Kymco MXER 125 150 Service Manual

PREFACE

This Service Manual describes the

technical features and servicing

procedures for the KYMCO MX’er

125/150.

Section 1 contains the precautions for

all operations stated in this manual.

Read them carefully before starting any

operation.

Section 2 is the removal/installation

procedures for the frame covers which

are subject to higher removal/installation

frequency during maintenance and

servicing operations.

Section 3 describes the inspection/

adjustment procedures, safety rules and

service information for each part,

starting from periodic maintenance.

Sections 4 through 17 give instructions

for disassembly, assembly and

inspection of engine, chassis frame and

electrical equipment.

Most sections start with an assembly or

system illustration and troubleshooting

for the section. The subsequent pages

give detailed procedures for the section.

KWANG YANG MOTOR CO., LTD.

OVERSEAS SALES DEPARTMENT

OVERSEAS SERVICE SECTION

TABLE OF CONTENTS

GENERAL INFORMATION 1

FRAME COVERS/EXHAUST MUFFLER 2

INSPECTION/ADJUSTMENT 3

LUBRICATION SYSTEM 4

FUEL SYSTEM 5

ENGINE REMOVAL/INSTALLATION 6

CYLINDER HEAD/VALVES 7

CYLINDER/PISTON 8

DRIVE AND DRIVEN PULLEYS 9

FINAL REDUCTION/TRANSMISSION

SYSTEM 10

CRANKCASE/CRANKSHAFT/

BALANCE SHAFT 11

FRONT WHEEL/FRONT BRAKE/

FRONT SUSPENSION/STEERING

SYSTEM 12

REAR WHEEL /SWING

ARM/HYDRAULIC BRAKE 13

BATTERY/CHARGING SYSTEM/A.C.

GENERATOR 14

IGNITION SYSTEM 15

STARTING SYSTEM 16

LIGHTS/SWITCHES 17

ONLY ATV ON ROAD AVAILABLE 18

ENGINE CHASSIS

ELECTRICAL

EQUIPMENT

The information and contents included

in this manual may be different from

the motorcycle in case specifications

are changed.

1. GENERAL INFORMATION

1-0

MX’er SYSTEM

1

__________________________________________________________________________________

1

____________________________________________________________________

GENERAL INFORMATION

____________________________________________________________________

SERIAL NUMBER---------------------------------------------------------- 1- 1

SPECIFICATIONS ---------------------------------------------------------- 1- 2

SERVICE PRECAUTIONS------------------------------------------------ 1- 4

TORQUE VALUES --------------------------------------------------------- 1-12

SPECIAL TOOLS ----------------------------------------------------------- 1-14

LUBRICATION POINTS -------------------------------------------------- 1-15

CABLE & HARNESS ROUTING ---------------------------------------- 1-18

WIRING DIAGRAM-------------------------------------------------------- 1-22

TROUBLESHOOTING----------------------------------------------------- 1-23

1. GENERAL INFORMATION

1-1

MX’er SYSTEM

SERIAL NUMBER

Location of Frame Serial Numbe

r

Location of Engine Serial Numbe

r

1. GENERAL INFORMATION

1-2

MX’er SYSTEM

SPECIFICATIONS

Name & Model No. LA30AA, AB

Motorcycle Name & Type MX’er

Overall length (mm) 1600

Overall width (mm) 980

Overall height (mm) 990

Wheel base (mm) 1120

Engine type O.H.C.

Displacement (cc) 149.4

Fuel Used 92# nonleaded gasoline

Front wheel 74

Net weight (kg) Rear wheel 78

Total 152

Front wheel 80

Gross weight(kg) Rear wheel 82

Total 162

Front wheel 20*7-8

Rear wheel 22*10-8

Ground clearance (mm) 130

Perform- Breaking distance

(m)(ANSI) 20.6 below

ance Min. turning radius (m) 3

Starting system Starting motor

Type Gasoline, 4-stroke

Cylinder arrangement Single cylinder

Combustion chamber type Semi-sphere

Valve arrangement O.H.C., chain drive

Bore x stroke (mm) 62 x 49.5

Compression ratio 9.7:1

Compression pressure

(kg/cm²) 16.0

Max. output (ps/rpm) 11/7500

Max. torque (kg m/rpm) 1.1/5500

Intake

Open 5.5° BTDC

Port (1mm) Close 27.5° ABDC

timing Exhaust Open 36° BBDC

(1mm)

