Subaru Robin Power Products Eh12 2 Eh17 Eh25 Users Manual ES1154

CONTENTS

Section Title

1

.

2

.

3

.

4

.

5

.

6

.

7

.

8

.

Page

4-1

4-2

4-3

4-4

4-5

4-6

4-7

4-8

4-9

4-1

0

4-1

1

4-1

2

4-1 3

4-1 4

4-1

5

4-1 6

4-1 7

I.

SPECIFICATIONS

~~ ~ ~~~ ~ ~ ~~ ~~ ~~~ ~~~~ ~~ ~~~ ~ ~

EH

12-2

EH12-2B EH12-2DS

EHl2-2D EH12-2BS

Model

TY

Pe

Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal

P.T.O.

Shaft, Gasoline Engine

Bore

X

Stroke

Piston Displacement

60

x

43 rnm (2.36

x

1.57 in.)

121

cm3

(7.38 cu.in.)

I

Max.

Torque

Nem (kaf*m)/rDm 15 (1

52)

/1300 7.5 (0.76) /2600

Direction

of

Rotation

Cooling system

Counterclockwise

As

Viewd From

P.T.O.

Shaft Side

Forced Air Cooling

Valve Arrangement

Lubrication

Overhead Valve

Splash Type

~~ ~ ~~~~~ ~~ ~

Lubricant

Capacity of Lubricant

0.6

L

(0.16

U.S.

gal.)

~~ ~

Automobile

Oil

SAE

#20, #30 or 1 OW-30

;

Class SE, SF

or

higher

I

Carburetor

I

Horizontal Draft, Float Type

I

Fuel

I

Automobile Gasoline

~~~~~~~ ~~

310 g/KW*h (230 gr/HP*h) At Continuous Rated Output

~ ~~~

I

Fuel Feed System

I

Gravity Type

Fuel Tank Capacity

Flywheel Magneto (Solid State) Ignition System

3.6 L (0.95

U.S.

gal.)

I

Spark Plug NGK BGES

Charging Capacity

Starter

Recoil Starter Starting System

12V

-

1.3A

-

12V

-

1.3A

-

Recoil and Electric

Starter

Recoil and Electric

Recoil

Starter

I

Speed Reduction 2:l Cam Shaft Drive

Governor System Centrifugal Flyweight System

Dry

Weight

Length

15.5 kg (34.2Ib.)

I

18.0 kg (39.7 Ib.)

I

15.0 kg (33.1 Ib.)

I

17.5 kg (38.6Ib.)

299 mm (1 1.77 in.)

I

299 mm (1 1.77 in.)

I

297 mm (1 1.69 in.)

I

297 mm(ll.69 in.)

330mrn (12.99in.)

366 mm (14.41 in.)

341 mm (13.43in.)

366 mm (14.41 in.)

-1-

EH17-2

EH17-2B EH17-2DS

EH17-2D

EH17-2BS

Model

TY

Pe

Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal

P.T.O.

Shaft, Gasoline Engine

Bore

X

Stroke

~~ ~~ ~~ ~~~~ ~ ~

67

x

49

mrn

(2.64

X

1.93 in.)

172 cm3 (10.50 cu.in.)

.

Compression Ratio 8.5

Output 2.6

(3.5)

/3000 2.9 (4.0) /3600

2.6

(3.5)

/

1500 2.9 (4.0)

/

1800

Continuous

Kw

(HP)/rpm 4.4 (6.0) /4000

4.4 (6.0) /2000

Max.

Torque

Nom

(kgf*m)/rpm 21.4 (2.1 8)

/

1300

1

0.7

(1

-09)

/

2600

I I

Direction of Rotation Counterclockwise

As

Viewd From P.T.O. Shaft Side

I

Cooling system

I

Forced

Air

Cooling

I

Valve Arrangement

I

~~

Overhead Valve

I

Lubrication

I

Splash Type

~ ~~ ~~ ~

Lubricant

Capacity of Lubricant

Horizontal Draft, Float Type Carburetor

0.65

L

(0.17

U.S.

gal.)

~~~~~~~ ~

~_____

_____

~ ~

Automobile Oil

SAE

#20, #30

or

1OW-30

;

Class

SE,

SF

or higher

Fuel

310g/KW-h (230 gr/HP*h) At Continuous Rated Output

Fuel Consumption Rate

Automobile Gasoline

Fuel Feed System

3.6

L

(0.95

US.

gal.)

Fuel Tank Capacity

Gravity Type

Flywheel Magneto (Solid State)

Spark

Plug

12V

-

1.3A

-

12V

-

1.3A

-

Charging Capacity

NGK

B6HS

I

Starting System

Speed Reduction

Centrifugal Flyweight System Governor System

-

2:l

Cam Shaft Drive

Dry

Weight

Dimensions

16.5 kg (36.4 Ib.)

341

rnm

(13.43in.:

330

rnm

(12.99in.)

341

rnrn

(13.43in.) 330

mm

(12.99in.)

Width

299 mm(ll.77in.)

299

mm

(1 1.77 in.) 301

mrn

(1

1.85 in.)

301

mm

(1 1.85 in.)

Length

18.5 kg

(40.8

Ib.)

16.0 kg (35.3

Ib.)

19.0

kg (41.9

Ib.)

Height 380mm (14.96in.) 380rnm (14.96in.) 380mm (14.96in.) 380rnm (14.96in.:

-2-

~~~~~~ ~~ ~

EH25-2

6

EH25-2DS

EH25-2D

EH25-26s

Model

TY

Pe

Air-Cooled, 4-Cycle, Single-Cylinder, Horizontal P.T.O. Shaft, Gasoline Engine

Bore

x

Stroke

Piston Displacement

75

X

57

mm

(2.95

X

2.24 in.)

251

cm3 (15.31 cu.in;)

Compression Ratio

8.5

output 4.0

(5.5)

/3000 4.7 (6.4) /3600

4.0

(5.5)

I1

500

4.7 (6.4)

/

1800

Continuous

Kw

(HP)hm 6.3

(8.5)

/4000

6.3

(8.5)

/2000

Max.

Torque

Nom (kgf*m)/rpm 33.1 (3.38)

/

1300 16.6 (1.69)

/

2600

Direction

of

Rotation

I

Counterclockwise As Viewd From P.T.O. Shaft Side

Cooling system

Valve Arrangement

Forced Air Cooling

Overhead Valve

Lubrication

Automobile Oil SAE #20, #30 or

1

OW-30

;

Class

SE,

SF

or

higher Lubricant

Splash Type

Capacity of Lubricant

1

.O

L

(0.26

U.S.

gal.)

Carburetor

Fuel

Horizontal Draft, Float Type

Automobile Gasoline

~ ~~~ ~ ~ ~ ~~~~~

Fuel Consumption

Rate

Fuel Feed System

31

0

g/KW*h (230 gr

/

HP-h)

At Continuous Rated Output

Gravity Type

Fuel Tank Capacity

Flywheel Magneto (Solid State)

Ignition System

6.0

L

(1

59

U.S.

gal.)

Spark Plug

12V

-

1.3A

-

12V

-

1.3A

-

Charging Capacity

NGK

B6HS

Starting System Recoil Starter

Starter

Recoil and Electric

Recoil

Starter

1

Starter

Recoil and Electric

Speed Reduction

I

2:l Cam Shaft Drive

I

-

Governor System

I

Centrifugal Flyweight System

Dry Weight

332mm(l3.07in.) 332mm (13.07in.)

333mm (13.11 in.)

I

Length

27.0 kg (59.5

Ib.)

23.0

kg

(50.7

Ib.)

28.0 kg (61.7 Ib.)

24.0 kg (52.9

Ib.)

~~~ ~~

Dimensions

440mm

(17.32in.) 440mm (17.32in.)

440mm

(17.32in.)

440mm

(17.32in.)

Height

380mrn (14.96in.) 380mm (14.96in.)

380mm

(14.96in.)

380mm (14.96in.)

Width

-3-

2-1

MAXIMUM OUTPUT

The maximum output is the output of an engine with its throttle valve fully opened under the condition

that all the moving parts are properly

worn

in after the initial break-in period.

A

new engine may not produce full maximum output while its moving parts are still not broken-in.

2-2

CONTINUOUS

RATED

OUTPUT

The continuous rated output is the output

of

an engine at optimum governed speed which is most

favorable from the view point

of

engine’s life and fuel consumption.

When the engine

is

installed

on

a certain equipment,

it

is

recommended that the continuous output

required from the engine be kept below this continuous rated output.

2-3

MAXIMUM

TORQUE

The maximum torque

is

the torque at the output shaft when the engine is producing maximum output at

certain revolution.

-4-

2-4

PERFORMANCE CURVES

8

0

EHlPD,

B

HP

kW

4

3

+

3

l2

n

+

0

3

1

0

2

1

for

B

type

2000

3000

(1

000)

(1

500)

REVOLUTION

-

r.p.m.

4000

(2000)

-5-

0

EH17D,

6

for

B

tvDe

(1

000)

REVOLUTION

-

r.p.m.

N.m

kgfam

3000

4000

(1

500)

(2000)

-6-

EH25D,

B

HP

8

7

t:

$4

&

I-

2

1

0

r

I I

I

I I

I

"

"-

I

1

"

MAXIMUM

TORQUE

AL\

I

I I

kW

I

MAXIMUM

HORSEPOWER

'(NET)

I

-6

5

4

I

RECOMMENDED

I

i

N.m

kgf-m

16.5

(33)

15.5

(31)

14.5

(29)

1.7

(3.4)

1.6

(3.2)

1.5

(3.0)

1.4 (2.8)

c

2000

3000

'

4000

(1

000)

(1

500)

(2000)

REVOLUTION

-

r.p.m.

-7-

3.

FEATURES

,

1.

The overhead valve design offers

a

compactness, light weight and ideal combustion characteristics

2.

An

optimum lubrication and better tilted operation thanks to upright cylinder design.

3.

A crossflow arrangement

of

intake and exhaust ports ensures stable performance under high ambient

temperature.

4.

The automatic decompressiom system lightens

the

recoil pull force by

40%

comparing to the

conventional

SV

engines.

5.

An easy operation thanks to integrated engine control system.

Improved throttle mechanism

is

adopted for easy starting.

6.

Combustion and mechanical noises have been analyzed acoustically and improved for better tonal

quality and lower engine noise.

7.

Optimally designed reciprocating parts reduce the vibration level of the engine.

