL

2 IGNITION SWITCH

3 CAPACTTOR (2MC)

4 CONDENSER

5 FLASHER UNIT

6 HORN

7 ZENER DIODE,J

8 RECTIFIER

9 ELECTRICAL BOX

MOUNTINGS FOR

LATER MODELS

Fig. Gl. Electrical box components

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ELECTRICAL SYSTEM G

SECTION G I

ALTERNATOR

The alternator consists of a spigot-mounted 6-coil

laminated encapsulated stator with a rotor carried

on and driven by an extension of the crankshaft.

The rotor has an hexagonal steel core, each face of

which carries a high-energy Permanent magnet

keyed to a laminated pole tip. The pole tiPs are

riveted circumferentially to aluminium side plates,

the assembly being cast in aluminium and machined

to give a smooth external finish.

DESCRIPTION

The container for the model PUZ5A battery is

moulded in transparent material through which the

acid can be seen. The tops ofthe containers are so

designed that when the covers are in position, the

special anti-spill filler plugs are sealed in a common

venting chamber. Gas from the filler plugs leaves

this chamber through a vent pipe. Polythene tubing

may be attached to the vent PiPe to lead the

corrosive fumes away from any Parts of the machine

where they might cause damage.

PART A

CHARGING THE BATTERY

Whilst the battery leaves the factory in the fully

"dry-charged" condition, it may slowly lose some

charge in storage. ln view of this, the following

filling instructions must be carefully observed:-

SECTION G2

BATTERY !NSPECTION AND MAINTENANCE

There are no rotating windings, commutator, brush-

gear, bearings or oil seals and consequently the

alternator requires no maintenance aPart from

checking occasionally that the snaP connectors in

the output cables are clean and tight.

lf rotor removal is necessary, there is no need to

fit magnetic keepers to the rotor poles. When

removed, wipe off any swarf which may have been

attracted to the pole tips and put the rotor in a

clean place until required for refitting.

With the acid, battery and room temPerature

between 60'F., and 100'F. (1 5.5/37.7'C.), remove the

vent plugs and fill each cell to the coloured marker

line.

Measure the temperature and specific gravity of the

electrolyte in each of the cells.

Allow to stand for 20 minutes and then re-check

the tem peratu re and specifi c gravity of the electrolyte

in each cell.

The battery is then ready for service unless the

above checl<s show the electrclyte temPerature to

have risen by more than 10'F. (5.5'C.) or the

specific gravity to have fallen by more than 10

'points", i.e., by more than 0.01 0 specific gravity.

ln this event, it will be necessary to recharge the

battery at the appropriate charge rate (0'7 amperes)

until the specific gravity values remain constant for

three successive hourly readings and all cells are

gassing freely.

During charging, keep the electrolyte in each cell

level with the coloured marker line by adding

distilled water-not acid.

PART B

ROUTINE MAINTENANCE

Every 1,000 miles (1 ,600 km.) or monthly, or more

regularly in hot climates the battery should be

cleaned as follows:-

Fig. G2. The PUZ5A batterY

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GELECTRICAL SYSTEM

Remove the battery cover and clean the battery top.

Examine the terminals: if they are corroded scrape

them clean and smear them with a film of petroleum

jelly, or with a silicone grease.

The level of the electrolyte in each cell should be

checked weekly or every 250 miles. Lift the battery

out of the carrier so that the coloured filling line

can be seen. Add distilled water untilthe electrolyte

level reaches this line.

Note. On no account should the battery be

topped-up above the coloured line.

With this type of battery, the acid can only be

reached by a miniature hydrometer, which would

indicate the state of charge.

Great care should be taken when carrying out these

operations not to spill any acid or allow a naked

flame near the electrolyte. The mixture of oxygen

and hydrogen given off by a battery on charge, and

to a lesser extent when standing idle, can be

dangerously explosive.

The readings obtained from the battery electrolyte

should be compared with those given in the table

ooposite. lf a battery is suspected to be faulty it is

advisable to have it checked by a Lucas depot or

agent.

A lead-acid battery slowly loses its charge whilst

standing-the rate of loss being greater in hot

climates. lf a battery is not being used, it is important

to give it freshening charges at the appropriate

recharge rate. These should be given fortnightly in

temperate climates and weekly in the tropics.

PART C

SPECIFIC GRAVITY OF ELECTROLYTE

FOR FILLING THE BATTERY

To obtain a specific gravity strength of 1.260 at

60"F. (15.5'C.), add one part by volume of '1.840

specific gravity acid to 3.2 parts of distilled water.

To obtain a specific gravity strength of 1.210 at

60"F. (15.5'C.), add one part by volume of 1.840

specific gravity acid to 4.3 parts of distilled water.

PART D

MAXIMUM PERMISSIBLE ELECTROLYTE

TEMPERATURE DURING CHARGE

Climates normally I Climates frequently

below I above

80'F. (26.6'C ) I 80'F. (25.5'C.)

100"F. (38'C ) I 120"F. (49'C.)

Note. The specific gravity of the electrolyte

varies with the temperature. For convenience in

comparing specific gravities, they are always

corrected to 60'F., which is adopted as a reference

temperature. The method of correction is as

follows:-

For every 5"F. below 50'F. deduct .002 from the

observed reading to obtain the true specific gravity

at 60'F. For every 5'F. above 60"F., add .002 to the

observed reading to obtain the true specific

gravity at 60"F.

The temperature must be indicated by a thermo-

meter having its bulb actually immersed in the

electrolyte and not the ambient temperature. To

take a temperature reading tilt the battery sideways

and then insert the thermometer.

PART E

CHECKING D.C. INPUT TO BATTERY

(a) Connect D.C. ammeter in main battery line

(between battery negative terminal and battery

cable). Red lead to casle, black lead to battery

te rm i nal.

(b) Disconnect the Zener Diode. (Remove both the

brown/blue cables from the 2MC capacitor.)

3000 rev./min. Operate lighting switch.

U.K. and climates

normally below

80'F. (25.6"C.)

Tropical climates

over

80'F. (26.6"C.)

Filling Fully charged Filling Fully charged

1.260 1.270-1.290 1.210 1.210-1.230

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ELECTRICAL SYSTEM G

Lighting

switch

position

MINIMUM CURRENT READING

Two lead stator

OFF 4.5 A

H/lamp

M/beam

1.0 A

coNcLUsloNs

If the above or higher readings are obtained the

battery is in good condition.

lf the readings are lower, test the alternator.

PART B

FAULT F!NDING IN THE

LOW-TENSION CIRCUIT

To checl< whether there is a fault in the low tension

circuit and to locate its Position, the following tests

should be carried out.

First inspect the in-line fuse situated in the battery

Brown/Blue lead and replace if suspect: check also

the cut-out switch; this can be done by disconnect-

ing the White and White and Yellow leads from the

right handlebar switch and connect together, this

will complete the ignition circuit by passing the

cut-out switch.

Connect a 0-1 5 volt D.C. voltmeter, with the black

leaC to the "CB" or "+ " terminal of the coil and

the red lead to earth. Turn the engine until the

contacts open. With the ignition switched on, the

voltmeter should read battery voltage. No reading

indicates an oPen circuit ignition switch, coil primary

winding or a short circuit across the contacts which

can be confirmed by disconnecting the coil/contact

breaker lead at the coil. lf battery voltage is then

indicated by the voltmeter the fault lies in the con-

tacts or the circuitry from the coil to them. This

fault is very often caused by incorrect assembly of

the contact insulating washers.

Turn the engine until the contacts close and the

voltmeter should then read zero. Any reading

indicates the contacts are either burnt or dirty and

should be cleaned or stoned flat.

Connect the voltmeter with the red lead to earth

and the black lead to the "SW" or "-" terminal of

the coil. Ensure the contacts are closed and switch

on the ignition switch. Take careful note of the

SECTION G3

COIL IGNITION SYSTEM

DESCRIPTION

The coil ignition system comprises an ignition coil,

mounted in the electrical box and a contact

breaker unit fitted in the timing cover. Apart from

cleaning in-between the terminals, and checking

the connections for soundness, the coil will not

require any other attention. Testing the ignition

coil is amply covered in Part "C", page G6'

whilst testing the contact breaker is detailed in

Part "D".