Close 4° ATDC

Valve clearance Intake 0.06

(cold) (mm) Exhaust 0.06

Idle speed (rpm) 1700rpm

Lubrication type Forced pressure &

wet sump

Oil pump type Inner/outer rotor type

Oil filter type Full-flow filtration

Oil capacity 1.0 liter

Oil exchanging

capacity 0.9 liter

Cooling Type Forced air cooling

Air cleaner type & No Sponge

Fuel capacity 8.1 liters

Type PD

Float lever 14.8mm

Venturi dia.(mm) φ25

Throttle type PISTON

Type CDI

Ignition timing 15°BTDC/1700rpm

Contact breaker Non-contact point type

Spark plug

NGK

CR8E

Spark plug gap 0.60.7mm

Battery Capacity 12V8AH

Clutch Type CVT

Type Helical gear

Operation Automatic centrifugal

type

Type Chain drive

Reduction 1st 2.8-0.95

ratio 2nd 7.226

Counter gear ratio 26.902

Front Caster angle

Axle Trail length

Tire

p

ressure Fron

t

0.2

(kg/cm²) Rear 0.25

Turning Left 44°

angle Right 44°

Brake s

y

ste

m

Rea

r

Disk brake Drum brake

type Front Drum brake

Sus

p

ension Fron

t

Swin

g

type Rear Swing arm

Shock Front Swing

type Rear Swing arm

Frame type SP pipe

Fuel S

y

stem

Carbureto

r

Electrical Equipment

I

g

nition S

y

stem

Tires

Power Drive System

Transmis-

sion Gear Reduction

Gear

Moving Device

Engine

Damping

Device

Lubrication

S

y

stem

1. GENERAL INFORMATION

1-3

MX’er SYSTEM

SPECIFICATIONS

Name & Model No. LA25AB

Motorcycle Name & Type MX’er

Overall length (mm) 1685

Overall width (mm) 980

Overall height (mm) 990

Wheel base (mm) 1120

Engine type OHC

Displacement (cc) 124

Fuel Used 92# nonleaded gasoline

Front wheel 74

Net weight (kg) Rear wheel 78

Total 152

Front wheel 80

Gross weight(kg) Rear wheel 82

Total 162

Front wheel 20*7-8

Rear wheel 22*10-8

Ground clearance (mm) 130

Perform- Breaking distance

(m)(ANSI) 20.6 below

ance Min. turning radius (m) 2.5

Starting system Starting motor

Type Gasoline, 4-stroke

Cylinder arrangement Single cylinder

Combustion chamber type Semi-sphere

Valve arrangement O.H..C., chain drive

Bore x stroke (mm) 56.5 x 49.5

Compression ratio 9.2:1

Compression pressure

(kg/cm²) 14.0

Max. output (ps/rpm) 9.8/7500

Max. torque (kg m/rpm) 0.98/5500

Intake

Open 5.5° BTDC

Port (1mm) Close 27.5° ABDC

Timi

n

g

Exhaust Open 36° BBDC

(1mm)

Close 4° ATDC

Valve clearance Intake 0.06

(cold) (mm) Exhaust 0.06

Idle speed (rpm) 1700rpm

Lubrication type Forced pressure &

wet sump

Oil pump type Inner/outer rotor type

Oil filter type Full-flow filtration

Oil capacity 1.0 liter

Oil exchanging

capacity 0.9 liter

Cooling Type Forced air cooling

Air cleaner type & No Sponge

Fuel capacity 8.1 liters

Type PD

Piston dia. (mm) 14.8mm

Venturi dia.(mm) φ25

Throttle type PISTON

Type CDI

Ignition timing 15°BTDC/1700rpm

Contact breaker Non-contact point type

Spark plug NGK

CR8E

Spark plug gap 0.60.7mm

Battery Capacity 12V8AH

Clutch Type CVT

Type Helical gear

Operation Automatic centrifugal

type

Type Chain drive

Reduction 1st 2.8-0.95

ratio 2nd 7.226

Counter gear ratio 26.902

Front Caster angle

Axle Trail length

Tire

p

ressure Fron

t

0.2

(kg/cm²) Rear 0.25

Turning Left 44°

angle Right 44°

Brake s

y

ste

m

Rea

r

Disk brake Drum brake

type Front Drum brake

Sus

p

ension Fron

t

Swin

g

type Rear Swing arm

Shock Front Swing

type Rear Swing arm

Frame type SP pipe

Fuel S

y

stem

Carbureto

r

I

g

nition S

y

stem

Electrical Equipment

Tires

Power Drive System

Transmis-

sion Gear Reduction

Gear

Moving Device

Engine

Damping

Device

Lubrication

S

y

stem

1. GENERAL INFORMATION

1-4

MX’er SYSTEM

SERVICE PRECAUTIONS

 Make sure to install new gaskets, O-rings,

circlips, cotter pins, etc. when

reassembling.

 When tightening bolts or nuts, begin with

larger-diameter to smaller ones at several

times, and tighten to the specified torque

diagonally.

 Use genuine parts and lubricants.