EH25-2

engine

equips single through-balancer shaft as an option.

resulting in more power from Iess fuel and prolonged engine life.

4.

GENERAL DESCRIPTION

OF

ENGINE COMPONENTS

4-1

CYLINDER

AND

CRANKCASE

The cylinder and crankcase

is

single piece aluminum

diecasting. The cylinder liner, made of special cast

iron,

is

molded into the aluminum casting.

The crankcase has a mounting surface. on the output

shaft side, where the main bearing cover is attached.

4-2

MAIN

BEARING

COVER

The main bearing cover

is

an aluminum diecasting,

which

is

mounted on the output shaft side of the

crankcase.

Remove the main bearing cover to inspect the inside

of

the engine.

The pilots and bosses are machined on the cover for

direct mounting of the engine onto such machines

as

generators and pumps.

Oil gauge (fillers) are on both sides of the cover for

easy maintenance.

Fig.

4-1

OIL GAUGE

OIL

GAUGE

/"-

\

/"

Fig.

4-2

-8-

4-3

CRANKSHAFT

The crankshaft is forged carbon steel, and

the

crank

The output end of the shaft has a crankshaft gear, and

balancer gear for

EH25-2

which are pressed into

position.

W

pin is induction-hardened.

44

CONNECTING

ROD

AND

PISTON

The connecting rod is an aluminum alloy diecasting,

and

its

large and smalI ends function as bearings.

The piston

is

an aluminum alloy casting, and carries

two compression rings and one

oil

ring.

4-5

PISTON RINGS

The piston rings are made

of

special cast iron.

The profile of the top ring

is

barrel face and the

second ring has a tapered

face.

The

oil

ring consists

of

a cutter ring and a

coil

expander for better sealing and less oil consumption.

B

TYPE

D

TYPE

Fig.

4-3

I

fig.

4-4

TOP

RING

SECOND

RING

OIL

RING

fig.

4-5

-9-

4-6

CAMSHAFT

The camshaft

for

the D-type engine is made

of

special cast iron and camshaft gears are casted to-

gether

in

one piece.

Both sides of the shaft fit into the plane bearings on

the crankcase and main bearing cover.

The camshaft for the B-type engine is made of

forged carbon steel and also functions as PTO shaft.

The cam gear

is

press fitted on the shaft and the ball

bearings are employed

on

both sides for supporting

the shaft.

4-7

VALVE ARRANGEMENT

The intake valve is located

on

flywheel side

of

the

cylinder head.

The hard alloy valve seats axe molded in the cylinder

head and stellite is fused to the exhaust valve face.

The cylinder baffle leads cooling air to the exhaust

valve area for the optimum cooling.

4-8

CYLINDER HEAD

The cylinder head is an aluminum die casting which

utilizes wedge

type

combustion chamber

for

the

highest combustion efficiency.

B

TYPE

D

lYPE

Fig.

4-6

n

/

INTAKE

Fig.

4-7

Fig.

4-8

-

10

-

4-9

GOVERNOR SYSTEM

The governor

is

a centrifugal flyweight type which

ensures constant operation at the selected speed

against load variations.

The governor gear with governor weights is installed

on the main bearing cover.

4-10

COOLING SYSTEM

The large fins on the flywheel provide sufficient

cooling air capacity

for

the inlet and exhaust area

and cylinder.

The cylinder baffle helps the cooling air flow effi-

ciently.

GOVERNOR

GEAR

/

Fig.

4-9

4-1

1

LUBRICATION

All the rotating and sliding parts are splash-

lubricated by the oil scraper on the connecting rod.

I

OIL

SCRAPER

Fig.

4-10

4-1

2

-IGNITION SYSTEM

The ignition system is a transistor controlled mag-

neto ignition system which cosists of a flywheel and

an ignition coil with a built in transistor.

This system has an ignition timing advance for easy

starting.

Fig.

4-1

7

-

11

-

4-13

CARBURETOR

The engines are equipped with a horizontal draft

carburetor that has a float controlled fuel system and

a

fixed

main jet.

The carburetors are calibrated carefully for easy

starting, good acceleration, low fuel consumption

and sufficient output.

4-14

AIR

CLEANER

The air cleaner is a

single

urethane foam element system.

As

an option, heavy duty type with

a

double

element type is available.

CLEANER

CASE

Single

element type

Fig.

4-

1

3-

I

4-15

BALANCER

(Option

for

EH25-2)

Unbalanced inertia force

is

balanced by the balancer

which rotates at the same speed with the crankshaft

to effectively reduce vibration.

CLEANER COVER

Double element type

Fig.

4-

13-2

BALANCER

I

-

Fig.

4-14

-

12-

4-16

DECOMPRESSION

SYSTEM

An

automatic decompression mechanism which

opens exhaust valve before the piston reaches com-

pression top

is

assembled on the camshaft for easy

starting.

AUTOMATIC

DECOMPRESSOR

SYSTEM

Fig.

4-14

-

13-

4-1

7

SECTIONAL

VIEW

OF

ENGINE

FUEL

TANK

FLYWHEEL

MAIN

BEARING

COVER

-

14-

a

ROCKER

ARM

PUSH ROD

-

15

-

5.

DISASSEMBLY

AND

REASSEMBLY

5-1

PREPARATIONS AND SUGGESTIONS

1)

When disassembling the engine, memorize the locations

of

individual parts

so

that they can be

reassembed correctly. If yor are uncertain

of

identifying some parts, it

is

suggested that tags be

attached to them.

2)

Have boxes ready to keep disassembed parts by group.

3)

To

prevent losing and misplacing, temporarily assemble each group

of

disassembed parts.

4)

Carefully handle disassembed parts, and clean them with washing oil

if

necessary.

5)

Use

the correct tools in the correct way.

5-2

SPECIAL

TOOLS

Tool

No.

Use

Tool

209

-

95004-

07

For

pulling

off

the flywheel

EH25-2

Flywheel

puller with

bolt

Market

parts

For

pulling

off

the flywheel

EH12-2,

EH17-2

Flywheel puller

/"-

FLYWHEEL PULLER FLYWHEEL

PULLER

Fig.

5-1

-

16

-

5-3

DISASSEMBLY PROCEDURES

Step

Tool

Remarks Procedures

Part

to

remove

I

1

14mm

box

wrench

Be careful

not

to

lose the

(1)

Remove

oil

drain

plug

and drain oil. Oil drain

(2)

To

discharge oil quickly, remove oil gasket.

gauge.

GASKET

I

Fig. 5-2

DRAIN

PLUG

-

17

-

Step

Tool

Remarks

Procedures

Part

to

remove

I

2

Fuel

tank

1

(1)

Close

fuel

valve.

(2) Disconnect fuel hose between fuel strainer

and carburetor.

(3)

Remove fuel

tank

from cylinder

head.

M6X14mm bolt

*.--

4pcs. (EH12-2,17-2)

M8X20mm bolt

0-

4pcs. (EH25-2)

~ ~ ~~ ~~

Wipe

off

spilt

fuel

thoroughly.

1

Omm

(1

2mm)

socket

wrench

(EH12-2,

17-2)

(EH25-2)

FUEL

HOSE

-*

Fig.

5-3

-

18

-

Step

I

Part

to

remove

I

Procedures

I

Remarks

I

Tool

Recoil starter

(1)

Remove recoil

from

blower housing.

M6

X

8mm

flange

bolt

-

4pcs.

1

Omm

box

wrench

I

housing

5

Oil sensor

(Option)

I

(1)

Remove blower housing

from

crankcase.

M6X

i2mm

flange bolt 4pcs.

lOmm

box

wrench

(1)

Remove oil sensor probe.

Be

careful not

to damage stick and sensor since these are

sensitive and

an

erratic operation

may

result.

BLOWER

HOUSING

Fig.

5-4

-

19

-

)art

to remove

Muffler cover,

Muffler and

Exhaust pipe

cover

Procedures

(1) Remove muffler cover

and

exhaust pipe

cover.

M6X

lOmm flange

bolt

0..

Spcs.

(2) Remove

muffler

from crankcase and

cylinder head.

M8 nut 2pcs.

M6

X

12mm

flange bolt

-

1

PC.

M8X

16mm flange

bolt

-

1 pc.

(EH25-2)

(EHl2-2,17-2)

I

Remarks

Be careful

not

to

lose

muffler gasket.

Tool

8mm, lOmm

and

12mm socket wrench

M8

NUT

:

2

pcs.

MUFFLER

COVER

c

Fig.

5-5

-

20.-

Control

box

and Electric

(Option)

Procedures

Tool

Remarks

(1)

Disconnect wires.

blue

1

(diode rectifier

)

light blue

1

(diode rectifier

)

black

***

1

(magnetic switch)

(2)

Remove black wires from electric starter.

(3)

Remove control

box.

12mm socket wrench

(4)

Loosen

two

bolts

and

remove electric

Fastened together with

fuel

tank.

starter.

M8

bolt 2pcs.

to

-

21

-

Head cover

L

Air

cleaner

Procedures

Tool

Remarks

(1)

Remove head cover from crankcase.

1

Omm

M6

X

12mm flange bolt

1

pc. socket wrench

(1)

Remove cleaner cover and cleaner

lOmm

Fastened together with

element.

M6

flange

nut

2pcs.

socket wrench

carburetor.

1

(2)

Remove cleaner case.

c

.GASKET

\

CLEANER CASE

c

Fig.

57

-

22

-

Step

10

-

11

12

-

13

-

Part

to

remove

I

~

Procedures

Governor

lever,

Governor rod

and Governor

spring

Carburetor

(1) Unhook governor spring from speed

control lever.

(2) Remove governor lever from governor

shaft.

M6X30mm

bolt and washer

-e

lpc.

(3)

Detach governor lever, governor rod and

rod spring from carburetor.

(1)

Remove carburetor from

intake

pipe.

Bolt and washer on

governor lever

only

needs to be loosened.

1

Omm

socket wrench

Speed control (1) Remove stop plate, friction plate and

lever speed control lever.

M6

X

14mm flange bolt

.

-

-.

1

PC.

lOmm

socket wrench

Intake pipe (1) Remove

intake

pipe from cylinder head. Be careful not

to

lose 10mm, 12mm

M6 flange nut

-

2pcs. (EH12-2,17-2) insulator and gasket. socket wrench

M6

X

25mm

flange bolt

-

1 pc.

M8 X28mm bolt and washer

(EH12-2, 17-2)

-.-a

~PCS.