The best method of approach to a faulty ignition

system is to first check the low-tension circuit for

continuity as shown in Part "A", then follow the

procedure laid out in Part "B" to locate the fault(s).

Failure to rocate a fault in the low-tension circuit

indicates that the high-tension circuit or sparking

plug is faulty, and the procedure detailed in Part "E"

must be adopted. Before commencing any of the

following tests, however, the contact breaker the

sparking plug gaps must be cleaned and adjusted

and the battery connections checked to eliminate

these possible sources of faults.

PART A

CHECKING THE LOW-TENSION

FOR CONTINUITY

To check whether there is a fault in the low-tension

circuit and to locate its Position, the following tests

should be carried out:-

First inspect the in-line fuse in the battery earth

cable (brown/blue lead) and replace if suspect.

Check also the cut-out switch; this can be done by

disconnecting the white, and white/yellow lead

from the right handlebar switch and connecting

them together. This will complete the ignition cir-

cuit by by-passing the cut-out switch.

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GELECTRICAL SYSTEM

voltmeter reading then quicl<ly transfer the black

lead to the battery "-" terminal and again take

careful note ofthe reading. The difference between

the two readings should not exceed 0.5 volts.

Readings in excess of this indicate a high resistance

in the ignition feed circuit, faulty ignition switch or

cut out button.

PART C

IGNITION COIL

The ignition coil consists of a primary and secondary

winding, wound concentrically about a laminated

soft iron core, the secondary winding being next to

the core.

The primary and secondary windings of the coil

have (280-372) 310 turn and 2'1,000 turns respec-

tively of enamel-covered wire, the secondary being

much finer. Each layer is paper insulated from the

next on both primary and secondary windings.

To test the ignition coil on the machine, first ensure

that the low-tension circuit is in order as described

in Part "A", then disconnect the high-tension lead

from the sparking plug. Turn the ignition switch to

the IGN position and crank the engine until the

contacts are closed.

Flick the contact breaker lever open a number of

times whilst the high-tension lead from the ignition

coil is held about 1f in. away from the cylinder head.

lf the ignition coil is in good condition a strong spark

should be obtained, if no spark occurs this indicates

the ignition coil to be faulty.

Before a fault can be attributed to the ignition coil

it must be ascertained that the high-tension cable is

not cracked or showing signs of deterioration, as

this may often be the cause of misfiring etc. lt should

also be checked that the ignition points are actually

making good electrical contact when closed and that

the moving contact is insulated from earth (ground)

when open. lt is advisable to remove the ignition

coil and test it by the method described below.

See Section D12for removing ignition coil.

BENCH TESTING IGNITION COIL

Connect the ignition coil into the circuit shown in

Fig. G3 and set the adjustable gap to 9 mm. With

the contact breaker running at 600 r.p.m., not more

than 5\ missing should occur at the spark gap over

a period,cf 15 seconds. The primary winding can be

checked for short-circuit coils by connecting an

ohmeter across the low-tension terminals. The

reading obtained should be within the figures quoted

below (at 20'C.).

Primary Resistance

Minimum Maximum

3.3 oh ms 3.8 ohms

Fig. G3. lgnition coil test rig

PART D

CONTACT BREAKER

Faults occurring at the contact breaker are in the

main due to, incorrect adjustments of the contacts

or the efficiency being impaired by piling, pitting,

or oxidation ofthe contacts due to oil etc. Therefore,

always ensure that the points are clean and that

the gap is adjusted to the correct working clearance

as described section 817.

To test for a faulty condenser, first switch on the

gnition, then take voltage readings across the

contacts when open. No reading indicates that the

condenser internal insulation has broken down.

Should the fault be due to a condenser having a

reduction in capacity, indicated by excessive arcing

.GREY FIBRE

OR BAKETISED

FABRIC BLOCK

CONTACT BREAKER

sw.oR -vE.

IERMINAT

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ELECTRICAL SYSTEM G

when in use, and overheating of the contact faces,

a check should be made by substitution'

Particular attention is called to the Periodic lubrica-

tion procedure for the contact breaker which is

given on page A10. When lubricating the parts

ensure that no oil or grease Sets on to the contacts.

lf it is felt that the contacts require surface grinding

then the comPlete contact breal<er unit should be

removed as described on Page 817, and the moving

contact disconnected by unscrewing the securing

nut at the low tension lead, removing the lead and

nylon bush. The spring and contact point can be

removed from the Pivot sPindle. Grinding is best

achieved by using a fine carborundum stone or very

fine emery cloth, afterwards wiping away any trace

of dirt or metal dust with a clean petrol (gasolene)

moistened cloth. The contact faces should be slightly

domed to ensure point contact. There is no need

to remove the pitting from the fixed contact.

When reassembling, the nylon bush is fitted through

the low tension connection tab, and through the

spring location eye. Apply a smear of grease to the

C.B. cam and moving contact Pivot Post. Every

3,000 miles and/or contact replacement, apply two

drops of clean engine oil to the rear of the three

lubricating felt wicks.

PART E

CHECKING THE HIGH.TENSION

CIRCUIT

If ignition failure or misfiring occurs' and the fault is

not in the low-tension circuit, then check the

ignition coil as described in Part "C". lf the coil

proves satisfactory, ensure that the high-tension

cable is not the cause ofthe fault.

lf a good spark is available at the hiSh-tension cable,

then the sparking plug suppressor caP or the

sparking plug itself may be the cause of the fault'

Clean the sparking plug and adjust the electrodes

to the required setting as described on page G.8

and then reset the engine for running performance'

lfthe fault re-occu rsthen it is I i kelythatthe su PPressor

cap is faulty and should be renewed.

2MC ELECTROLYTIC CAPACITOR

The capacitor is an electrolytic polarised unit, which

will be irreparably damaged if incorrectly connected'

TERMI NAL IDENTIFICATION

Looking at the terminal end of the unit, two

Lucar terminals of different sizes will be observed,

the small terminal being the Positive earth

terminal: for identification the rivet has a red

s Pot.

The double Lucar terminal is the negative con-

necti on.

The basic object of using the electrolytic caPacitor

in the system is to enable the motor cycle to be run

without a battery giving the rider the advantage of

using the machine for competition work, and

re-fitting the battery for normal.road use.

lf the battery should be disconnected and the

machine run on caPacitor ensure that the negative

(brown/blue) lead is well insulated.

PERIODIC CHECK

Disconnect the battery, start and run the engine.

Full lighting should be available.

Conclusion.-lf engine will not fire and run, Pro-

ceed to next check.

EFFICIENCY CHECK

(1) Disconnect the caPacitor.

(2) Connect the capacitor direct to a 12 volt

battery for 5 seconds (see polarity note).

(3) Disconnect the battery and let the charged

capacitor stand for 5 min utes'

(4) Connect a D.C. voltmeter across the terminals

(see polarity note) and note the steady reading

after the initial swing, which should not be less

than 9 volts for a serviceable unit.

SERVICE NOTES

Before running the machine with the battery dis-

connected it is essential that the battery negative

lead be insulated to Prevent it from reconnecting

and shorting to earth. This can be done by removing

the fuse from its holder and replacing it with a

length of *in. diameter wooden dowel or other

insulating medium.

A faulty capacitor may not be apparent when used

with a battery system. To prevent any inconvenience

arising, periodically check that the caPacitor is

serviceable by disconnecting the battery to see if

the machine will start easilY.

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GELECTRICAL SYSTEM

Should the engine fail to start without the battery,

substitute a new capacitor. lf the engine still will not

start, check the wiring between the capacitor and

rectifier for possible open or short-circuit condi-

tions. AIso check the earth connections.