 When servicing the motorcycle, be sure

to use special tools for removal and

installation.

 After disassembly, clean removed parts.

Lubricate sliding surfaces with engine oil

before reassembly.

1. GENERAL INFORMATION

1-5

MX’er SYSTEM

 Apply or add designated greases and

lubricants to the specified lubrication

points.

 After reassembly, check all parts for

proper tightening and operation.

 When two persons work together, pay

attention to the mutual working safety.

 Disconnect the battery negative (-)

terminal before operation.

 When using a spanner or other tools,

make sure not to damage the motorcycle

surface.

 After operation, check all connecting

points, fasteners, and lines for proper

connection and installation.

 When connecting the battery, the positive

(+) terminal must be connected first.

 After connection, apply grease to the

battery terminals.

 Terminal caps shall be installed securely.

1. GENERAL INFORMATION

1-6

MX’er SYSTEM

 If the fuse is burned out, find the cause

and repair it. Replace it with a new one

according to the specified capacity.

 After operation, terminal caps shall be

installed securely.

 When taking out the connector, the lock

on the connector shall be released before

operation.

 Hold the connector body when

connecting or disconnecting it.

 Do not pull the connector wire.

 Check if any connector terminal is

bending, protruding or loose.

Confirm

Capacity

1. GENERAL INFORMATION

1-7

MX’er SYSTEM

 The connector shall be inserted

completely.

 If the double connector has a lock,

lock it at the correct position.

 Check if there is any loose wire.

 Before connecting a terminal, check

for damaged terminal cover or loose

negative terminal.

 Check the double connector cover for

proper coverage and installation.

 Insert the terminal completely.

 Check the terminal cover for proper

coverage.

 Do not make the terminal cover opening

face up.

 Secure wire harnesses to the frame with

their respective wire bands at the

designated locations.

Tighten the bands so that only the

insulated surfaces contact the wire

harnesses.

Sna

pp

in

g

!

1. GENERAL INFORMATION

1-8

MX’er SYSTEM

 After clamping, check each wire to make

sure it is secure.

 Do not squeeze wires against the weld or

its clamp.

 After clamping, check each harness to

make sure that it is not interfering with

any moving or sliding parts.

 When fixing the wire harnesses, do not

make it contact the parts which will

generate high heat.

 Route wire harnesses to avoid sharp

edges or corners. Avoid the projected

ends of bolts and screws.

 Route wire harnesses passing through the

side of bolts and screws. Avoid the

projected ends of bolts and screws.

No Contact !

1. GENERAL INFORMATION

1-9

MX’er SYSTEM

 Route harnesses so they are neither

pulled tight nor have excessive slack.

 Protect wires and harnesses with

electrical tape or tube if they contact a

sharp edge or corner.

 When rubber protecting cover is used to

protect the wire harnesses, it shall be

installed securely.

 Do not break the sheath of wire.

 If a wire or harness is with a broken

sheath, repair by wrapping it with

protective tape or replace it.

 When installing other parts, do not press

or squeeze the wires.

Do not pull

too ti

g

ht!

Do not press

or squeeze

the wire.

1. GENERAL INFORMATION

1-10

MX’er SYSTEM

 After routing, check that the wire

harnesses are not twisted or kinked.

 Wire harnesses routed along with

handlebar should not be pulled tight, have

excessive slack or interfere with adjacent

or surrounding parts in all steering

positions.

 When a testing device is used, make sure

to understand the operating methods

thoroughly and operate according to the

operating instructions.

 Be careful not to drop any parts.

 When rust is found on a terminal, remove

the rust with sand paper or equivalent

before connecting.

Do you understand

the instrument?

Is the instrument set

correctly?

Remove Rust !

1. GENERAL INFORMATION

1-11

MX’er SYSTEM

 Symbols:

The following symbols represent the

servicing methods and cautions included

in this service manual.

: Apply engine oil to the

specified points. (Use

designated engine oil for

lubrication.)

: Apply grease for

lubrication.

: Transmission Gear Oil

(90#)

: Use special tool.

: Caution

: Warning

En

g

ine Oil

Grease

Gear Oil

Special

1. GENERAL INFORMATION

1-12

MX’er SYSTEM

TORQUE VALUES

STANDARD TORQUE VALUES

Ite

m

Torque (k

g

f-m) Ite

m

Torque (k

g

f-m)

5mm bolt, nut

6mm bolt, nut

8mm bolt, nut

10mm bolt, nut

12mm bolt, nut

14mm bolt, nut

0.450.6

0.81.2

1.82.5

3.04.0

5.06.0

6.08.0

4mm screw

5mm screw

6mm screw, SH bolt

6mm flange bolt and nut

8mm flange bolt and nut

10mm flange bolt and nut

0.150.4

0.30.5

0.71.1

1.01.4

2.43.0

3.54.5

Torque specifications listed below are for important fasteners.