(EH25-2)

STOP

PLATE

M6

FLANGE NUT

:

2

PCS.

(EH12-2, 17-2) GASKET (INSUMTOR)

M6

FLANGE BOLT

1

PC.

(EH12-2, 17-2)

FRICTION PLATE

M8

BOLT

and

WASHER

:

3

pcs.

(EH25-2)

SPEED CONTROL LEVER ARBURETOR

ROD

SPRING

GOVERNOR

ROD

GOVERNOR

LEVER

M6

BOLT

and

WASHER

:

1

PC.

Fig.

5-8

-

23

-

14

Ignition coil

l-

“

”

Procedures

I

Remarks

(1)

Disconnect ignition

plug cap

and

remove

ignition coil

from

crankcase.

M6X25mm bolt and washer

...-

2pcs.

(1)

Remove starter pulley

from

flywheel.

Place socket wrench on flywheel fastening

nut and strike

tip

of the lever

with

hammer. Refer to the illustration below.

(See Fig.

5-9.)

14mm nut lpc. (EHl2-2, 17-2)

18mmnut

****

1pC. (EH25-2)

Do not place bar

or

screw

driver in flywheel

fin

to

loosen flywheel nut.

I

1

9mm(EH12-2,17-2)

24mm(EH25-2)

socket wrench

c

(EH12-2,

17-2)

(EH25-2)

Fig.

5-70

-

24

-

Fig.

5-9

Step

Too

I

Remarks

Procedures

Part

to

remove

16

Flywheel puller

Use flywheel puller

as

(1)

Remove flywheel

from

crankshaft.

Flywheel

(2)

Remove

key

from crankshaft. illustrated below.

(See

Fig.

5-12.)

(See Fig.

5-1

1.)

~

17

(1)

Remove charge

coil.

Charge

coil

I

(Option)

M6

X

25mm

Screw

2pcs.

18

21

mrn

(1)

Remove spark

plug

from

cylinder head.

Spark

plug

socket wrench

Fig.

5-1

1

FLYWHEEL

-

25

-

step

19

20

~~~ ~

Part

to

remove

Rocker cover

Cylinder head

Procedures Remarks

(I)

Remove rocker cover

from

cyIinder head.

(2)

Remove gasket. (rocker cover)

M6X 12mm flange bolt

..-.

4pcs.

(1)

Remove cylinder head from crankcase.

M8x65mm flange bolt

....

4pcs.

MIOX75mmflangebolt

--.-

4pcs.

(EH12-2,

17-2)

(EH25-2)

(2)

Detach cylinder head gasket from cylinder

(3)

Remove

push

rods.

head.

M6

FLANGE

BOLT

:

4

pcs.

Tool

1

Omm

socket

wrench

12mm, 14mm

socket wrench

Fig.

5-74

-

26

-

Step

21

-

Part

to

remove

Main bearing

cover

Procedures

(1) Remove main bearing cover fastening

bolts.

M6X30mm bolt and washer

-

8pcs.

M8X30mm bolt and washer

-.-.

8pcs.

(2)

Remove main bearing cover using plastic

(EH

12-2, 17-2)

(EH25-2)

hammer.

(See Fig.

5-15)

I

!

I

-

L

Fig.

5-15

Remarks

Be careful

not

to

damage

oil

seal.

MAIN

M6

BOLT

and

WASHER

:

8

pcs.

(EH12-2,

17-2)

M8

BOLT

and

WASHER

:

8

pcs.

(EH25-2)

1

Omm,

12mm

socket wrench

L

Fig.

5-1

6

-

27

-

I

Step

22

-

23

Part

to

remove

,

Procedures

1

Cam shaft and

Balancer shaft

(Option for

EH25-2)

Tappet

(1)

Remove cam shaft from crankcase.

(2)

Remove balancer shaft.

(Option for

EH25-2)

(1)

Remove tappets

from

crankcase.

Remarks

Tool

t

To

prevent

tappets

from

getting damaged, put the

crankcase upside down.

(See

Fig.

5-17.)

Put a

tag

on

tappets to

identify intake and

exhaust.

,.

-

28

-

Step

I

Partto

remove

I

Procedures

24

~~~

Connecting

(1)

Remove connecting rod bolt after scraping

rod and

off

carbon from cylinder and piston.

Piston M6

X

34mm flange bolt 2pcs. (EHI 2-2)

M7X37mm flange bolt 2pcs. (EH17-2)

M8x46mm

flange bolt 2pcs. (EH25-2)

(2) Remove connecting rod cap.

(3)

Remove connecting

rod

from upper side

of

crankcase after rotating crankshaft

so

that piston comes up to top dead center.

,

i

~

25

Piston and

(1)

Remove clips and piston pin.

Piston rings

(2)

Remove piston from connecting rod.

(3) Remove piston

rings

from piston.

CLIP

PISTON RING

PISTON

,

/-

c

/

PISTON PIN

CONNECTING

ROD

&N\

CONNECTING

Remarks

Tool

lOmm

socket wrench

Do

not damage the

smaller end of connecting

rod.

Do

not expand or twist

piston

rings.

,

I

M6

FLANGE BOLT

:

2

PCS.

(EH12-2)

M7 FLANGE BOLT 2

PCS.

(EH17-2)

M8

FLANGE

BOLT

2

PCS.

(EH25-2)

Fig.

5-79

-

29

-

Step

Too!

Remarks

Procedures

Part

to

remove

26

Be

careful

not

to

damage

(1)

Remove

crankshaft

tapping

at the

Crankshaft

flywheel

end.

oil

seal.

c

Fig.

5-20

c

CRANKSHAIT

(D

type)

c

fig.

5-21

-

30

-

Step

27

'art

to

remove

Intake valve

and Exhaust

valve

Procedures

(1)

Loosen

nut

and remove bolt (pivot).

(2)

Remove

rocker

arms.

(3)

Press down spring retainer, take

out

collet

valve, and then remove spring retainer

and valve spring

(4)

Remove intake

and

exhaust valve.

.(See

Fig.

5-23.)

Remarks

Inspect valves, valve

seats and guide.

Do

not remove valve

guides unless they are

worn beyond the limit

shown

in

page

58.

/

INTAKE

VALVE

EXHAUST

VALVE

Fig.

5-24

.

M6

NUT

Tool

-

31

-

5-4

REASSEMBLY

PROCEDURES

0

PRECAUTIONS

FOR

REASSEMBLY

1)

Clean parts throughly before reassembly.

Pay most attention to cleanliness

of

piston, cylinde :r, crankshaft, connectin

g

rod and bearings.

Scrape

off

all carbon deposits from cylinder head, piston top and piston ring grooves.

Check

lip

of

oil

seals.

Replace oil

seal

if

the

lip is damaged.

Apply oil

to

the lip before reassembly.

4)

Replace all the gaskets with new ones.

5)Replace keys,

pins,

bolts, nuts, etc.,

if

necessary.

6)Torque bolts and nuts to specification referring to the

“TORQUE

SPECIFICATIONS”.

7)Apply oil to rotating and sliding portions.

8)

Check and adjust clearances

and

end plays where specified

in

this manual.

54-1

CRANKSHAFT

(1)

Install crankshaft on crankcase lapping the shaft

with polyvinyl tape to avoid damage to oil seal.

(2)

Install

woodruff

key for the flywheel on critnk-

shaft.

54-2

PISTON

AND

PISTON

RINGS

(1)

Install the oil ring first, then second ring and top

ring.

Spread the ring only far enough to slip over the

piston and into the correct groove.

Use

care not

to distort the ring.

Install the second ring with the punched mark

“R”or

“N”

beside the gap on the top side. (See

Fig.

5-29.)

Fig.

5-26

OPEN

ENDS

OF

PISTON

RING

/

Fig-

5-27

-

32

-

Fig.

5-28

5-4-3

PISTON

AND

CONNECTING,

ROD

(1)

When installing the piston on the connecting rod,

place the valve rcess

of

the piston crown as

shown in the illustration to the

"MAG"

side of the

connecting rod.

Apply oil to the small end

of

the connecting rod,

piston and piston pin before installation.

Be sure to use clips on the both

end

of the piston

to

secure the pin in position.

"R"

MARK

(EH12-2,EH17-2)

"N"

MARK

(EH25-2)

Fig.

5-29

I

"MAG"

SIDE

VALVE

RECESS

Fig.

5-30

-

33

-

(2)

Install the piston and connecting rod assembly

into the cylinder.

Use a piston ring compressor

to

hold

the piston

rings.

Place

“MAG”

side of the connecting rod on the

magneto side

of

the crankcase.

[NOTES]

(1)

Apply

enough oil to piston rings, connecting

rod bearings

and

cylinder bore before

assembly.

(2)

Set gaps of the piston rings

90

degrees

apart

from each other before assembly.

PISTON RING COMPRESSOR

CONNECTING

ROD

CRANKCASE (FLYWHEEL

SIDE)

Fig.

5-3

1

SECOND

RING

./=<

0

RING

Fig.

5-32

54-4

CONNECTING

ROD

(1)

Turn crankshaft

to

bottom dead center, lightly tap

top

of

the piston until large end

of

the rod meet

crankpin.

(2) Install the connecting rod cap to the connecting

rod

matching alignment marks.

Torque

connecting

rod

bolts

to specification.

M6

X

34

mm

flange bolt 2pcs.

(EH12-2)

M7

X

37

mm

flange bolt

-0..

2pcs.

(EH17-2)

M8

X

46

mm

flange

bolt

2pcs.

(EH25-2)

CONNECTING

ROD

BOLT TIGHTENING TORQUE

I

EH

1

2-2

EH

17-2

EH25-2

1

17-1

9.5

Nom

22-27

N*m

(3)

Check

for

free movement

of

connecting rod

by turning crankshaft slowly.

ALIGNMENT MARK

Fig.

5-33

-

34

-

5-4-5

BALANCER

SHAFT

(Option

for

EH25)

Install balancer shaft aligning the timing mark

on

the

balancer shaft gear and the balancer gear on the

crank shaft as shown in the illustration.

Incorrect timing

of

the gears

will

cause

matfunction

of

the engine and may result in

damage due to interference

of

the parts.

5-4-6

TAPPET AND CAMSHAFT

(1)

Oil the tappets and install them in their original

position.

TIMING

MARKS

Fig.

5-34

Push in fully to avoid damage during the installation

of

the camshaft.

Align the timing mark on the crankshaft gear with the timing mark on the camshaft

and

install the

camshaft in the crankcase

as

shown in the illustration.