Do not run the machine with the Zener diode

disconnected, as the capacitor wi ll be damaged due

to excessive voltage.

lf difficulty is encountered in starting with a battery

fitted, disconnect the capacitor to eliminate the

possibility of a short-circuit.

normally dissipated through to rhe cylinder head

not having an adequate conducting path. Over-

heating is normally symptomized by pre-ignition,

short plug life, and "pinking" which can ultimarely

result in piston crown failure. Unnecessary damage

can result from over-tightening the plugs. To

achieve a good seal between the plug and cylinder

head, screwthe plug in by hand on to its gasket, then

lightly tighten with a box spanner.

A plug of the correct grade will bear a light flaky

deposit on the outer rim and earth electrode, and

these and the base of the insularor will be light

chocolate brown in colour. A correct choice of

plug is marked (A). (B) shows a plug which appears

bleached, with a deposit like cigarette ash;this is too

"hot-running" for the performance of the engine

and a cooler-running type should be substituted.

ffi

"#sMffi&.

ffi

lSW

*|!W

'.1W

ffi

SECTION G4

SPARKING PLUG

It is recommended that the sparking plug be

inspected, cleaned and tested every 2,000 miles

(3,200 km.) and a new one fitted every 10,000 miles

(16,000 km.).

To remove the sparking plug a box spanner (j* in.,

19.5 mm. across flats) should be used and if any

diffculty is encountered a small amount of pene-

trating oil should be placed at the base of the

sparking plug and time allowed for penetration.

Examine the plug for signs of petrol (gasolene)

fouling. This is indicated by a dry, sooty, black

deposit, which is usually caused by over-rich

carburation, although ignition system defects such

as a faulty contact breaker, coil or condenser

defects, or a broken or worn out cable may be

additional causes.

Examine the plug for signs of oil fouling. This will

be indicated by a wet, shiny, black deposit on the

central insulator. This is caused by excessive oil in

the combustion chamber during combustion and

indicates that the piston rings or cylinder bore is

worn.

To rectify this type of fault the above menrioned

items should be checked with special attention

given to carburation system.

Overheating of the sparking plug electrode is

indicated by severely eroded electrode and a white,

burned or blistered insulator. This type of fault

can be caused by weak carburation or over-advanced

ignition timing although plugs which have been

operating whilst not being screwed down sufficiently

can easily become overheated due to heat that is

Fig. G4. Sparking plug diagnosis

I gl*

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ELECTRICAL SYSTEM G

A plug which has been running too "cold" and has

not reached its self-cleaning temperature is shown

at (C). This has oil on the base of the insulator and

electrodes, and should be replaced by a plug that

will burn off deposits and remove the possibility of

a short-circuit. The plug marked (D) is heavily

sooted, indicating that the mixture has been too

rich, and a further carburation check should be

made. At illustration (E) is seen a plug which is

completely worn out and in need of replacement.

To clean the plug it is Preferable to make use of a

properly designed proprietary plug cleaner. The

makers instructions for using the cleaner should be

followed carefully.

When the plug has been carefully cleaned, examine

the central insulator for cracking and the centre

electrode for excessive wear. ln such cases the

plug will have completed its useful life and a new

one should be fitted.

Finally, the sparking plug electrode should be

adjusted to the correct gaP setting of.025 in'

(.635 mm.). Before refitting sparking plug the

threads should be cleaned by means of a wire brush

and a minute amount of graphite grease smeared on

to the threads. This will prevent any possibility of

thread seizure occurring.

lf the ignition timing and carburation settings are

correct and the plug has been correctly fitted' but

overheating still occurs, then it is possible that

carburation is being adversely affected by an air leak

between the carburetter and the cylinder head.

This possibility must be checked thoroughly before

taking any further action. When it is certain that

none of the above mentioned faults are the cause of

over-heating then the plug type and grade should

be considered.

Normally the tyPe of plug quoted in General

Data is satisfactory for general use of the machine,

but in special isolated cases, conditions may demand

a plug of a different heat range. Advice is readily

available to solve these problems from the plug

manufacturer who should be consulted.

SECTION G5

CI.{ARGING

DESCRIPTION

The charging current is supplied by the two lead

alternator, but due to the characteristics of alter-

nating current the battery cannot be charged direct

from the alternator. To convert the alternating

current to direct current a full wave bridge silicon

type rectifier is connected into the circuit. The

alternator gives full outPut, all the alternator coils

being permanently connected across the rectifier.

Excessive charge is absorbed by the Zener Diode

which is connected in parallel with the battery.

Always ensure that the ignition switch is in

the OFF position whilst the machine is not in

use, to prevent overheating of the ignition

coils and discharging the battery.

Proceed to test the alternator as described in

Part "A". lf the alternator is satisfactory, the fault

must lie in the charging circuit, hence the rectifier

SYSTEM

must be checked as given in Part "B" and then the

wiring and connections as shown in Part "C".

PART A

CHECKING THE ALTERNATOR

OUTPUT

Disconnect the two alternator outPut cables and

run the engine at 3,000 r.P.m'

Connect an A.C. voltmeter (0-1 5 volts) with 1 ohm

load resistor in parallel with each of the alternator

leads in turn, and observe the voltmeter readings.

A suitable 1 ohm load resistor can be made from a

piece of Nichrome wire as shown in Part "D",

page G12.

The test is conducted by connecting a voltmeter

and the 1 ohrn load resistor between the following

cables and note the readings:-

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GELECTRICAL SYSTEM

Two Lead Stator

(a) Whiteigreen and greeniyellow-Voltmerer

should read 8.5 volts (minimum).

From the results obtained, the following deductions

can be made:--

(1) lf the readings are all egual to or higher than

those quoted then the alternator is satisfactory.

(2) A low reading on any group of coils indicates

either that the leads concerned are chafed or

damaged due to running on the chain or that

some turns of the coils are short-circuited.

(3) Low readings for all parts of the test indicate

that either the green/white lead has become

chafed or damaged due to rubbing on the chain

or that the rotor has become partially demag-

netized. As the latter is an extremely rare

occu rrence it is advisable to check by su bsi itution

before condemning the rotor. lf it is found that

the rotor has become demagnetized, check that

it has not been caused by a faulty rectifier and

that the battery is of correct polarity.

(4) A zero reading for any group of coils indicates

that a coil has become disconnected, is open-

circuit, or is earthed.

(5) A reading obtained between any one lead and

earth indicates that coil windings or connections

have become earthed.

lf any of the above mentioned faults occur, always

check the stator leads for possible chain damage

before attempting repairs or renewing the stator.

It is beyond the scope of this manual to give

instruction for the repair of faulty stator windings.

However, the winding specification is given in the

Table, on page G15 for those obliged to attempt

rePair work.

PART B

RECTIFIER MAINTENANCE

AND TESTING

The rectifier is a silicon semi-conductor device

which allows current to flow in one direction only.

It is connected to provide full wave rectification of

alternator outPut current.

The rectifier requires no maintenance beyond

checking that the connections are clean and tight.

G10

The nuts clamping the rectifier plates together

must not under any circumstances be slackened. A

separate nut is used to secure the rectifier to the

back of the toolbox and it is important to check

periodically that the rectifier is firmly attached.

When tightening the rectifier securing nut, hold

the spanner as shown in Fig. G5, for if the plates

are twisted, the internal connections will be broken.

Note the circles marked on the fixing bolt and nut

indicating that the thread form is U.N.F.

Fig. G5. Securing the rectifier

TESTING THE RECTIFIER ON THE

MACHINE

(1) Disconnect the Zener Diode by removing the

straight Lucar connector with the Brown/Blue

cable from the 2MC capacitor.

(2) Locate the snap connector junction for the

Brown/Blue cable to the box and disconnect.

(3) Connect a D.C. voltmeter (with the 1 ohm load

in parallel) with the red lead to earth and the

Black lead to the Brown/Blue cable from the box.