ENGINE

Item Q‘ty Thread dia.(mm) Torque (kgf-m) Remarks

Stud bolt

Oil filter screen cap

Seat ball stopper bolt

Bearing hold

L cover

Stud bolt

Cam holder

Tappet ADJ nut

Pivot tensioner

Lifter tensioner

MISTON oil drive bolt

Driver face

Clutch outer

Oneway clutch

Balancer shaft

ACG flywheel

Spark plug

Drain bolt mission

Drain plug

Clamper wre harness

Motor srart

Oil pump

Oil pump sprocket

Head CYL bolt

Drive plate nut

Startor

4

1

8

4

2

1

2

1

9

1

3

1

2

1

4

8

30

14

6

8

6

8

6

12

8

16

14

8

12

6

22

5

0.71.1

1.02.0

4.55.0

1.01.2

1.01.4

0.71.1

1.82.2

1.41.8

0.81.2

1.01.4

0.350.5

0.81.2

5.56.5

5.06.0

2.43.0

4.05.0

5.06.0

1.12.3

0.81.2

2.03.0

0.81.2

5.06.0

0.81.2

1. GENERAL INFORMATION

1-13

MX’er SYSTEM

Item Q‘ty Thread dia.(mm) Torque (kgf-m) Remarks

R cover

Head cover

Cap R cover

Guide star change handle

Sprocket drive plate

Carburetor

Check bolt oil

9

4

1

3

2

1

6

10

0.81.2

1.01.6

0.81.2

1.01.5

FRAME

Item Q‘ty Thread dia.(mm) Torque (kgf-m) Remarks

Steering stem nut

Swing arm nut

Rear wheel nut

Front wheel nut

Rear shock absorber upper mount bolt

Front shock absorber upper mount bolt

Front shock absorber lower mount bolt

Rear fork axle

Rear hub nut

Rear wheel shaft nut

Rear engine bracket up bolt

Rear engine bracket bolt

Engine hanger bracket bolt

Exhaust muffler lock bolt

1

4

2

1

2

1

4

2

1

2

14

10

14

10

14

12

32

10

8

6.08.0

4.05.0

6.08.0

3.54.5

6.08.0

11.013.0

3.54.5

3.23.8

1. GENERAL INFORMATION

1-14

MX’er SYSTEM

SPECIAL TOOLS

Tool Name Tool No. Remarks Ref. Page

Flywheel puller E003

Lock nut wrench E009

Valve adjuster E012

Valve spring compressor E040

Oil seal and bearing install E014

Universal holder E017

Flywheel holder E021

Clutch spring compressor E027

Bearing puller E008

Bearing puller E018

Bearing puller E020

Bearing puller E031

Nut wrench F010

Float level gauge

1. GENERAL INFORMATION

1-15

MX’er SYSTEM

LUBRICATION POINTS

ENGINE

Lubrication Points Lubricant

Valve guide/valve stem movable part

Cam lobes

Valve rocker arm friction surface

Cam chain

Cylinder lock bolt and nut

Piston surroundings and piston ring grooves

Piston pin surroundings

Cylinder inside wall

Connecting rod/piston pin hole

Connecting rod big end

Crankshaft right side oil seal

Crankshaft one-way clutch movable part

Oil pump drive chain

Balance gear

A.C. generator

Starter one-way clutch

Bearing movable part

O-ring face

Oil seal lip

•Genuine KYMCO Engine Oil (SAE15W-40)

•API SG Engine Oil

Transmission gear and movable parts Gear oil: SAE90#

1. GENERAL INFORMATION

1-16

MX’er SYSTEM

FRAME

The following is the lubrication points for the frame.

Use general purpose grease for parts not listed.

Apply clean engine oil or grease to cables and movable parts not specified. This will avoid

abnormal noise and rise the durability of the motorcycle.

Steering knuckle/Thrust

Cover/Bush/Colla

r

Steering Column Uppe

r

Front Brake

camshaft/Oil

Seal/O-ring

Steering knuckle/Thrust

Cover/Bush/Colla

r

Front Arm Bush

Front Brake

camshaft/Oil

Seal/O-ring

Steering Column Lowe

r

Front Wheel

Oil Seal

Front Arm Bush

Rear Brake Cable

Throttle Cable

Front Brake Cable

Front Wheel

Oil Seal

1. GENERAL INFORMATION

1-17

MX’er SYSTEM

Swing arm Thrust

Cove

r

Rear Brake Cam/

Axle Hub Collar/Oil

Seal/Bearing

Sprocket hub/Rear

Axle Hub Collar/Oil

Seal/Bearing

Driven Sprocket

1. GENERAL INFORMATION

1-18

MX’er SYSTEM

CABLE & HARNESS ROUTING

Rear Brake Cable

Throttle Cable

Front Brake Cable

Handlebar Switch Lea

d

Right Front Brake Cable

Left Front Brake Cable

1. GENERAL INFORMATION

1-19

MX’er SYSTEM

Breather Hose (CYL

Head Cover)