(2)

Lubricate the bearing surfaces of camshaft.

I

Incorrect valve timing will cause engine's

I

malfunction.

m'

5-4-7

ADJUST CRANKSHAFT AND CAMSHAFT END PLAY

(1)

Adjust end play to the specified values using the proper spacer.

The

proper spacer may be determined following manner.

MAIN BEARING

COVER

7

I

\"I

A2

I

t

I

GASKET

t

7

+

11

t

II

0.3

I

CRANKSHAFT

B1

82

Fig.

5-35

-

35

-

5-4-7-1

CRANKSHAFT

END

PLAY

(For

D

type

and

B

type)

(1)

Measure the depth “Al” (From the mating surface to the inner race of the ball bearing.)

(2)

Measure the height “Bl”

(From

the mating surface to the crank gear.)

(Al+

0.3)

-

Bl=SIDE CLEARANCE

(mm)

(SIDE CLEARANCE)

-

0.2=THICKNESS OF CRANKSHAFT

SHIM

(mm)

(A+

0.012”)

-

Bl=SIDE CLEARANCE

(in)

SIDE

CLEARANCE

-

0.008”=THICKNESS

OF

CRANKSHAFT

SHIM

(in)

5-4-7-2

CAMSHAFT

END

PLAY

(Model

B=2:1

Reduction

type

only)

(1)

Measure the depth

“AT’

(From the mating surface to the inner race of the camshaft bearing.)

(2)

Measure the height

“B2”

(From

the mating surface to the camgear inner

boss.)

(A2+

0.3)

-

B2=SIDE CLEARANCE (mm)

(SIDE CLEARANCE)

-

0.2=THICKNESS

OF

CAMSHAFT

SHIM

(mm)

(A2+ 0.012”)

-

B2=SIDE CLEARANCE (in)

SIDE

CLEARANCE

-

0.008”=THICKNESS

OF

CAMSHAFT

SHIM (in)

Following are availalbe spacer shims.

EH12-2, EH17-2 type

CRANKSHAFT CAMSHAFT

T=0.6

rnm

(0.024”)

T=0.6 mm (0.024”)

SPACER

SHIMS

T=l

.O

mrn

(0.039’3

T=l

.O

mm

(0.039”)

T=0.8

mm

(0.031

”)

T=0.8

mm

(0.031

”)

-

EH25-2

type

r-“-

SPACER

SHIMS

I

CRANKSHAFf(For

D

type)

1

CRANKSHAFT(For

B

type)

I

CAMSHAFT

I

T=0.6

mm

(0.024”)

T=l

.O

rnrn

(0.039”)

T=3.1

rnm

(0.1227

T=l

.O

mm

(0.039’3 T=0.8 mm

(0.031’)

T=2.9

mm

(0.1

147

T=0.8 mm

(0.031

”)

T=0.6

mm

(0.024”)

T=2.7

mm

(0.1

06”)

-

36

-

MAIN

Fig.

5-36

(2)

Lubricate the

oil

seal

and

bearing surfaces.

Add

a

light film

of

oil

on

the

main

bearing cover face

to

hold the gasket in place.

Place spacers chosen at procedure

(1)

on crankshaft and camshaft.

Use an oil seal guide when installing the main bearing cover to avoid damaging the seal.

Tap the cover into place with a soft hammer.

Main bearing cover EH12-2, 17-2

M6

X

30

mm bolt and washer

....

8

pcs.

EH25-2

M8

X

30

mm bolt and washer

.-e-

8

pcs.

Tightening torque

(EH12-2,17-2)

Tightening torque

(EH25-2)

17-1

8.5

Nom

80-1

00

kgwn

170-1

90

kgocrn

12.5-13.5

ftelb

-

37

-

5-4-8

CYLINDER HEAD

(1)

Clean carbon and gum deposits from the valves, seats, ports and guides. Inspect the valves, valve

(2) Replace valves that are badly burned, pitted or warped.

(3)

When installing the valves in the cylinder head, oil the valve stems and insert them into the valve

guide.

Then place the cylinder head

on

a flat

table,

install the valve springs, spring retainers

and

collet

valves.

(4)

Valve guides should be replaced when the valve stem clearance exceeds specifications (See

"SERVICE

DATA").

Draw the valve guides out and press the new guides in.

Refer to"SERV1CE

DATA"for

clearance specifications.

After replacing the valves and guides, lap valves

in

place until a uniform ring shows around the face

of the valve. Clean valves and wash cylinder head thoroughly.

Tighten four flange bolts evenly in three steps by the following tightening torque:

Cylinder head

M8

X

65

mm flange bolt

-

4

PCS.

(EH12-2, 17-2)

seats and valve guides.

(5)

Install cylinder head to cylinder with new head gasket.

M10

X

75

mm

flange bolt

-

4

pcs.

(EH25-2)

Tightening torque

(EH12-2,

17-2)

1

st

step final step

2nd step

5

Nom

100

kgcm

50

kgwn

23-26

Nm

10

Nom

17-30

ft-lb

7.2

ft-lb

3.6

ft-lb

230-270

kgcm

Tightening torque

(EH25-2)

1

st

step

final

step

2nd step

9.8

Nom

100

kgecrn

33.3-41.2

Nom

19.6

Nom

24.6-30.4

ft*lb

14.5

ft4b

7.2

ft-lb

340-420

kg-cm

200

kgcm

n

54-9

ROCKER

ARMS

AND

PUSH

RODS

(1)

Insert push rods into crankcase.

Put push rod tip in the hollow

of

tappet top.

(2)

Apply oil to the rocker arms and assemble them to the cylinder head using pivot bolt and guide plate.

5-4-10

VALVE

CLEARANCE ADJUSTMENT

(1)

Position the piston at the top dead center of the compression stroke. The top dead center may be

obtained by placing the key slot

on

the power take

off

shaft

to

:

I

12

o'clock

I

10 o'clock

I

EH12-2B,17-2B,25-2D

I

EH12-2D,17-2D,25-2B

-

38

-

(2)

Loosen the nut under the rocker arm and turn the bolt

(pivot)

to adjust the clearance between the

rocker arm and the valve stem end.

Tighten the nut under the rocker arm.

I

Valve clearance

I

0.08-0.1

2

mm

0.0031

-0.0047

in.

I

Check operation

of

valves

by

turning crankshaft.

Recheck valve clearance.

(3)

Install rocker cover and gasket.

Rocker cover

M6

X

12

mm bolt

.-..

4

pcs.

5-4-1

1

SPARK PLUG

Install spark plug

to

the cylinder head.

Spark

plug

:

EHl2-2

:

NGK

B6ES

EH17-2,25-2

:

NGK

B6HS

Tightening

torque

New

spark

plug

Retightening

11.8-1

4.7

N*m

2216-26.5

Nom

~____

120-150

kg-cm

[

230-270

kg-crn

8.7-1

0.9

fblb

16.6-1

9.5

fblb

5-4-12

FLYWHEEL MAGNETO

(1)

Install the charge coil to the crankcase. (Option)

Be careful not

to

pinch coil wire between charge

coil and crankcase.

(2)

Put the woodruff key in the key way of crank-

shaft.

Wipe off oil and degrease thoroughly from the

tapered portion

of

the crankshaft and the flywheel

center hole.

Tighten the flywheel nut with the starter pulley.

(3)

Install the flywheel to crankshaft.

Fig.

5-38

Fig.

5-39

-

39

-

1

Tightening

torque

I

59-63

N-m

I

600-650

kgocm

I

43-47

ft*lb

I

54-13

IGNITION

COIL

Install the ignition coil

to

the crankcase.

Adjust the air

gap

between the ignition

coil

and the

flywheel using a thickness gauge (filler gauge) and

tighten the bolts.

Tightening torque

8.8-10.8

Nom

I

90-1

10

kgecrn

6.5-8.0

ft4b

A

Fig.

5-40

5-4-14

INTAKE PIPE,

lNSULATOR

(1)

Install the intake pipe to the cylinder head with gasket.

EH12-2,

17-2

M6 flange nut

..---.....-.......-.

2 pcs.

M6

X

25mm flange bolt

.-.......

1

PC.

EH25-2 M8

X

28mm bolt and washer

3

pcs.

Tightening torque

9.8-1

3.7

Nm

7.2-10.1

ft4b

100-1

40

kgocm

Then put the gasket and the insulator on the intake pipe.

54-15

CARBURETOR

Install the gasket and the carburetor to the intake pipe.

54-16

GOVERNOR

SYSTEM

(1)

Connect the governor lever and the throttle lever

on carburetor with governor rod and rod spring.

Install the governor lever

on

the governor shaft.

(2)

Install the speed control lever to the cylinder

head.

GOVERNOR

LEVER

Fig.

5-4

1

-

40

-

(3)

Connect the speed control lever and the governor lever with the governor spring. The governor spring

’

(4)

Turn the speed control lever all the way toward the high speed position and make sure that the throttle

(5)

Turn the governor shaft clockwise all the way using a screw driver, and tighten the lock bolt and nut.

should be hooked to the number

2

hole on the speed control lever for the regular specifications.

Refer to the illustrations below. (See Fig.

5-42.)

valve

in

the carburetor is at the wide open position.

(See

Fig.

5-43.)

For the generator applications, there are two different governor springs existing according to the speed

setting of the engine. The governor springs may be distinguished

by

the following table.

The

governor spring employed on the

6OHz

application is same as the one from the standard specifi-

cations.

r

I

SPEED

CONTROL

LEVER

GOVERNOR

SPRING

\\

‘l)t--”

GOVERNOR

LEVER

Fig.