(4) Locate the White/Yellow cable in the other

snap connector junction from the box, and

using a jumper lead connect the cable from the

box to the negative (-) terminal of the battery.

(5) Start the machine and run at approximately

3,000 rev./min., and take a reading from the

voltmeter. This should read not less than 7.5

volts, which indicates the rectifier is operating

satisfactorily. A lower reading indicates a fault

in the rectifier which can be confirmed by a

bench test.

(6) Stop engine before disconnecting the voltmeter.

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ELECTRICAL SYSTEM G

BENCH TESTING THE RECTIFIER

For this test the rectifier should be disconnected

and removed. Before removing the rectifier,

disconnect the leads from the battery terminals to

avoid the possibility of a short-circuit occurring.

Connect the rectifier to a fully charged 12 vok'

battery of approximately 40 amperei hours caPacity

at the10 hour rate, and 1 ohm load resistor, and then

Fig. G5. Rectifier-showing terminal connections for

bench tests I and 2

I cnrcrtNc FoRwARD REslsrANcE

connect the D.C. voltmeter in the V2 position. as

shown in Fig. G7. A voltmeter in position Vl will

measure the volt drop across the rectifier plate.

ln position V2 it will measure the supply voltage to

check that it is the recommended 12 volts on load.

Note the battery voltage (should be 12 volt) and

then connect the voltmeter in V1 position whilst

the following tests are conducted.

APPROX 50AMP-HOUR

l2v. BATTERY

Frg. G7. Benclr testing the rectifier

->{" >:Y

,^it / -r'>*- 4

TEST

'>4, u."

a-1 r-f

--rYr)t--' t.:;k

TEST 2 cHEcKtNG BAcK LEAKAGE

):I:'

>--1 1< -;f.

ll il

-:+:' )"1..1 -X' )*

,^{t ,^. , * .rti .>--4

0 """k,,f" 1la/_'

'*, )Y,

^\r*

, \/l

\ / Yl,

, __,)tl i"'.r-o

?);i.l,{.

)*- -:i'

-tY' ''-r{a

Fig. G8. Rectifier test sequence t42

G11

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ELECTRICAL SYSTEM

ln Fig. G8, the re*ifier terminal marl<ing 1,7 and

3 are as shown physically in Figs. G6 and G7,

while terminal 4 representsthe rectifier center bolt.

1 and 3 are the A.C. input terminals while 2 and 4

are the D.C. output terminals ( -ve and f ve

res pecti vel y)

TEST 1

With the test leads, make the following connections

but keep the testing time as short as possible to

avoid overheating the rectifier cell: (A) 1 and 2,

(B) 1 and 4, (C) 3 and 4, (D) 3 and 2. Each reading

should not be greater than 1.5 volts with the battery

polarity as shown.

TEST 2

Reverse the leads or battery polarity and repeat

Test 1. The reading obtained should be the same as

the battery voltage (V2).

lf the readings obtained are not within the figures

given, then the rectifier internal connections are

faulty and the rectifier should be renewed.

PART C

CHECKING THE CHARGING

CIRCUIT FOR CONTINUITY

This test utilizes the machine's own battery ro test

for continuity or breakdown in the A.C. section of

the charging system.

The battery must be in a good state of charge and

connected correctly into the circuit *ve earth

(ground) and the alternator leads must be dis-

connected at the snap connectors so that there is no

possibility of demagnetizing the rotor.

First, check that there is voltage at the rectifier

centre terminal by connecting a D.C. voltmeter,

DESCRIPTION

The Zener Diode output regulating system which

uses the coils of the alternator connected perman-

ently across the rectifier, provides automatic control

of the charging current. ltwill only operate success-

fully on a 12 volt system where it is connected in

parallel with the battery as shown in the wiring

diagram, Fig. G13.

G12

SECTION G6

ZENER DIODE CHARGE CONTROL

with 1 ohm load resistor in parallel, between the

rectifiercentreterminal and earth, remember (+ ve)

positive earth (ground). The voltmeter should read

dattery volts. lf it does nor, there is a fau lty

connection in the wiring.

PART D

CONISTRI..'CTING A 1 OHM

LOAD RESISTOR

The resistor used in the following tests must be

accurate and constructed so that it will not overheat

otherwise the correct values of current or voltage

will not be obtained.

A suitable resistor can be made from 4 yards (3f

metres) of 18 s.w.g. ('048 in., i.e.,1'2 mm. diameter)

Nichrome wire by bending ir into rwo equal parts

and calibrating it as follows:-

(1) Fix a heavy gauge flexible lead to the folded end

of the wire and connect this lead to the positive

terminal of a 6 volt battery.

(2) Connect a D.C. voltmeter (0-1 0 volts) across

the battery rerminals and an ammeter (0-1 0

amp.) between the battery negative terminal

and the free ends ofthe wire resistance, using a

crocodile clip to make the connection.

(3) Move the clip along the wires, making contact

with both wires until the ammeter reading is

numerically equal to the number of volts shown

in the voltmeter. The resistance is then 1 ohm.

Cut the wire at this point, twist the two ends

together and wind the wire on an asbestos

former approximately 2 in. (5 cm.) diameter so

that each turn does not contact the one next to

it.

Assuming the battery is in a low state of charge its

terminal voltage (the same voltage is across the

Diode) will also be low, therefore the maximum

charging current will flow into the battery from the

alternator. Atfirst noneofthe current is by-passed

by the Diode because of it being non-conducting

due to the low battery terminal volts. However, as

the battery is quickly restored to a full state of

charge, the system voltage rises until at 13.5 volts

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ELECTRICAL SYSTEM G

the Zener Diode becomes partially cond ucting,

thereby providing an alternative Path for a small

part of the charging current. Small increases in

battery voltage result in large increases in Zener

conductivity until, at aPProximately 15 volts about

5 amperes of the alternator outPut is by-passing the

battery. The battery will continue to receive only a

portion of the alternator outPut as long as the

system voltage is relatively high.

Depression of the system voltage, due to the use of

headlamp or other lighting equipment, causes the

Zener Diode current to decrease and the balance to

be diverted and consumed by the comPonent in use.

lf the electrical loading is sufficient to cause the

system voltage to fallto 13'5 volts, the Zener Diode

will revert to a high resistance state of non-con-

ductivity and the full generated outPut will go to

meet the demands of the batterY.

PART A

MAINTENANCE

The Zener Diode is mounted in the aluminium elec-

trical box beneath the fuel tanl<. No maintenance

will be necessary excePt to ensure a good firm flat

metal to metal contact between the base of the diode

and the surface of the heat sink to ensure maximum

efiiciency. Ensure the earth connection to the Diode

is a good one.

TERMINAL

BLADE

The "earthing" stud which secures the Diode to

the heat sink, must not be subjected to a tightening

torque greater than 22-28 lb./in. The earth wire

must be fitted under the fixing nut, not between

the Diode and heat sinl<.

CHECKING PERFORMANCE OF

ZENER DIODE

The battery should be fully charged before starting.

lfthere is any doubt about the state ofcharge ofthe

battery, it should be recharged before commencing

the test.

lsolate the Zener Diode by disconnecting all leads

from the 2MC capacitor.

Connect a D.C. voltmeter Blacl< lead to the straight

Lucar with the Brown/Blue cable and the voltmeter

Red lead to earth. Connect a D.C. ammeter Red

lead to the straight Lucar with the Brown/Blue

cable, and the Black lead to the right angle Lucar with

a Brown/Blue cable. Checl< all electrical equipment

other than the ignition is switched off. Start the

engine and raise r.p.m. to aPProximately 3,000.

Take a careful note cfthe readings.

As the system voltage rises to 12'75 volts no reading

should occur on the ammeter. The voltage will then

continue to rise and after 12'75 volts the ammeter

should start to read. The next check occurs when

the ammeter rises to 2 amps, at this point the volt-

meter should read between 13'5 and 15'5 volts.

Conclusions: The Zener Diode must be replaced

if:-

(1) Current flow commences before 12'75 V. is

reached.