Main Switch

Inlet Hose

Breather

Hose

(C k )

1. GENERAL INFORMATION

1-20

MX’er SYSTEM

Wire Harness

Breather Hose

Rectifier/Regulato

Ignition Coil

Outlet Hose

Fuse

1. GENERAL INFORMATION

1-21

MX’er SYSTEM

Battery Negative

Cable

Battery

A.C.G Wire

Connector

Breather Hose (CYL

Head Cover)

Positive Cable

CDI Unit

Chan

g

e Gear Control

Starter Relay

Fuse

1. GENERAL INFORMATION

1-22

MX’er SYSTEM

WIRING DIAGRAM

1. GENERAL INFORMATION

1-23

MX’er SYSTEM

TROUBLESHOOTING

ENGINE WILL NOT START OR IS HARD TO START

Empty fuel tank

Clogged fuel line between fuel

tank and carburetor

Clogged float oil passage

Clogged fuel tank cap breather

hole

Clogged fuel filter

Clogged fuel valve passage

Faulty spark plug

Fouled spark plug

Faulty CDI unit

Faulty change gear control unit

Faulty pulser coil

Broken or shorted ignition coil

Broken or shorted exciter coil

Faulty ignition switch

Weak or dead battery

Faulty starter clutch

Valve clearance too small

Valve stuck open

Worn cylinder, piston and piston

rings

Leaking cylinder head gasket

Air leaking through intake pipe

Leaking intake manifold

Incorrect ignition timing

Incorrectly adjusted air*/ screw

Flooded carburetor

Clogged air cleaner

Throttle valve excessively open

Check if fuel reaches

carburetor by loosening

drain screw

Remove spark plug and

install it into spark plug

cap to test spark by

connecting it to engine

ground

Inspection/Adjustment

Spark jumps

Normal

compression

Engine does not

fire

Weak or no spark

Low or no

compression

Engine fires but

does not start

Test cylinder

compression

Start engine by

follow-ing normal

startin

g

p

rocedure

Fuel reaches

carburetor Fuel does not

reach carburetor

Wet spark plug

Dry spark plug

Symptom

Remove spark plug and

inspect again

Probable Cause

1. GENERAL INFORMATION

1-24

MX’er SYSTEM

ENGINE LACKS POWER

Clogged air cleaner

Restricted fuel flow

Clogged fuel tank cap breather hole

Clogged exhaust muffler

Carburetor fuel level too low

Faulty CDI unit

Faulty pulser coil

Improper valve clearance

adjustment

Excessively worn valve seat

(protruded valve stem)

Improper valve and seat contact

Worn cylinder and piston rings

Leaking cylinder head gasket

Improper valve timing

Clean and unclog

Fouled spark plug

Incorrect heat range plug

Oil level too high

Oil level too low

Oil not changed

Clogged oil line

Faulty oil pump

Worn cylinder and piston rings

Mixture too lean

Poor quality fuel

Excessive carbon build-up in

combustion chamber

Ignition timing too early

Excessive carbon build-up in

combustion chamber

Poor quality fuel

Clutch slipping

Mixture too lean

Ignition timing too early

Start engine and

accelerate lightly for

observation

Inspection/Adjustment Symptom

Engine speed

increases

Correct timin

g

Engine speed does not

increase sufficientl

y

Incorrect timin

g

Check ignition timing

(using a timing light)

Test cylinder compression

Check carburetor for

clogging

Rapidly accelerate or run

at hi

g

h s

p

eed

Remove spark plug and

ins

p

ec

t

Check if engine overheats

Check valve clearance

Correc

t

Incorrec

t

N

ormal

com

p

ression Abnormal

compression

Remove oil dipstick and

check oil level and condition

Engine overheats

Engine does no

t

overheats

Plug not fouled o

r

discolored Plug fouled or

discolored

Correct and no

t

contaminated Incorrect o

r

contaminated

Valve train lubricated

p

ro

p

erl

y

Valve train not

lubricated

p

ro

p

erl

y

Engine does not knock Engine knocks

Not clo

gg

ed Clo

gg

ed

Remove cylinder head oil

p

i

p

e bolt and ins

p

ec

t

Probable Cause

1. GENERAL INFORMATION

1-25

MX’er SYSTEM

POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)

Faulty CDI unit

Faulty pulser coil

Mixture too rich (turn screw

out)

Mixture too lean (turn screw in)