5-43

N

;

SPRING

WOUND

EH

1

2-2

EH25-2

EHl7-2

50

Hz

(3600

rpm)

(3000

rpm)

(3600

rpm)

(3000

rprn)

(3600

rpm)

(3000

rprn)

60

Hz

50

HZ

60

Hz

50

HZ

60

Hz

e

t

8.7

(0.34”)

9.6

(0.38”)

10.7

(0.42”)

8.1

(0.32”) 9.1

(0.35”)

D

t

43

(1

-73

t

38

(1.5‘7

t

49

(1.9’7

~

I

Color

Silver

Gold

Silver

Gold Silver Gold

~~~

-

41

-

54-17

AIR CLEANER

Install the air cleaner gasket and the cleaner case and tighten them with 2-M6 flange nuts.

Then install the element and the cleaner cover.

5-4-1

8

HEAD COVER

Install the head cover

to

the cylinder head.

M6

X

12mm flange

bolt

..a-

1

PC.

54-19

MUFFLER, MUFFLER COVER

and

EXHAUST

PIPE

COVER

Install the muffler to the cylinder head.

M8

flange

nut

....

2

pcs.

230-270

kgcm

16.6-1

9.5

ft-lb

Then tighten the muffler bracket portion.

M6

X

12mm flange bolt

--.a

1

PC.

(EH12-2, 17-2)

M8

X

16mm flange bolt

1

PC.

(EH25-2)

Install the muffler cover and exhaust pipe cover.

M6

X

10mm flange bolt

e-..

5

pcs.

54-20 BLOWER

HOUSING,

RECOIL

Install the blower housing and the recoil. Insert the high tension cord from the ignition coil into the notc

of

the

blower

housing

so

that

not

to

pintch the

cord.

54-21 FUEL TANK

Install the fuel tank. Connect the fuel strainer and the fuel inlet

on

carburetor with the fuel hose.

M6

X

14mm bolt and washer

-.--

4

pcs. (EH12-2,17-2)

M8

X

20mm bolt and washer

4

pcs.

(EH25-2)

:h

-

End of the reassembly

-

42

-

c

5-5

BREAK-IN

OPERATION

B

An

engine that has been completely overhauled by being fitted with a new piston, rings, valves and

connecting rod should be throughly

RUN-

IN

before being put back into service.

Good bearing surfaces and running clearances between the various parts can only be established by

operating the engine under reduced speed and loads for

a

short period of time.

While the engine

is

being tested, check

for

oil

leaks.

Make final carburetor adjustment and regulate the engine operating speed.

Steps

10

min

3600

rpm

No

load

Step

3

10

min

3000 rpm

No

load

Step

2

10

min

2500 rpm

No

load

Step

1

Time

Engine

speed

Load

1

Step

4 EH12-2

EH17-2

EH25-2

1

1.5

KW

b.OHPI

1

3600 rpm

1.OKW

1.4HP

2.4KW 3.2HP 30 min

Step

5

EH12-2

EH25-2

EH17-2

1

$:A

f::

1

3600 rpm 60 min

4.7KW

6.4HP

6.

IGNITION

SYSTEM

6-1

TYPE

OF

IGNITION SYSTEM

EH12-2

employs the

U.

T.

C.

I.

(Universal type Transistor Controlled Ignition) pointless ignition system.

EH17-2

and

EH25-2

have the

T.

I.

C. (Transistor, Igniter, Circuit) pointless ignition system.

AS

optional parts, these ignition system may be implemented with lamp.coi1, charge coil and excitor coil.

6-2

BASIC

THEORY

To

ensure the easy startability

of

the engine, the step advancing ignition timing system is incorporated in

the ignition coil. This system enables the engine

to

have basically two different ignition timings

according to the engine speed. Following are the explanation how the system works.

1)

At lower speed

of

the engine

Rotation

of

the flywheel induces current

I,,

as this current flows through the base terminal

of

the

power transister,

it

is activated

and

the current

IZ

starts flowing.

As

the engine reaches the ignition timing, the ignition timing control circuit for the lower engine speed

is activated and lets the current

L

flow through the base terminal of the power transistor.

This generates the collector current

L

which will bypass the current

11

and abruptly shut

off

the current

IZ

because the power transistor is turned

off.

This sudden current change generates a big voltage

on

the secondary side of the ignition coil and

which sparks the spark plug.

8

-

43

-

2)

At the higher engine speed

Rotation

of

the flywheel generates the current

I1

as this current

flows

through the base terminal

of

the

power transistor,

it

is activated and the current

IZ

starts

of

flow.

As

the engine reaches the ignition timing, the ignition timing control circuit

for

the higher engine

speed

is

activated and provides the base current

Is

to

the power transistor. This current induces the

collector current

It,

and will bypass the current

I,

to shut down the current

IZ

abruptly because the

power transistor is turned

off.

This sudden current change generates a big voltage

on

the secondary side

of

the ignition coil and

which

will

spark the spark plug.

The ignition timing control circuit for the higher engine speed is activated sooner than the controI

circuit for the lower speed and not activated when the engine speed

is

in a lower range.

7

cn

3

h

ELECTRONIC ADVANCING

FLYWHEEL

MAGNETO

SYSTEM

(B.T.D.C.)

15”k

I

,

500

1000

2000

3000(r.p.m.)

ENGINE

REVOLUTION

Fig.

6-2

(b)

-

44

-

6-3

WIRING

DIAGRAM

STANDARD

Stop

switch

Connector

Black

>

Spark

Plug

Ignition

Coil

Flywheel

ElNGlNE WITH ELECTRIC STARTER

DIODE

RECTIFIER

I

""""_""""

I

L

12VOLT

BATTERY

MtNIMUM

24

AMP.HR.

Fig.

6-3

-

45

-

7.

AUTOMATIC

DECOMPRESSION

SYSTEM

EH12-2, 17-2, 25-2 engines are employing the automatic decompression system

as

a standard feature.

This enables easy and light start of the engine.

The automatic decompression system releases the compression

of

the engine by lifting up the exhaust

valve at the cranking. Following are the explanation using

type

“D”

engine

as

a sample how the system

works. The components

of

the systems are different for the type

“D”

and type

“B”

engines, however, the

principle

of

the function

is

same.

At the end

of

the compression process, the release lever lifts

up

the tappet which in turns opens up the

exhaust valve slightly

to

release the compression. The release lever has a flyweight

on

its end and another

end

of

the lever

is

a

crescent

cam.

When the engine is cranked, the crescent cam projects the camshaft cam profile and lifts up the tappet

because the gravity force on the weight is larger than the centrifugal force

on

the weight.

i

TAPPET,

I

LEVER

CRESCENT

EXHAUST

Fig.

7-1

When the crank speed reaches up to

a

certain revolution, the crescent cam

is

retracted into the camshaft

cam profile because the centrifugal force applied onto the flyweight becomes larger than the gravity force

and the weight.and

is

shifted

to

the position shown in the illustration.

FLYWEIGHT

CRESCENT

CAM

EXHAUST

CAM

EXHAUST

-Y-T3

CAM

CAMSHAFT

LEVER

,”-

Fig.

7-2

-

46

-

8.

CARBURETOR

B

8-1

OPERATION

AND

CONSTRUCTION

8-1

-1

FLOAT

SYSTEM

The float chamber is located below the carburetor body

and, with a float and a needle valve, maintains a

constant fuel level during the engine operation.

The fuel flows from the fuel tank into the float chamber

through the needle valve. When the fuel rises to

a

specific level, the float rises, and when

its

buoyancy

and fuel pressure are balanced, the needle valve shuts

off the fuel, thereby keeping the fuel at the predeter-

mined level.

FI

Fig.

8-1

PILOT

OUTLET

\

BY-PASS,"""

,

[""

"-""

+=""~Z

I

PILOT

AIR

JET

AT

I

1

MAIN

AIR

JET

\

k"""

II

'""""i=r""J'

-\

MAIN

JET

Fig.

8-2

-

47

-

8-1-2 PILOT SYSTEM

The pilot system feeds the fuel to the engine during idling and low-speed operation.

/"l

The .fuel

is

fed through the main jet

to

the pilot jet, where it

is

metered, and mixed with the air metered

by the pilot air jet.

The fuel-air mixture is fed to the engine through the pilot outlet and the by-pass.

At

the idling speed, the fuel

is

mainly fed from the pilot outlet.

8-1-3

MAIN

SYSTEM

The main system feeds the fuel to the engine at medium-and high-speed operation.

The fuel

is

metered by the main jet and fed to the main nozzle. The air metered by the main air jet is

mixed with the fuel through the bleed holes in the main nozzle, and the mixture is atomized out of the

main bore. It

is

mixed again with the air taken through the air cleaner into an optimum fuel-air mixture,

which

is

supplied to the engine.

8-14

CHOKE

The choke may be used for easy start when engine

is

cold. When the engine is cranked with a closed

choke, the negative pressure applied to the main nozzle increases and draws more fuel accordingly this

starting up the engine more easily.

8-2

DISASSEMBLY AND REASSEMBLY

Apart from mechanical failures, most

of

carburetor troubles are caused by an incorrect mixing ratio,

which may arise mainly due to

a

clogged up air or fuel passage in jets,

or

fuel level variations.

In

order to

assure proper flow

of

air and fuel, the carburetor must be kept clean at a11 times. The carburetor

disassembly and reassembly procedures are as follows.

8-2-1 THROITLE SYSTEM

(1)

Remove the philips screw

(1)

and throttle valve

(2),

(2)

The spring

(4)

can be taken out by removing the

*

Be

careful not

to

damage the throttle valve rim.

and pull

out

the throttle shaft

(3).