(2) Voltmeter registers more than 15'5 V. before

2 amps is shown on the ammeter'

EARTHING

STUD

Fig, G9. Zener Diode

G13

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GELECTRICAL SYSTEM

SECTION G7

ELECTRIC HORN

DESCRIPTION

The horn is of a high frequency single-note type and

is operated by direct current from the battery. The

method of operation is that of a magnetically

operated armature, which impacts on the core face,

and causes the tone disc ofthe horn to vibrate. The

magnetic circuit is made self-inrerrupting by

contacts which can be adjusted externally.

lf the horn fails to work, check the mounting bolts

etc., and horn connection wiring. Check the battery

for state ofcharge. A low supply voltage at the horn

will adversely effect horn performance. lf the above

checks are made and the fault is not remedied, then

adlust the horn as follows.

HORN ADJUSTMENT

When adjusting and testing the horn do not depress

the horn push for more than a fraction of a second

or the circuit wiring may be overloaded.

A small adjustment peg situated near the terminals

(see Fig. G10) is provided to take up wear in the

internal moving parts of the

this peg anti-clockwise until

sound, and then turn it back

quarter to half a turn.

Fig. G10. Electric horn showing adiustment screw

Access to the bulb in rhe tail and stop lamp unit is

achieved by unscrewing the two slotted screws

which secure the lens. The bulb is of the double

filament offset pin type and when a replacement is

carried out, ensure that the bulb is fitted correctly.

Check that the two supply leads are connected

correctly and check the earth (ground) lead to the

bulb holder is in satisfactory condition.

When refitting the lens, do nor over-tighten the

fixing screws or the lens may fracture as a result.

G14

SECTION G8

TAIL AND STOP LAMP UNIT

25 W67

SEAL NG

RU B 8EE

horn. To adlust, turn

the horn just fails to

(clockwise) about one-

Fig. Gl1. Stop and tail lamp dismantled

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ELECTRICAL SYSTEM

SECTION G9

ALTERNATOR-ADDITI O NAL I N FORMATIO N

Specifications and Output Figures

Stator

No.

System

Voltage

Alternator Output

minimum A.C.

volts at 3,000 r.p.m.

Stator Coil Details

Connect White/Green

and Green/Yellow

with resistance

No. of

Coils

Tu rns

per coil S.W.G.

47705

(2 lead)

12 volts 8.5 6140 72

SECTION G IO

DIRECTION INDICATOR LAMPS

Access to the bulb is gained by removing the lens contact with the inside of the lamp shell'

which is retained by two screws' lmportant:-Whentighteningthe pillarlocking nut

Before fitting a new bulb, check that the earthing against the lamp shell, it is essential that the torgue

clip on the back of the bulb holder is in good settingislimitedto35-45lb.ins.(0'41-0'52kg.t.).

SECTION G I I

IGNITION SWITCH

The 149 S.A. switch incorporates a barrel-type lock contact and clean if necessary. To remove the

using "yale" type keys and renders the ignition ignition switch refer to Section D12.

circuit inoperative when turned to the "OFF"

position and the key removed. when removing the ignition switch the battery

leads should be disconnected to avoid the possibility

Check the Lucar connections for good electrical ofashortcircuit.

SECTION GI2

OTHER LIGFIT UNITS

The headlamp shell contains three warning lights speedometer head'

and a parking light, access being gained to each of

them by first removing the rim and light unit Each bulb holder is a push-fit into its resPective

assembly. component, and the bulbs are located by means of a

bayonet fitting except for the speedometer light

The speedometer light is housed in the base of the which has a screw type bulb.

G15

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GELECTRICAL SYSTEM

DESCRIPTION

The headlamp is of the pre-focus bulb light unit type

containing the hi-beam warning light, oil pressure

warning light and a rotary lighting switch. Access

is gained to the bulb and bulb holder by withdrawing

the rim and light unit assembly. To do this slacken

the screw at the top ofthe headlamp shell just behind

and adjacent to the rim and prise off the rim and

light unit assembly.

The bulb can be removed by first pressing the

cylindrical adapter inwards and turning it anti-

clockwise. The adapter can then be withdrawn and

the bulb is free to be removed.

When fitting a new bulb, note that it locates by

means of a cut-away and projection arrangement.

Also note that the adapter can only be replaced one

way, the tabs being staggered to prevent incorrect

reassembly. Check the replacement bulb voltage

and wattage specification and type before fitting.

CENTRE LINE OF MACFIINE

SECTION G 13

H EADLA M P

25W68

Fig, G12. Beam adiustment

Focusing with this type of unit is unnecessary and

there is no provision for such.

The speedometer light is housed within the base

of the speedometer head.

Each bulb holder is a push-fit into its respective

component, and the bulbs are located by means of

a peg arrangement, except for the speedometer

light which has a screw type bulb.

BEAM ADJUSTMENT

When the motorcycle carries its normal load, the

headlamp full-beam should project straight ahead

and parallel with the road surface.

To achieve this, place the machine on a level road

pointing towards a wall at a distance of 25 feet

away, with a rider and passenger, on the machine,

slacken the two headlamp fixing bolts at either

side and tilt the beam unit until the beam is focused

as indicated in Fig. Gl 2. Do not forget that the

headlamp should be on "full beam" Iighting during

this operation. Tighten the bolts fully after adjust-

ment.

OF LIG}.IT

FIEIGHT

CENTRE OF LAMP

FROM GROUND

CONCENTRATED ARFA

G16

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ELECTRICAL SYSTEM

)

Z^ a 6,^

YEz=

690=

U O E-

2 Z -u,., Fr

oz=-o

o o:fr m

% = -r;"-?

i o a>oL

t "rl

_EO

cft

> O.r

Z -J

oa z

l-z

z\2

G17

Fig. Gl3. Wiring diagram

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sEcTroN J

SERVICE TOOLS

INTRODUCTION

This section of the Workshop Manual illustrates pictorially the workshop service tools that

are available for carrying out the major dismantling and reassembly operations on the

UNIT CONSTRUCTION-250 c.c. TRIUMPH MOTORCYCLE.

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SERVICE TOOLS

Fig. Jl.

Valve seat cutter No. D1832

Blender cutter No. D1835

Arbor, pilot assembly No. D|853

Fig. t2.

Piston ring slipper

No.6l-5031 (65-70 mm.)

Fig. J3.

Valve guide removal and

replacement tool. No, 6l-6063

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SERVICE TOOLS J

Flg. t4.

Contact breaker cam removal tool

No.6l-3816

Fig. J5. T.D.C.

locating plunger and bodY

Nos. D2195/D572

Fig. J5.

Clutch sleeve extra€tor No. 61-3583

Fig. J7.

Ctutch locking tool No. 6l-3774

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TSERVICE TOOLS

tFig. Jl0. Contact breaker oil seal spreader

No. 2168

At44

Fig. Jll. Crank protection cap No.61-3819

(For use with extractor No. 61-3808)

ff 25W75

Fig. J8. Pinion extractor set

No. 51-3808

25W76

Fig. J9. Crankshaft balance weight

No.61-3809

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SERVICE TOOLS

Fig. J12. Crankcase Parting tool No. 2155

Fig. J13. Crankcase assembly tool No. Zl57

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JSERVICE TOOLS

Fig. tl4. Wheel bearing retainer peg spanner

No. 5l-3694

Fig. t17

Crankshaft bearing removal tool No. D3677

Fig. Jl5.

Head race bearing drift No. 6l-5113

Fig. Jl6.