Deteriorated O-ring

Carburetor not securely

tightened

Damaged insulator rubber

Faulty or fouled spark plug

Faulty CDI unit

Faulty A.C. generator

Faulty ignition coil

Broken or shorted spark plug

wire

Faulty ignition switch

Remove spark plug and

install it into spark plug

cap to test spark by

connecting it to engine

g

round

Symptom

Correctly adjusted

No air leak Air leaks

Good spark Weak or inte

r

-

mittent spark

Incorrectly adjusted

Incorrect timing

Correct timing

Probable Cause Inspection/Adjustment

Check ignition timing

Check carburetor ai

r

screw adjustment

Check carburetor gasket

for air leaks

1. GENERAL INFORMATION

1-26

MX’er SYSTEM

POOR PERFORMANCE (AT HIGH SPEED)

Faulty CDI unit

Faulty pulser coil

Improperly adjusted valve

clearance

Worn valve seat

Empty fuel tank

Clogged fuel tube or filter

Clogged Fuel tank cap breather

hole

Clean and unclog

Cam timing gear aligning marks

not aligned

Faulty spring

Inspection/Adjustment Symptom

Check carburetor jets

for clogging

Check fuel pump fo

r

fuel supply

Correct ti

m

ing Incorrect timing

Fuel flows freely Fuel flow restricted

Correc

t

Incorrec

t

Not clogged Clogged

Not weakened Weak spring

Incorrectly adjusted

Correctly adjusted

Check valve clearance

Check valve spring

tension

Probable Cause

Check ignition timing

Check valve timing

1. GENERAL INFORMATION

1-27

MX’er SYSTEM

POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING)

Undercharging

Inspection/Adjustment Symptom Probable Cause

Dead battery

Faulty battery

Faulty A.C. generator coil

Broken yellow wire

Shorted pink and yellow

wires

Broken red wire

Faulty regulator/rectifier

Poorly connected coupler

Faulty A.C. generator

Overcharging

Broken green wire

Poorly connected coupler

Faulty regulator/rectifier

Start engine and test

limit voltage of battery

terminals

Connect battery (+) wire

to regulator/rectifier

coupler red wire and

battery (-) wire to engine

g

round and test volta

g

e

Inspection/Adjustment Symptom

Normal voltage

B

attery

h

as vo

l

tage

with ignition

switch “ON”

Normal

Voltage does no

t

increase

Normal Abnormal

B

attery

h

as no

voltage with ignition

switc

h

“ON”

Resistance too high

Normal voltage No voltage

Normal Abnormal

Measure resistance

between AC generator

coil terminals

Probable Cause

Check regulator/rectifier

coupler for loose

connection

Connect battery (+) wire

to regulator/rectifier

coupler green wire and

battery (-) wire to engine

g

round and test volta

g

e

Check regulator/rectifier

coupler for loose

connection

1. GENERAL INFORMATION

1-28

MX’er SYSTEM

NO SPARK AT SPARK PLUG

Inspection/Adjustment Symptom Probable Cause

Faulty spark plug

Loose spark plug cap

Poorly connected coupler

Faulty ignition switch

Weak battery

Faulty pulser coil

Faulty ignition coil

Faulty charging system

Broken wire harness

Poorly connected coupler

Faulty CDI unit

Faulty change gear control

unit

Faulty ignition coil

Replace with a new

spark plug and inspect

a

g

ain

Check CDI unit coupler

for looseness

Normal

Abnormal

Normal

Abnormal

Normal Abnormal

Abnormal

Measure resistance

between terminals of

CDI unit cou

p

le

r

Check related parts

Check ignition coil with

a CDI unit tester

Weak or no spark

Not loose

Good spark

Good Good

Check CDI unit with a

CDI unit tester

Loose

Check spark plug cap

and high-tension wire

for looseness

2. FRAME COVERS/EXHAUST MUFFLER

2-0

MX’er SYSTEM

2

__________________________________________________________________________________

____________________________________________________________________

2

____________________________________________________________________

FRAME COVERS/EXHAUST MUFFLER

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 2- 2

TROUBLESHOOTING----------------------------------------------------- 2- 2

FRAME COVERS----------------------------------------------------------- 2- 3

HEADLIGHT REMOVAL ------------------------------------------------- 2- 5

EXHAUST MUFFLER REMOVAL-------------------------------------- 2- 5

2. FRAME COVERS/EXHAUST MUFFLER

2-1

MX’er SYSTEM

2. FRAME COVERS/EXHAUST MUFFLER

2-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• When removing frame covers, use special care not to pull them by force because the cover joint

claws may be damaged.

• Make sure to route cables and harnesses according to the Cable & Harness Routing.