throttle stop screw

(5).

8-2-2

CHOKE

SYSTEM

(1)

Remove the philips screw

(6)

and choke valve

(7),

and pull out the choke shaft

(8).

(2)

When reassembling the choke shaft, make sure that

the cutout in the choke valve faces the main air jet.

Meanwhile, when reassembling set the rings

(9)

and

(10)

at the right position.

8-2-3

PI

LOT SYSTEM

(1)

Remove

the

pilot jet

(ll),

using proper tools to

(2)

Reassembly

avoid damage to

it.

Tighten the pilot jet securely. Otherwise, the fuel

may leak, causing engine malfunction.

123

It

7%

u

\

21

-@

13*

18

0

12

"----&

Fig.

8-3

-

48

-

8-2-4

MAIN

SYSTEM

(1)

Remove the bolt(l2)and take out float chamber body(l3).

B

(2) From the body

(14)

remove the main nozzle

(15),

and then remove the main jet

(16)

and guide holder

(17) from the main nozzle

(15).

(3)

Reassembly

a)Fasten the main jet securely to the body. Otherwise, the fuel may become too rich and cause engine

b)The bolt tightening torque is 70kg-cm. Be sure to set the gasket

(19)

and washer

(18)

for chamber

malfunction.

(13).

8-2-5

FLOAT

SYSTEM

(1)

Pull out the float pin (20) and remove the float

(21)

and then remove the clip

(22)

and needle valve

(23).

If the needle valve needs to be replaced, replace it with rubber needle.

When cleaning the jets, be sure

to

use

compressed air to blow them clean.

Never use a drill or a wire because of possible damage of the orifice which will considerably affect

fuel

flow.

(2) When removing the needle valve and float, gently tap the reverse side using the rod more slender

than the

float

and

remove, since the float pin

is

calked

to

the carburetor body.

-

49

-

9.

STARTING

SYSTEM

9-1

RECOIL

STARTER

Equipments to be prepared

:

Driver, Pinchers (Pliers) and Protective Glasses

WARNING

starting the disassembly;

make

sure to wear

the

protective glasses.

9-1-1

Disassembly

Steps

I

/

(1)

Setting off the spring power

-1

:

Hold

the starter knob and extract the starter

1

rope.

-2

:

Extract the rope fully and hold the rope

so

that the knob

of

the rope in the reel makes a

dicrect line with the rope guide.

-3

:Push

and hold the reel with the thumbs of

both hands firmly

so

that

the

rope will not be

wound back.

(Fig.

9-1)

-4:

Pull off the knot of the rope out

of

the reel,

unfasten the knot and pull it off to the direc-

tion

of

the starter knob.

(2

persons required)

-5

:

By

controling the reel with the thumbs

of

both

hands, unwind the rope gently until the rota-

tion

of

the

reel

stoos.

I

Fig.

9-1

r

The spring power is at its most when the rope is fully extracted. Therefore, do not abruptly put

off

your

hand nor loosen the pressure of your finger unintentionally.

(2)

Setting

the

attachments

off

(Fig.

9-2)

-

1

:

Fix

the case and loosen the set-screw.

-

2

:

Put off the set-screw, the latchet guide, the

friction

spring and the latchet in the same

order from above.

(3)

Setting the reel off (Fig.

9-2)

-

1

:Push

the reel lightly

so

that it

will

not float

up. Move the reel clockwise and counter-

clockwise about a quarter circle for several

times until it moves smoothly.

-

2

:

Pull up the reel gradually and slowly and put

it off from the case.

-

3

:

In

case the spring

in

the reel is close

to

pop

up,

redo the steps

of

(3)-1

and

(3)-2

again.

-

WARNING

Do

not drop or shake the reel and put

it

on

a level table

because there

is

a spring set in the disassembled reel.

Disassembly is complete.

-

50

e-

SET

SCREW

RATCHET

GUIDE

FRICTION

SPRING

RATCHET

'

REEL

Fig.

9-2

WARNING

Before starting the assembly, make sure to wear the protective glasses.

9-1-2

Assembly

Steps

GREASE PASTING

(1)

Setting the reel into the case.

-1

:Paste grease on the case. (Fig.

9-3)

-2

:

Adjust the position

of

the inner end

of

the

spring, which is set in the reel. (Fig.

9-4)

-3

:Hold

the reel

so

that the shafthook part and

the inner end

of

the spring are hooked to-

gether. Drop the reel gently from above into

the case.

Fig.

9-3

-4

:

Move the reel slightly counter-clockwise and

make sure the spring

is

hooked.

THE

END

TOUCHES

THE

RIB

OF

THE BEARING

Fig.

9-4

(2)

Setting

the

attachments

-1

:

Set the latchet into the reel. (Fig.

9-5)

THE LATCHET

IS

KEPT AT CLOSE-POSITION

Fig.

9-5

-2

:

Holding the latchet, set the

sub-assembly. (Fig.

9-6)

latchet-guide

SET

SCREW

RATCH ET

GUIDE

I

cb-'

FRICTION

/

SPRING

LATCHET

GUIDE

SUB-ASSEMBLY

Fig.

9-6

-

51

-

-1

i

Push the latchet-guide lightly by hand

so

that

the latchet guide won’t move and tighten the

set-screw.

(4)

Storing the spring-power.

-1

:Hold the case tight and using both hands,

wind

up

the reel counter-clockwise

6

times.

-2:

Set

the ree to keep the position, whereby the

rope hole

of

the reel and the rope guide make

a

direct line. (Fig.

9-7)

(3)

Tightening

the set-screw.

Fig.

9-7

WARNING

The spring power

is

at

its most when the

reel

is

being wound. Therefore,

do

not abruptly put

off

your

hand

nor

loosen

the

pressure

of

your finger unintentionally.

(5)

Setting the rope.

(2

persons required)

-1

:

Set the end

of

the rope through the

rope

guide and the rope hole

of

the reel and pull the end about

20

cm out

of

the reel. (Fig.

9-7)

-2

:

Fasten the end

of

the rope.

-3

:

Put the rope into the reel, whereby make sure

that the rope will not float up.

(Fig.

9-9)

-4:

Hold the rope firmly with one hand at the

position about

50

cm

from the rope guide

and

keep the rope slightly pulled

so

that the rope

will not be wound

in.

-5

:Put the hand

off

the reel gently and put the

rope back slowly obeying the winding power

of

the spring until the knob reaches the rope

guide.

Assembly is complete.

ABOUT

20mm

F;g.

9-8

Fig.

9-9

-

52

-

(6)

Test the operation of

the

recoil starter to see

if

the rope recoils satisfactorily and the ratchets project

and retract properly. Mount the recoil starter to the engine.

(7)

If the spring escapes from the reel when disassembling the recoil, hook the outer end of the spring

onto the notch

of

the reel and rewind the spring into the housing.

(8)

Lubricate the rotating parts, sliding parts

and

spring with heat resistant grease or mobile oil when

reassembling the recoil and prior

to

long term storage.

-

53

-

IO.

TROUBLESHOOTING

The following three conditionts must be fulfilled for satisfactory engine start.

1.

The cylinder filled with

a

proper fuel-air mixture.

2.

Good compression in the cylinder.

3.

Good spark, properly timed, to ignite the mixture.

The engine cannot be started unless these three conditions are met. There are also other factors which

make engine start difficult, e..

g.,

a heavy load on the engine when it is about

to

start at low speed, and a

high back pressure due to

a

long exhaust pipe.

The most common causes of engine troubles are given below

:

10-1

STARTING

DIFFICULTIES

10-1-1

FUEL

SYSTEM

(1)

No

gasoline in the fuel tank

;

or the fuel cock closed.

(2)

The carburetor

is

not choked sufficiently especially when the engine

is

cold.

(3)

Water, dust

or

gum in the gasoline iterfering the fuel flow to the carburetor.

(4)

Inferior grade gasoline or poor quality gasoline not vaporized enough to produce the correct fuel-air

mixture.

(5)

The carburetor needle valve is held open by dirt or gum. This trouble can be detected as the fuel

flows out of the carburetor when the engine is idling. (Overflow)

This trouble may be remedied by lightly tapping the float chamber with the grip of a screwdriver or

the like.

(6)

If the carburetor overflows, excessive fuel runs into the cylinder when starting the engine, making the

fuel-air mixture too rich

to

burn. If this happens, remove the spark plug, and turn the starting pulley a

/"-

few turns in order

to

let the rich fuel-air mixture

out

of the spark

plug

hole into the atmosphere. Keep

the choke valve open during this operation. Dry the spark plug well, screw it into place, and try

to

start again.

10-1

-2

COMPRESSION SYSTEM

If starting difficultes and loss

of

power are not due to the fuel system or ignition system, the followings

must be checked for possible lack

of

compression.

Engine inside is completely dried up because of a long period

of

storage.

Loose or broken spark plug. This causes a hissing noise made by mixture gas running out of cylinder

in compression stroke during cranking.

Damaged head gasket or loose cylinder head.

A

similar hissing noise is produced during compression

stroke.

Incorrect Valve clearance

If the correct compression

is

not obtained even after remedying the above, disassemble the engine and

check further as follows

:

a) Valve stuck open due to carbon or gum on the valve stem.

b)If the piston rings are stuck on the piston, remove the piston and connecting rod from the engine.