Fork damper valve removing tool No. 61-6121

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CONVERSION

TABLES

cT1

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CT CONVERSION TABLES

INCHES TO MILLIMETERS-UNITS

lnches 0 10 20 30 40

0254.0 508.0 762.0 1016.0

125.4 279.4 533.4 787.4 1041.4

250.8 304.8 558.8 812.8 1066.8

376.2 330.2 584.2 838.2 1092.2

4101 .6 355'6 609'6 863.6 1117.6

5127-O 38'1.0 635.0 889.0 1143.0

6152.4 406.4 660.4 914.4 1168.4

7177.8 431.8 685.8 939.8 1193.8

I203.2 457.2 711.2 965-2 1219.2

9228.6 482.6 736.6 990.6 1244.6

One lnch-25.399978 millimetres

One Metre-39.37011 3 inches

One Mile-1.6093 Km

One Km-.62138 miles

DECI MALS TO M I LLI M ETRES-FRACTIO N S

11100

i n ches mm.

.01 .254

.02 .508

.03 .726

.o4 1 .016

.05 1.270

.06 1.524

.07 1.778

'08 2.032

09 2.286

1 /1 000

i nches mm.

.001 .0254

.002 .0508

.003 .0762

.004 -1016

.005 1270

.006 .'t524

.007 .1778

.008 .2032

'009 .2286

1t10

L r-

rnches I mm

.1 2.54

-2 5.08

.3 7.62

.4 14.16

'5 12.70

-6 15.24

.7 17.78

.8 20.32

.9 22.86

CT7

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CONVERSION TABLES CT

FRACTIONS TO DECIMALS AND MILLIMETR,ES

F ractions Decimals mm.

1164 .01 5625 -3969

1132 .031 25 -7937

3164 .04687s 1-1906

1116 .0625 1.5875

5t64 .078125 1.9844

3132 '0937s 2.3812

7164 .'t09375 2.7781

1t8 -125 3.'1750

9 t64 444625 3.5719

s l32 -15625 3.9687

11 164 171875 4.3656

3116 .1875 4.7625

13164 .203125 5.1594

7132 .21875 5.5562

15t64 .234375 5.9531

114 .25 6.3500

17 164 265625 6.7469

e 132 28125 7.1437

't9164 296875 7-5406

s116 3125 7.9375

21 164 328125 8.3344

11132 .34375 8.7312

23164 .359375 9.1281

3/8 .375 9.5250

2s 164 390625 9.9219

13132 40625 10'31 87

27164 421875 10.7156

7116 .4375 11.',!125

29164 .453125 11.5094

1s132 .46875 11.9062

31 164 484375 1 2.3031

't 12 .5 12.7000

Fracti ons Decimals mm.

33164 .5'15625 '13.0969

17132 .531 25 13.4937

35t64 .546675 1 3.8906

e 116 .5625 14.287s

37164 -57812s 14.6844

19132 .59375 15.0812

39164 -60937s 15.478'l

s/8 .625 1 5.8750

41 164 -640625 16.2719

21!32 .65685 16.6687

43 t64 .671875 17.06s6

1',t 116 .6875 17.4625

4s164 .703125 17.8594

23132 '71875 18.2562

47 164 .734375 '18'653'l

314 .75 1 9.0500

49164 .765625 19.4469

25132 .7g'.t25 19.8437

sl164 .79687s 20.2406

13116 '8125 24"6375

s3164 .828125 21.0344

27 32 .84375 21.4312

ssl64 .859375 21.8281

718 .875 22.2250

s7 164 .890625 22.6219

29132 .90625 23.O187

s9164 .921875 23.4156

1s116 '9375 23.8125

61 164 .9531 25 24.2094

31132 .96875 24.6062

63164 .984375 25.0031

25.4000

cT3

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CT CONVERSION TABLES

MILLI MFTRES TO INCI.{ES-UNITS

MILLIMETRES TO INCHES-FRACTIONS

I 1100

mm. i nch es

0.01 .00039

0.02 '00079

0.03 '001 18

0'04 .00't 57

0.0s .00197

0.06 .00236

0.07 .04276

0.08 .00315

0.09 .003s4

mm. 0 10 20 30 40

0.3937C .78740 1.181't0 1.57480

1.03937 .43307 '82677 1-22047 1.61417

2.07874 .47244 .86614 1.25984 1'65354

311811 '511 81 .90551 1.29921, 't-69291

4 15748 '551 1 I.94488 1.33858 1.73228

5'1968s .59055 .98425 1.37795 1-77165

6.23622 .62992 1.02362 1.41732 1 .81103

7.27559 .669?-9 1.06299 1.45669 1'85040

8'31496 .70866 I .10236 1.49606 1.88977

9.35433 .74803 1.14173 1.53543 1.92914

mm. 50 60 70 80 90

01.96851 2.36221 2.75591 3.14961 3.5433'l

12.00788 2.40158 2.79528 3.1 8891 3.58268

22.04725 2.44495 2.83465 3.22835 3.62205

32.08662 2.48032 2.87402 3.26772 3-66142

42.'.t2599 2-51969 2.91339 3'30709 3.70079

52-16s36 2.55906 2.95276 3.34646 3.74A16

62.20473 2.59843 2 99213 3.38s83 3.77953

72.24414 2.63780 3.031 s0 3.42520 3'81 890

I2.28347 2.67717 3.07087 3.46457 3.85827

92.32284 2.71654 3.11024 3'50394 3.89764

1 /1 000

mm. inches

0.001 .000039

0'002 .000079

0.003 .0001 1 8

0.004 .0001 57

0.005 .000197

0.006 '000236

0.007 .000276

0'008 .00031 5

0.009 .000354

1110

mm, i n ches

0.1 00394

0.2 .oo787

0.3 .o1't81

0.4 .01575

0.5 .01969

0.6 -02362

0'7 .02756

0.8 .031 50

0.9 .03543

CT4

www.bsaunitsingles.com

CONVERSION TABLES CT

Lette rSize Letter Size

A.234 N.302

B.238 o.316

c.v42 P.323

D-246 o'332

E.250 R.339

F.257 c.348

G.261 T'358

FI .266 U.368

.277 .377

I'277 .386

K.281 X'397

L.290 Y.404

M295 z.413

DRILL SIZES

WIRE GAUGES

Number Size N u rnber Size Number Size Number Size

1'2280 14 .1820 27 .1440 40 .0980

2.7210 15 .1800 28 .1405 41 '0960

3.2130 16 .1770 29 .1 360 42 .0935

4.2090 17 1730 30 "1 285 43 .0890

5.2055 18 .1695 31 1 200 44 .0860

6.2040 19 .1660 )z 1160 45 0820

7.2010 20 .1610 33 .11 30 46 .081 0

8.1990 21 '1 s90 34 1110 47 .0785

9.1960 22 1570 35 1 100 48 .0760

10 .1935 23 1540 36 'r 06s 49 .0730

11 1910 24 1 520 37 '1040 50 '0700

12 1 890 ?q .1495 38 .101 551 '0670

13 .1850 26 1470 39 '0995 52 .0635

Brow,n and Sharpe's

American Wire Gauge

.460

.410

.365

.325

.289

'258

-229

.204

.187

.162

.144

.128

.114

.102

.091

.081

.072

.064

.457

.051

.045

'040

.035

.032

.028

.025

.023

'020

'018

.0'16

014

.012

'011

.010

11.684

10-404

9.265

8.251

7.348

6-543

5.827

5.189

4.621

4.115

3.664

3.263

2.906

2.588

2.304

2.052

1.827

1.627

1.449

1.290

1.149

1.009

.911

.811

.722

.643

.573

.511

.454

.404

.360

.321

.285

.254

0000

000

'18

.400

.372

.348

.324

.300

.276

.252

.232

.212

.'t92

.176

'160

.144

.128

.116

.104

.092

.080

.072

.064

.056

.048

.040

.036

.032

.028

.024

.022

.020

.018

.0164

.0148

.01 36

.0't24

10.160

9.448

8 839

8.299

7.620

7.010

6.400

5.892

5.384

4.676

4.470

4.064

3.657

3.251

2.946

2.641

2.336

2.032

1.828

1.625

't.422

1.219

1.016

.9',t4

.812

.7'11

.609

'558

.508

.457

-416

.375

.345

.314

millimetres

CT5

www.bsaunitsingles.com

CT CONVERSION TABLES

B.S.W. SCREW THREADS

Dia. of

bolt

(i n ch)

Th reads

Per

in ch

Dia. tap

d rill

(inch)

Core

dia. Area at

thd. root

sq. in.