TORQUE VALUES

Exhaust muffler lock bolt 3.23.8kgf-m

Exhaust muffler joint lock nut 0.81.2kgf-m

TROUBLESHOOTING

Noisy exhaust muffler

• Damaged exhaust muffler

• Exhaust muffler joint air leaks

Lack of power

• Caved exhaust muffler

• Exhaust muffler air leaks

• Clogged exhaust muffler

2. FRAME COVERS/EXHAUST MUFFLER

2-3

MX’er SYSTEM

FRAME COVERS

SEAT REMOVAL

Pull the lever backward, then pull up the

seat at the rear.

Remove the seat.

LEFT REAR FENDER REMOVAL

Remove seven screws and two bolts

attaching the left rear fender.

Remove the left rear fender under bolt.

Remove the left rear fender.

RIGHT REAR FENDER REMOVAL

Remove seven screws and two bolts

attaching the right rear fender.

Sea

t

Screws

Frame Lef

t

Cove

r

Bol

t

Bol

t



During rem

Bol

t

Frame Ri

g

h

t

Cove

r

During removal, do not pull the joint

claws forcedly to avoid damage.



oval, do not pull the joint

aclaws forcedly to avoid dam ge.

2. FRAME COVERS/EXHAUST MUFFLER

2-4

MX’er SYSTEM

Remove right rear fender under bolt.

Remove the right rear fender.

FLOOR BOARD COVER REMOVAL

Remove the four bolts on the floorboard

cover.

Remove the floorboard cover.

FRONT COVERS REMOVAL

Remove the two screws on the front cover.

Remove the left and right front fender under

bolt.

Remove the front cover.

FRONT FENDER REMOVAL

Remove the left and right front fender under

bolt.

Remove screws attaching the left and right

front fender.

Remove the left and right front fender.

Bol

t

Floor Board Cove

r

Bolts

Bol

t

Screws

Front Cove

r

During removal, be careful not to

damage the joint claws.



2. FRAME COVERS/EXHAUST MUFFLER

2-5

MX’er SYSTEM

HEADLIGHT REMOVAL

Remove the headlight connector wire.

Remove the two bolts on the headlight.

EXHAUST MUFFLER

REMOVAL

Remove the two bolts attaching the exhaust

muffler.

Remove the two exhaust muffler joint lock

nuts.

Remove the exhaust muffler joint packing

collar.

When installing, first install the exhaust

muffler packing collar onto the engine and

then install the exhaust muffler.

Torque:

Exhaust muffler lock bolt: 3.23.8kgf-m

Exhaust muffler joint lock nut: 0.8

1.2kgf-m

Bol

t

s

Joint Lock Nuts

Bol

t

s

Be sure to install a new exhaust muffler

packing collar.



3. INSPECTION/ADJUSTMENT

3-0

MX’er SYSTEM

3

__________________________________________________________________________________

____________________________________________________________________

3

____________________________________________________________________

INSPECTION/ADJUSTMENT

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 3- 1

MAINTENANCE SCHEDULE-------------------------------------------- 3- 2

FUEL LINE/THROTTLE OPERATION/AIR CLEANER ------------ 3- 3

AIR FILTER FOR DRIVE BELT ----------------------------------------- 3- 4

SPARK PLUG---------------------------------------------------------------- 3- 5

VALVE CLEARANCE/CARBURETOR IDLE SPEED--------------- 3- 6

IGNITION TIMING/CYLINDER COMPRESSION ------------------- 3- 7

ENGINE OIL/FINAL REDUCTION GEAR OIL----------------------- 3- 8

DRIVE BELT/BRAKE SHOE/BRAKE SYSTEM --------------------- 3- 9

HEADLIGHT AIM---------------------------------------------------------- 3-11

STEERING SYSTEM INSPECTION------------------------------------- 3-11

TOE-IN ADJUSTMENT --------------------------------------------------- 3-12

WHEELS/TIRES ------------------------------------------------------------ 3-13

DRIVE CHAIN SLACK ADJUSTMENT-------------------------------- 3-14

CABLE INSPECTION AND LUBRICATION-------------------------- 3-16

FRONT SUSPENSION LUBRICATION -------------------------------- 3-16

3. INSPECTION/ADJUSTMENT

3-1

MX’er SYSTEM

SERVICE INFORMATION

GENERAL

 WARNING

•Before running the engine, make sure that the working area is well-ventilated. Never run the

engine in a closed area. The exhaust contains poisonous carbon monoxide gas which may

cause death to people.

•Gasoline is extremely flammable and is explosive under some conditions. The working area

must be well-ventilated and do not smoke or allow flames or sparks near the working area or

fuel storage area.