Clean or replace the parts.

-

54

-

10-1-3

IGNITION SYSTEM

Check the followings for lack

of

sparks.

(1)

Wires

of

the ignition coil, spark plug

or

contact breaker disconnected.

B

(2)

Ignition coil damaged and shorted.

(3)

Spark plug cable wet or soaked with oil.

(4)

Spark plug dirty or wet.

(5)

Spark plug electrode gap incorrect.

(6)

Spark plug electrodes are connected or bridged.

(7)

Incorrect spark timing.

10-2

ENGINGE MISFIRES

Incorrect spark plug electrodge gap. Adjust it to anywhere between

0.6

and

0.7mm.

Ignition cable worn and leaking.

Sparks weak.

j.lj

Ignition wire connections loose.

(5)

Water in gasoline.

(6)

Insufficient compression.

10-3

ENGINE

STOPS

(1)

Fuel tank empty. Water, dirt, gum, etc. in gasoline.

(2)

Vapor lock,

i.

e., gasoline evaporating in the fuel lines due to overheat around the engine.

(3)

Vapor lock

in

the fuel lines

or

carburetor due to the use of too volatile winter gas in the hot season.

(4)

Air

vent hole

in

the fuel tank cap plugged.

(5)

Bearing parts seized due to lack

of

oil.

0

(6)

Magneto or ignition coil faulty.

,

104

ENGINE OVERHEATS

(1)

Crankcase oil level low. Add oil immediately.

(2)

Spark timing incorrect.

(3)

Low grade gasoline is used, or engine is overloaded.

(4)

Cooling air circulation restricted.

’

(5)

Cooling air path misdirected causes loss

of

cooling efficiency.

(6)

Cylinder head cooling fins clogged up with dirt.

(7)

Engine operated in an enclosed space without sufficient cooling air

(8) Exhaust gas discharge restricted,-or carbon deposits in the combustion chamber.

(9)

Engine running on low-octane gaoline detonates due

to

heavy load at low speed.

-

55

-

10-5

ENGINE

KNOCKS

(1)

Poor quality gasoline.

(2)

Engine operating under heavy load

at

low

speed.

(3) Carbon

or

lead deposits in the cylinder head.

(4)

Spark timing incorrect.

(5)

Loose

connecting rod bearing due

to

wear.

(6)

Loose piston pin due

to

wear.

(7)

Cuases

of

engine

overheat.

10-6

ENGINE

BACKFIRES

THROUGH CARBURETOR

(1)

Water or dirt

in

gasoline,

or

low-grade gasoline.

(2)

Intake valve stuck.

(3)

Valves overheated,

or

hot

carbon particles in the combustion chamber

(4)

Engine cold.

-

56

-

11.

INSTALLATION

Engine life, ease

of

maintenance and inspection, frequency of checks and repairs, and operating

cost

all

I)

depend on the way in which the engine

is

installed. Review the following instructions carefully for

installing the engine.

11-1 INSTALLING

When mounting the engine, carefully examine

its

position, the method

of

connecting

it

to

a

machine, the

foundation, and the mehtod of supporting the engine.

When determining its mounting position, in particular, make sure that gasoline and oil can easily be

supplied and checked, the spark plug can easily be checked, the air cleaner can easily be serviced, and

that the

oil

can easily be discharged.

11

-2

VENTILATION

Fresh air

is

necessary for cooling the engine and burning the fuel.

In the case the engine

is

operated under a hood or in a small room, temperature rise in the engine room

can cause vapor lock, oil deterioration, increased

oil

consumption, loss of power, piston seizure, shorter

engine life, etc., making it impossible to operate the engine properly. It is necessary, therefore, to provide

a duct or baffle

to

guide cooling air to the engine to prevent recirculation

of

he hot air used for engine

cooling, and temperature rise of the machine.

Keep the engine room temperature below

50°C

even in the hottest period

of

the year.

11-3 EXHAUST GAS DISCHARGE

Exhaust gas

is

noxious. When operating the engine indoors, be sure to discharge the exhaust gas

outdoors.

If

a long exhaust pipe is used in such a case, the internal resistance increases causing

loss

of

engine power. Thus pipe inside diameter must be increased in proportion to exhaust pipe length.

Exhaust pipe: Less than 3m long, pipe inside diameter 30mm,

Less than 5m

long,

pipe inside diameter 33mm.

11-4 POWER TRANSMISSION

TO

DRIVEN MACHINES

11 -4-1 BELT

DRIVE

Take the following notes into consideration.

*

V-belts are preferable to flat belts.

*

The driving shaft of the engine must be parallel to the driven shaft

of

the machine.

*

The driving pulley

of

the engine must be in line with the driven pulley of the machine.

*

Install the engine pulley as close to the engine as possible.

*

If

possible, span the belt horizontally.

*

Disengage the load when starting the engine.

If no clutch is used, use a belt tension pulley or the like.

11-4-2 FLEXIBLE COUPLING

B

When using a flexible coupling, runout and misalignment between the driven shaft and engine shaft must

be minimized. Runout and misalignment tolerance are specified by the coupling manufacturer.

-

57

-

12.

SERVICE

DATA

“STD”

in

the

following

table

is

the parts dimension from the brand new engine or the spare parts.

Whereas, “Limit”

shows

the maximum allowance for the parts to

be

used

on

the engine.

If

the measurement exceeds

beyond

the “Limit”, the part needs to be replaced and/or repaired.

12-

1

CLEARANCE DATA AND LIMITS

r

Flatness

1

Valve seat contact

width

I

Valve

guide inside dia.

IN.

EX.

EH

1

2-2

EH17-2

EH25-2

r

Unit

:

mrn

(in)

EH

12-2

/

17-2

/

25-2

STD

LESS

THAN

0.05

(0.002)

0.7

-

1

.O

(0.028

-

0.039)

5.500

-

5.51

8

(0.21

65

-

0.21

72)

6.035

-

6.053

(0.2376

-

0.2383)

Limit

0.1

(0.004)

2.0

(0.079)

5.65

(0.2224)

6.1

5

(0.2421)

-

58

-

Unit:

mm

(in)

EH

1

2-2

EH

1 7-2

I

ITEM

Lmit

STD

Lm

it

To

be rebored

when the

lifference

letween

ma.

snd min.

of

jiameter

.cached

to 0.1

:0.004).

-0

be rebored

vhen the

lifference

letween

ma.

nd rnin.

of

jiameter

eached to 0.1

0.004).

CYLINDER

Inside dia.

57.000

-

67.01

9

2.6378

-

2.6385)

60.000

-

60.01

9

(2.3622

-

2.3630)

STD

60.250

-

60.269

(2.3720

-

2.3728)

67.250

-

67.269

2.6476

-

2.6484)

1

st

reboring

2nd

reboring

Ditto Ditto

60.500

-

60.51 9

(2.381

9

-

2.3826)

67.500

-

67.51

9

2.6575

-

2.6582)

0

Roundiness after reboring.

0

Cylindricity after reboring.

LESS

THAN

0.01

(0.004)

LESS

THAN

0.01

(0.004)

LESS

THAN

0.01

5

(0.0006)

LESS

THAN

0.01

5

(0.0006)

PISTON

0

Piston size

(At

skirt in thrust

direction) 59.96

-

59.98

(2.3606

-

2.3614:

59.87

(2.3571)

66.98

-

67.00

12.6370

-

2.6378)

66.89

(2.6335)

'STD

60.1

2

(2.3669)

67.23

-,

67.25

:2.6469

-

2.6476:

67.1

4

(2.6433)

60.21

-

60.23

(2.3705

-

2.371 3

1

st

01s

60.37

(2.3768)

67.48

-

67.50

(2.6567

-

2.6575:

67.39

(2.6531)

60.46

-

60.48

(2.3803

-

2.381

1

2nd

01s

I

-

59

-

Unit:

mm

(in)

ITEM

2Y

LIN

DER

inside dia.

B

Roundiness

after

reboring.

Cyiindricity after reboring.

PI

STON

0

Piston size (At

skirt

in

thrust

direction)

STD

1

st

reboring

2nd

reboring

STD

1

st

01s

2nd

OJS

r

EH25-2

STD

75.000

-

75.01

9

2.9528

-

2.9535)

75.250

-

75.269

2.9626

-

2.9633)

75.500

-

75.51 9

2.9724

-

2.9732)

LESS

THAN

0.01

(0.004)

LESS

THAN

0.01

5

(0.0006)

74.98

-

75.00

(2.9520

-

2.9528:

75.23

-

75.25

(2.961

8

-

2.9626

75.48

-

75.50

(2.9717

-

2.9724

Lmit

-0

be rebored

/hen

the

ifference

letween

ma.

md

min.

of

liameter

eached to

0.1

0.004).

Ditto

74.89

(2.9484)

75.1

4

(2.9583)

75.39

(2.9681)

-

60

-

Uni

:

rnm

(in)

T

EH17-2

ITEM

STD

Limit

STD

Limit

0

Ring groove side clearance

0.030

-

0.075

(0.001 2

-

0.0030)

0.1

5

(0.006)

0.15

(0.006)

0.035

-

0.080

:0.0014

-

0.0031)

0.030

-

0.075

(0.001 2

-

0.0030)

0.1

5

(0.006)

0.025

-

0.070

(0.0010

-

0.0028)

0.1

5

(0.006)

t

2nd

0.020

-

0.075

(0.0008

-

0.0030)

0.1

5

(0.006)

0.01 0

-

0.065

(0.0004

-

0.0026)

0.1

5

(0.006)

Oil ring

Piston pin hole

m

12.991

-

13.002

(0.51 15

-

0.51

19)

13.035

(0.51

32)

15.991

-

16.002

(0.6296

-

0.6300)

16.035

(0.631

3)

0

Piston pin outside dia.

12.992

-

13.000

(0.51

15

-

0.51

18)

12.960

(0.51

02)

15.992

-

16.000

(0.6296

-

0.6299)

15.960

(0.6284)

Clearance between piston and

cylinder at skirt area.

0.01

5

-

0.074

(0.0006

-

0.0029)

0.25

(0.01

0)

0.015

-

0.074

(0.0006

-

0.0029)

0.25

(0.01

0)

Piston ring end gap

TOP

2nd

0.2

-

0.4

(0.008

-

0.01

6)

1.5

(0.0591

)

0.2

-

0.4

(0.008

-

0.01

6)

1.5

(0.0091)

0.2

-

0.4

(0.008

-

0.01

6) 1.5

(0.0591

)

0.05

-

0.25

(0.0002

-

0.01

0)

1.5

(0.0591)

oil ring

-

61

-

Unit:

mrn

(in)

1

Ring groove

side

clearance

I

Piston pin hole

~rn

Piston pin outside

dia.

Clearance between

piston

and

cylinder at skirt area.

I

Piston ring

end

gap

2nd

Oil

ring

TOP

2nd

oil

ring

EH25-2

STD

0.050

-

0.090

1.0020

-

0.0035)

~ ~ ~ ~~~~~

0.030

-

0.070

).0012

-

0.0028)

0.010

-

0.065

1.0004

-

0.0026)

17.991