PITCH

Nut

max. lmin.

AMETER

Bolt

max. lmin.

HEX.

Flats Corners

(mean) |

Nut

th i ckn ess

(.00s)

114 20 .1968 .1860 .0272 .224s I i,oo -522 '6'l -245

s 116 18 114 .2417 .0458 .2836 -2789 .2769 .2722 '597 .69 .307

3/8 16 s116 .2950 .0683 .3420 3370 '3350 3300 -707 .82 .370

7116 't4 23t64 .3460 .0940 .3991 .3938 .39't 8.3865 .817 .95 -432

112 12 13132 3933 .1215 .4544 .4486 .4466 .4408 .917 1.06 .49s

e 116 12 1s 132 .4558 .1632 .5169 .5111 .5091 .5033 1.006 1.'.t7 '557

s/8 11 17132 .5086 .2032 .s748 .5688 .5668 .5608 1.096 't-27 .620

11l't6 11 37 164 .5711 -2562 .631 3-6293 '1196 1.39 .682

314 't0 41164 .6219 .3038 '6943 '6880 '6860 .6797 1.296 1.50 .745

13116 10 4s 164 .6844 .3679 7506 .7485

718 9314 '7327 .4216 .8126 .8059 .8039 .7972 1.474 1.71 .870

'ts l16 913 t16 '7952 .4966 .8684 .8664

1Iss 164 .8399 .s540 .9291 -9220 .9200 .9129 1.664 '1.93 .995

B.S.F. SCREW THREADS

Dia. of

bolt

(inch)

Th reads

Per

i nch

Dia. tap

d rill

(i n ch)

Core

dia. Area at

thd. root

sq. in.

PITCH DIAMETER

Nut I Bolt

max. lmin. Iru*. 1min.

HEX.

Flats Corners

(mean) |

Nut

th i ckness

(mean)

7132 28 .1770 .1731 .0235 .2018 '1980 .1960 .1922 412 .48 166

114 26 .2055 2007 .0316 -2313 .2274 .2254 .2215 -442 .51 195

el32 26 .238 2320 .0423 .2625 .0586 .2565 -2527

s116 22 -261 2543 .0508 .2897 .2854 .2834 .2791 .522 '6',1 -245

3/8 20 316 .31't 00760 .3495 '3450 .3430 .3385 .597 .69 -307

7116 18 3/8 .3664 '1054 .4086 .4039 .4019 .3372 '707 '82 .370

112 16 27 164 .4200 '1385 '4670 '4620 .4600 .4550 .817 .95 .432

e 116 16 .492 -4425 "1 828 .5295 .5245 .5225 .5175 .9'.17 '1.06 .495

s/8 14 3s164 .5335 2235 5866 .s81 3'5793 -5744 1.006 1.17 .557

11116 14 39164 .s960 2790 -6491 .6438 .6418 .6365 1.096 1.27 .620

314 12 21132 .6433 '3250 .7044 .6986 .6966 .6908 1.196 1.39 682

13116 12 23 t32 .70s8 391 3 7669 .7611 .7s91 '7533

718 11 25t32 7586 .4520 .8248 .8188 .8168 .8108 1.296 1.50 .745

10 57 64 .87',t9 .5971 .9443 '9380 .9360 .9297 1.474 1.71 .870

1-118 91.9827 .7585 1.0626 1.0559 1.0539 1.0472 1.664 1.98 .995

1114 91-118 1.1077 .9637 1.'1876 1 .1809 1.7819 1|t722 1.852 2.15 1115

1 -3/8 I1-15164 1-2149 '1593 1.3041 1.2970 1.2950 1.2879 2-042 2.37 1.240

1-112 81'358 1.3399 .4100 1.4291 1.4220 1-4200 1.4129 2.2'10 2.56 1.365

1 -s/8 81-31164 1.4649 1.6854 1.5541 1-5470 1'54s0 1.5379 2-400 2.78 1.400

cT6

www.bsaunitsingles.com

CONVERSION TABLES CT

B.S.C. SCREW THREADS

Dia. of

bolt

(i nch)

1 8

THDS, PER INCH

Pitch

(i n ch)

0.02500

Depth of

th read

(i n ch)

0.0133

BASIC DIAMETERS (lnch)

Normal

series

20 T.P.l.

series Major

.01 250 Effective

0.1117 Minor

0'0984

s l32 32 0.03125 0.0166 0.1 563 0.1397 0.1231

3116 32 0.031 2s 0.0166 0.1875 0.1709 0.'t543

7132 26 0.03846 0.0205 0.2'188 0.1983 0.1778

114 26 0.03846 0.0205 0.2500 0.2295 0.2090

e l32 26 0.03846 0.0205 0.2813 0.2608 o.2403

s 116 26 0.03846 0.0205 0'3125 0.2920 0.27't5

3/8 26 0.03846 0.0205 0.3750 0.3s45 0.3340

7t16 j26 0.03846 0.0205 0.4375 o.4't70 0.3965

20 0.05000 0.0266 0.4375 o.4109 0.3843

1i2 1

26 0.03846 0.0205 0.5000 o.4795 0.4s90

20 0.05000 0.0266 0.s000 0.4734 0-4468

et16 t26 0.03846 0.0205 0.562s 0.5420 0'521 5

20 0.05000 0.0266 0'5625 0's359 0.5093

(

si8 1

26 0.03846 0.020s 0.6250 0.6045 0.5840

20 0.05000 0.0266 0'6250 0.5984 0's718

(

11116 <t

26 0.03846 0.0205 0.6875 0'6670 o.6465

20 0'05000 0'0266 0.6875 0.6609 0.6343

(

314 1

26 0.03846 0.0205 0.7500 0.7295 0.7090

20 0'05000 0.0266 0.7s00 0.7234 0.6968

cT7

www.bsaunitsingles.com

CT CONVERSION TABLES

B.A. SCREW THR,EADS

No. Dia. of

bolt Thds.

per inch Dia. tap

d rill Core

d ia.

Area at

thd. root

sq. in.

PITCH D

Nut

max. I m in.

AMETER

Bolt

max. lmin.

HEX.