-

18.002

1.7083

-

0.7087)

17.992

-

18.000

3.7084

-

0.7087)

0.025

-

0.064

0.0001

-

0.0025)

0.1

-0.3

(0.004

-

0.01

2)

0.1

-

0.3

(0.004

-

0.01

2)

Limit

0.1 5

(0.006)

0.1

5

(0.006)

0.1

5

(0.006)

7

8.035

(0.71

00)

17.960

(0.7071

)

0.25

(0.01

0)

1.5

(0.0591)

1.5

(0.0591)

-

62

-

Unit:

mm

(in)

ITEM

EH

1

2-2

STD

Limit

ZONNECTING

ROD

D

Big end inside dia.

26.000

-

26.01

3

(1

-0236

-

1.0241)

26.1

(1.0276)

Clearance between big end

and crankpin

0.020

-

0.046

(0.0008

-

0.001

8)

0.2

(0.008)

I

0

Small end inside dia.

13.08

(0.51

50)

13.01

0

-

13.021

(0.51 22

-

0.51 26)

0

Clearance between small end

and

piston

0

Big

end side clearance

0.01

0

-

0.029

(0.0004

-

0.001

1)

0.1

2

(0.0047)

0.1

-

0.7

(0.004

-

0.028)

1

.o

(0.040)

I

CRANKSHAR

0

Crankpin outside dia.

25.967

-

25.980

(1.0223

-

1.0228)

25.85

(1.01

77)

0

Journal dia.

Dl,

D2

24.988

-

24.997

(0.9839

-

0.9841)

1

-

63

-

m-

ITEM

-

EH

1

7-2

STD

CONNECTING

ROD

0

Big

end

inside dia.

Clearance between

big

end

and crankpin

Small end inside dia.

Clearance between

big

end

and crankpin

Small end inside dia.

0

Clearance between

small

end

and piston pin

Big

end side clearance

I

CRANKSHAFT

0

Journal

dia.

Unit:

mm

(in)

30.000

-

30.01

6

(1.1811 -1.1817)

0,020

-

0.049

(0.0008

-

0.001

9)

16.01

0

-

16.021

(0.6303

-

0.6308)

0.01

0

-

0.029

(0.0004

-

0.001 1)

0.1

-

0.7

(0.004

-

0.028)

29.967

-

29.980

(1.1798

-

1.1803)

Dl,

D2

24.988

-

24.997

(0.9838

-

0.9841)

-

64

-

Limit

30.1

(1.1850)

0.2

(0.008)

16.08

(06331

)

0.1 2

(0.0047)

1

.o

(0.040)

29.85

(1.1752)

lTEM

F

EH25-2

~

STD

0

Clearance between

big

end

and crankpin

0

Small end inside dia.

t

I

0

Clearance between small end

and piston pin

0

Big end side clearance

I

CRANKSHAFT

0

Journal dia.

-

I

34.000

-

34.01

6

(1.3386

-

1.3392)

0.025

-

0.057

(0.0010

-

0.0022)

18.01

0

-

18.021

(0.7091

-

0.7095)

0.01

0

-

0.029

(0.0004

-

0.001

1)

0.1

-

0.7

(0.004

-

0.028)

33.959

-

33.975

(1.3370

-

1.3376)

Dl

D2

1

TYPE

Z9.991 -30.000/29.988-29.99;

:1.1807

/

(1.1

806

-1.1

81 1) ;-1.1810)

3

TYPE

:1.1807

27.991 -30.0001

(1

o,

-1.1811)

'27.988-27.99

:-1.1022)

..

Limit

34.1

0

(1

.3425)

0.2

(0.008)

Unit:

mm

(in)

w

-

18.08

(0.71 18)

0.1

2

(0.0047)

1

.o

(0.040)

33.85

(1.3327)

-

65

-

Unit

:

mrn

(in)

EH12-2

/

EH17-2

ITEM

STD

Limit

CAMSHAFT

0

Cam

height

29.6

-

29.8

(1.165

-

1.173) 29.45

(1.1 59)

IN.=.

CAMS

I

Journal outside dia.

"D"

type

16.973

-

16.984

(0.6682

-

0.6687) 16.95

(0.6673)

Dl

14.973

-

14.984

(0.5895

-

0.5899) 14.95

(0.5886)

D2

VALVE

Valve stem outside dia.

5.440

-

5.455

(0.21

42

-

0.21

48) 5.35

(0.21

06)

IN.

5.426

-

5.444

(0.21 36

-

0.21 43) 5.35

(0.21 06)

EX.

0

Clearance between valve

stem

dia. and

valve guide

0.045

-

0.078

(0.001 8

-

0.0031)

0.3

(0.01

2)

IN.

0.056

-

0.092

(0.0022

-

0.0036)

0.3

(0.01

2)

Ex.

Valve clearance

IN

./EX.

(cold)

0.08

-

0.1

2

(0.0031

-

0.0047)

-

66

-

Unit:

mm

(in)

ZAMSHAFT

Cam height

a

Journal outside dia.

'D"

type

ITEM

IN.=.

CAMS

Dl

VALVE

Valve stem outside dia.

Clearance between valve stem dia. and

valve guide

"P

1

.. .. ..

..

Valve clearance

D2

IN.

Ex.

IN.

EX.

IN

./EX.

(cold)

EH25-2

I

Limit

30.6

-

30.8

(1.205

-

1.213) 30.45

(1.199)

24.967

-

24.980

(0.9823)

(0.9830

-

0.9835)

24.95

14.973

-

14.984

(0.5886)

(0.5895

-

0.5899)

14.95

5.975

-

5.990

(0.2303)

(0.2352

-

0.2358)

5.85

5.960

-

5.975

(0.2303)

(0.2346

-

0.2352)

5.85

0.045

-

0.078

(0.01

2)

(0.001 8

-

0.0031) 0.3

0.060

-

0.093

(0.01

2)

(0.0024

-

0.0037)

0.3

0.08

-

0.1

2

(0.0031

-

0.0047)

-

67

-

ITEM

TAPPET

0

Stem outside dia.

0

Guide inside

dia.

0

Tappet

guide clearance

VALVE

SPRING

FREE

LENGTH

Unit:

rnrn

(in)

1

STD

7.960

-

7.975

(0.31

34

-

0.31

40)

8.000

-

8.01

5

(0.31

50

-

0.31

56)

0.025

-

0.055

(0.001

0

-

0.0022)

Limit

-

68

-

Unit: mrn

(in)

ITEM

TAPPET

Stem outside dia.

Guide inside dia.

8

0

Tappet guide clearance

VALVE

SPRING

FREE

LENGTH

~~ ~ ~~~

I

ITEM

VALVE SEAT ANGLE(IN. EX.)

0

Valve cutter angle(a)

0

Valve contact width(b)

a

EH25-2

STD

Limit

7.960

-

7.975

(0.31 34

-

0.31

40)

8.000

-

8.01

5

(0.31

50

-

0.31

56)

0.025

-

0.055

(0.001

0

-

0.0022)

35.5

(1.4)

1

~

Unit: rnm

(in

EH12-2

11

7-2 125-2

STD

limit

a:

90"

b

:

0.7

-

1

.O

(0.028

-

0.039)

2.0

(0.079)

-

69

-

12-2 TORQUE SPECIFICATIONS

EH12-2

/

17-2

type

TIGHTENING TORQUE

N*m

ft-

Ib

kg cm

DESCRIPTION

Cylinder head bolts

5.7

-

7.2 80

-

100

7.8

-

9.8

Main bearing cover bolts

43

-

47

600

-

650

58.8

-

63.7

Flywheel nut

Connecting rod cap

bolts

16.6

-

19.5

230

-

270 22.5

-

26.5

EH12-2

12.2-14.4

6.5-8.3 170-200 90-115

.16.6-19.6 8.8-11.2 EH17-2

EH12-2

EH17-2 EH12-2 EH17-2

New spark plug

16.6

-

19.5

230

-

270

22.6

-

26.5

Retightening

8.7

-

10.9

120

-

150

11.8-14.7

Spark plug

EH25-2

type

TIGHTENING TORQUE

Nom

ft-lb

kg

cm

DESCRIPTION

Cylinder head

bolts

43

-

47

600

-

650

58.8

-

63.7

Flywheel nut

16.3

-

19.8

225

-

275 21.3

-

26.9 Connecting

rod

cap bolts

24.6

-

30.3

340

-

420 33.3

-

41.2

Main bearing cover

bolts

1

16.7-18.6

I

170

-

190

I

12.3- 13.7

I

New spark

plug

I

11.8

-

14.7

I

120

-

150

I

8.7

-

10.9

I

Retightening

I

22.6

-

26.5

I

230

-

270

I

16.6

-

19.5

-

70

-

12-3

OIL

GRADE

CHART

Specified

Lubrican

Quality

T-

Single

grade

Multi-

grade

Comparison between oil viscosity and temparature

I

1

I I

I

-

20

-

10

0

10

20

30

40

"C

-4 14

32 50

68

86

104

"F

Use

oil classified

as

SE

or higher.

Multi-grade oil tends

to

increase its consumption at high ambient temperature.

-

71

-

13.

MAINTENANCE AND STORAGE

The following maintenance

jobs

apply when the engine

is

operated correctly under normal conditions.

The indicated maintenance intervals are

by

no means guarantees

for

maintenance free operations during

these intervals.

For example,

if

the engine

is

operated in extremely dusty conditions, the air cleaner should be cleaned

every day instead

of

every

50

hours.

13-1

DAILY MAINTENANCE

MAINTENANCE

1)

Clean away dust and chaff from engine.

2)

Check fuel leakage from fuel system. If any,

retighten fasteners

or

replace necessary

parts.

3)

Inspect for loose hardwares and retighten if

necessary.

4)

Check

oil

level and add

to

full

mark.

REMARKS

Governor linkage is especially sensitive to dust.

~~ ~ ~~ ~~

Loose

bolts

and

nuts

may come

off

and result

in

breakage of other

parts.

~~

13-2

INITIAL

20

HRS.

MAINTENANCE

MAINTENANCE REMARKS

L

I

1)

Change crankcase oil.

To

remove

sludge

from

run

-

in

operation.

I

13-3

EVERY

50

HRS.

(10

DAYS)

MAINTENANCE

MAINTENANCE REMARKS

I

1)

Change crankcase oil. Contaminated

oil

quickens

wear.

I

2)

Clean

air

cleaner.

3)

Check and clean spark plug. If dirty, wash in gasoline

or

polish with emery paper.

-

72

-

13-4

EVERY

100-200

HRS. (MONTHLY) MAINTENANCE

I

MAINTENANCE

I

REMARKS

I

~

1)

Clean fuel filter and fuel

tank.

2)

Inspect cooling system and remove

dirt

and

Remove blower housing and clean

up

between fins and housing.

chaff.

13-5

EVERY

500-600

HRS. MAINTENANCE

I

MAINTENANCE

I

REMARKS

I

1)

Remove carbon from cylinder head.

~ ~~~

I

Carbon deposits

in

combustion chamber causes lack

of

power.

I

2)

Disassemble and clean carburetor.

I

13-6

EVERY

1000

HRS. (YEARLY) MAINTENANCE

MAINTENANCE REMARKS

1)

Overhaul engine. Clean and correct parts.

Replace piston rings and other necessary parts.

2)

Replace fuel lines once a

year.

Avoid hazards caused

by

fuel leakage.

13-7

ENGINE STORAGE

(1)

Perform the above

13-1

and

13-2

maintenance

jobs.

(2)

Drain fuel from the fuel tank and carburetor float chamber.

(3)

To

prevent rust in the cylinder bore,

apply

oil

through the sp

several turns by hand. Reinstall the plug. ark plug hole and turn the crankshaft

(4)

Turn the starting pulley

by

hand

and

leave it where the

resistance

is

the heaviest.

(5)

Clean outside

of

the engine with

oiled

cloth.

(6)

Put

a

plastic cover

or

the like over the engine and store the engine in dry place.

-

73

-

SU6ARU

~bin America, Inc.

940 Lively Blvd.

l

Wood Dale, IL 60191

l

Phone: 630-350~8200

l

Fax: 630-350-8212

e-mail: sale.s@robinamerica.com

l

www.robinamerica.com

PRINTED IN THE USA I

Subaru Robin Power Products Eh12 2 Eh17 Eh25 Users Manual ES1154

EH12-2, EH17-2, EH25-2 to the manual 595a0410-5dc6-bf04-6953-1165256855f8

Navigation menu

Versions of this User Manual:

Views

Navigation