Flats lCorners

Nut

thickness

0.2362 25.4 .1960 .1890 .0281 .2165 .2126 2't26 .2087 .413 .47 '236

1.2087 28.2 .1770 .166'l .0217 .'1908 .1875 .1873 1 838 .365 43 .209

2.1850 31.4 1520 1468 .0'169 1693 '1659 .1659 -1626 .324 .37 185

31614 34.8 .'1 360 1269 .0126 1472 1441 1441 .1409 -282 .33 161

4,1417 38.5 1160 fl46 '0096 1290 1261 1261 .'t231 248 .29 -142

5.1260 43.0 1440 .0981 .0075 1147 .1119 11't9 .1091 224 .25 .126

61102 47.9 .0935 '0852 '0057 .1000 '0976 '0976 '0953 19? .22 110

70984 52.9 .0810 '0738 .0045 '0893 .0869 .0869 .0845 '172 .20 .098

8.0866 59.1 .0730 .0663 .0034 '0785 '0764 .0764 -0742 .152 18 .087

9.0748 65.1 .0635 .0564 .0025 .0675 '0656 .0656 .0636 .131 15 '07s

10 .o669 72.6 .0550 .0504 -0021 .0587 .0587 117 14 '067

11 .0591 81.9 .0465 .0445 .00't6 .103 "t2 .059

12 .051'l 90.9 .0400 .0378 .0011 .090 '10 .051

13 .0472 102.0 .0360 .0352 .0010 '083 .09 .o47

14 .0394 109.9 '0292 '0280 .0006 '069 .08 .o29

15 .0354 120.s .0260 .0250 '0005 .061 -07 .035

16 .0311 1 33.3 .0225 .0220 .0004

cT8

www.bsaunitsingles.com

CONVERSION TABLES CT

FOOT POUNDS TO KILOGRAMETRES

M!LES TO KILOMETRES

POUNDS TO KILOGRAMS

01234567I9

1.383

2.765

4.148

5.530

6.913

8'295

9.678

11.060

'12.443

0.'1 38

1-114

2.903

4.286

5.668

7.051

8.434

9'816

11.199

12.581

o.277

1.659

3.042

4.424

5.807

7.189

8.572

9.954

11.337

12.719

0.4'ts

1.797

3.180

4.562

5.945

7.328

8.710

10.093

11.475

12.858

0.553

1.936

3'318

4-701

6.083

7.466

8.848

10.231

11.6'.13

12.996

0.691

2.074

3.456

4.839

6.221

7.604

8.987

1 0.369

11.752

13.134

0.830

2.212

3.595

4.977

6.360

7.742

9.125

1 0.507

'11.890

13.272

0.968

2.350

3'733

s.1't6

6.498

7.881

9.263

10.646

12.028

13.411

1.106

2.489

3'871

5.254

6'636

8.019

9.401

10.784

12.166

1 3.549

1.244

2.627

4.009

5.392

6.774

8.1 57

9.540

10.922

1 2.305

13.687

0113456789

16.093

32'187

48.280

64.374

80.467

96.561

112.6s4

128.748

'144.841

1'609

17.703

33.796

49.890

65.983

82.077

98.170

114.264

't 30.357

146.451

3.719

't9.312

35.406

51.499

67.593

83.686

99.780

'115.873

131.967

148'060

4.828

20.922

37.01 5

53.108

69.202

85.295

10't .389

117.482

'1 33.576

149.669

6.437

22.531

38-624

54.718

70.811

86.905

102.998

119.092

1 35.185

151.279

8.047

24-140

4A.234

56.327

72.421

88.51 4

1 04.608

110.701

136.79s

1 52'888

9.656

25.750

41.843

57.936

74.030

90.123

106.217

122.310

138.404

154.497

11.265

27.359

43.452

59.546

75.639

91-733

107.826

123'920

140.013

156.107

12.875

28.968

45-462

61.155

77.249

93.342

109.436

125.529

141.623

157.7'16

14'484

30.578

46.671

62.765

78'858

94.951

't11.045

127.138

143.232

159.325

01L3456789

4-536

9.072

'13.608

18.144

22.680

27.216

31.751

36.287

40.823

o.454

4.994

9'525

14.061

18.597

23.133

27.669

32.205

36.741

41.277

0.907

5.443

9.079

14.515

19'051

23.s87

28.123

32.659

37.195

41.731

1.361

5.897

10.433

14'968

19.504

24.040

28.576

33.112

37.648

42'184

1.814

6.350

't 0.886

15.422

'19.958

24.494

29.030

33'566

38'102

42.638

2.268

6.8A4

11.340

15.876

24.412

24.948

29.484

34'019

38.855

43.091

2'722

7.257

1'.t.793

16.329

20.865

25.401

29.937

34.473

39.009

43.545

3.175

7.711

12.247

16.783

21.319

25.8ss

30.391

34.927

39.463

43.998

3.629

8'165

12.741

17.237

21.772

26.308

30.844

35.380

39-916

44.452

4.082

8.618

13.1s4

17-690

22.226

26.762

31.298

35.834

40.370

44-906

MTLES PER GALLON (!MPERIAI-) TO LITRES PER, 100 KILoMETRES

10 28.20

10+ 26.9s

11 25.68

11+ 24.s6

12 23.54

12+ 22.60

't 3 21.73

13+ 20.92

14 20.18

14+ 19.48

1 5 18.83

1s+ 1e.22

16 17.66

16+ 17.12

17 16.61

17+ 16.14

18 15.69

18+ 1s.27

19 14.87

19+ 14.49

20 14.12

20+ 13.78

2'.t 13.45

21+ 13.14

22 12.84

22+ 12.ss

23 12.28

23+ 12.02

24 11.77

24+ 11.53

25 11 .30

2s+ f.a8

26 10.87

26+ 10.66

27 10.46

27+ 14.27

28 10.09

28+ e.e1

29 9.74

29+ 9.s8

6 89 I sl s.s4

6.73 I s2 s'43

3s+

36+

37+

38+

3e+

30+

31+

32+

33*

34+

o.L)

9.26

9.11

8.97

8.83

8.69

8'56

8.43

8.31

8.19

8.07

7.96

7.85

7.74

7.63

7.53

7.43

7.34

7.24

7-15

7.06 I s0 5.65 4.71 I 70 4.04

4.63 I 71 3.98

4'55 I 72 3.92

6.57 I s3 s.33 4.48 I 73 3.87

6.42 | s4 5'23 4.41 I 74 3.82

6'28 I ss s.13 4.3s I 7s 3.77

6.14 I 56 s.04 4.28 I 76 3'72

6.01 | s7 4.96 4.22 I 77 3.67

s'8e I s8 4.87 4.16 178 362

5.77 I s9 4.79 4'10 I 79 3.57

cT9

www.bsaunitsingles.com

CT CONVERSION TABLES

PINTS TO LITRES

POUNDS PER S@L'ARE INCH TO

KILOGRAMS PER SAUARE CENTIMETRE

012345678

..t-

14'

.284

.426

.568

.710

.8s2

.994

1.'t36

1.279

1.420

1.563

1.705

1.846

1.989

2.131

2.273

2.4't5

2-557

2.699

2.841

2.983

3'125

3.267

3.841

3.552

3.'t2s

3.836

3.978

4.12A

4.6F4

4.404

4.546

4.688

4'830

'4.972

GALLONS (tMPER|AL) TO LTTRES

o1234567I9

45.46A

90-919

136.379

1 81 .838

227.298

272'757

318.217

363.676

409-136

4.546

50'005

9s.465

140.924

186.384

231.843

277.303

322.762

368.222

413.681

9.092

54.551

100.01 1

145.470

1 90.930

236.389

281.849

327.308

372.768

418.227

13.638

59.097

104.557

150.016

195.476

240-935

286.39s

331.854

377.314

422.773

18.'184

63.643

000'000

000.000

200.022

245.481

290'941

336'400

381.860

427.319

22.730

63.1 89

113.649

1 59.108

204.568

250.027

295.487

340.946

386.406

431.86s

27.276

72.73s

118.195

163.645

209-114

254.573

300'033

345.492

390.952

436.411

31.822

77.28'l

122.741

1 68.200

713.660

259.119

304.579

3s0.038

395.498

440.957

36.368

81.827

127.287

172.746

218'206

263.605

309.1 25

354.s84

400.044

44s.503

40.9't4

86.373

13'1 '833

177.292

222-752

268.211

313.671

359.'t 30

404.590

450.049

0123456 7 89

0.703

1.406

2.109

2.812

3.515

4.218

4.92',1

5.624

6'328

0.070

0-773

1-476

2'179

2.883

3.586

4'289

4.992

5.695

6.398

0-141

0.844

1-547

2.250

2.9s3

3.656

4-359

5.062

5.76s

6.468

c.211

0.914

1-617

2.320

3.023

3.726

4'429

5.132

5.835

6.538

0.28'l

0.984

1.687

2.390

3.093

3.797

4.500

5.203

5.906

6.649

0.352

't.055

'1.7s8

2.46',1

3.164

3.867

4.570

5.273

5-976

6.679

0.422

1.125

1.828

2-531

3-234

3.937

4.640

s.343

6.046

6.749

0.492

1.195

1.898

2.601

3.304

4.007

4.711

5.414

6.117

5.820

0.562

1.266

1.969

2.672

3.375

4.078

4-781

5.484

6.187

6'890

0.633

1.336

2.039

2.742

3.445

4.',t48

4.85'l

5.554

6.257

6.960

Printed in England by

Warwick Printing Co. Ltd.,lWarwick

cT10

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