SPECIFICATIONS

ENGINE

Throttle grip free play : 14mm

Spark plug gap : 0.60.7mm

Spark plug: Standard : NGK: CR8E

Valve clearance : IN: 0.06mm

EX: 0.06mm

Idle speed : 1700±100rpm

Engine oil capacity:

At disassembly : 1.0 liter

At change : 0.9 liter

Gear oil capacity :

At disassembly : 400cc

At change : 200cc

Cylinder compression : 16kg/cm²

Ignition timing : BTDC 15°/1700rpm

CHASSIS

Front brake free play: 1020mm

Rear brake free play: 1020mm

TIRE PRESSURE

1 Rider

Front 0.20kgf/cm²

Rear 0.25kgf/cm²

TIRE SIZE:

Front : 20*7-8

Rear : 22*10-8

TORQUE VALUES

Front wheel nut 5.06.0kgf-m

Rear wheel nut 5.06.0kgf-m

3. INSPECTION/ADJUSTMENT

3-2

MX’er SYSTEM

MAINTENANCE SCHEDULE

This chapter includes all information necessary to perform recommended inspections and

adjustments. These preventive maintenance procedures, if followed, will ensure more reliable

vehicle operation and a longer service life. The need for costly overhaul work will be greatly

reduced. This information applies to vehicles already in service ad well as new vehicles that are

being prepared for sale. All service technicians should be familiar with this entire chapter.

Initial Every

Item

Remarks 1

month 3

month 6

month 1

year

Valves Check valve clearance. Adjust if

necessary. ○ ○ ○ ○

Spark plug Check condition. Clean or replace if

necessary. ○ ○ ○ ○ ○

Air clearance Clean. Replace if necessary. ○ ○ ○ ○

Carburetor Check idle speed/starter operation.

Adjust if necessary. ○ ○ ○ ○

Fuel line Check fuel hose for cracks or

damage. Replace if necessary. ○ ○ ○

Engine oil Replace (Warm engine before

draining). ○ ○ ○ ○

Engine oil filter screen Clean. Replace if necessary. ○ ○

Transmission oil Check oil leakage. Replace every

12 months. ○ ○

Brake system Check operation. Adjust if

necessary. ○ ○ ○ ○ ○

Drive belt Check operation/replace if damage

or excessive wear. ○ ○

Wheels Check balance/damage/runout.

Replace if necessary. ○ ○ ○ ○

Wheel bearings Check bearings assembly for

looseness/damage. Replace if

damaged.

○ ○ ○ ○

Steering system Check operation/replace if damage.

Check toe-in/adjust if necessary. ○ ○ ○ ○ ○

Knuckle shafts Lubricate every 6 months. ○ ○ ○

Fitting/Fasteners Check all chassis fittings and

fasteners. Correct if necessary. ○ ○ ○ ○ ○

• In the interest of safety, we recommend these items should be serviced only by an authorized

KYMCO motorcycle dealer.

FUEL LINE

Remove the met-in box.

3. INSPECTION/ADJUSTMENT

3-3

MX’er SYSTEM

Check the fuel tubes and replace any parts,

which show signs of deterioration, damage

or leakage.

THROTTLE OPERATION

Check the throttle to swing for smooth

movement.

Measure the throttle to swing free play.

Free Play: 14mm

Minor adjustment is made with the

adjusting nut at the throttle to swing above.

Slide the rubber cover out and adjust by

loosening the lock nut and turning the

adjusting nut.

AIR CLEANER

AIR CLEANER REPLACEMENT

Remove the rear side covers.

Remove four screws on the air cleaner case

cover and the cover.

Check the element and replace it if it is

excessively dirty or damaged.

Do not smoke or allow flames or sparks

in your working area.



Fuel Filte

r

Adjusting Nu

t

Lock Nu

t

Screws

CLEAN AIR FILTER ELEMENT

Fuel tube

Air Cleaner Case Cove

r

Wash the element gently, but throughly in

solvent.

3. INSPECTION/ADJUSTMENT

3-4

MX’er SYSTEM

Use parts cleaning solvent only. Never

use gasoline or low flash point solvents

which may lead to a fire or explosion.



Squeeze the excess solvent out of the

element and let dry.

Apply the engine oil.

Squeeze out the excess oil.

CHANGE INTERVAL

More frequent replacement is required when

riding in unusually dusty or rainy areas.

AIR FILTER FOR DRIVE BELT

Remove the front cover.

Remove the screw, air filter case and air

filter element.

Inspect the air filter element.

Replace if damage.

Do not twist or wring out the foam

element. This could damage the foam

material.



The element should be wet but not

dri

pp

in

g

.



Air Cleaner Elemen

t

Front cove

r

Air Filter Case

Clean air filter element steps:

Tap the element lightly to remove most of

Screw

3. INSPECTION/ADJUSTMENT

3-5

MX’er SYSTEM

the dust and dirt.

Blow out the remaining dirt with

compressed air.

Install the air filter element and air filter

case.

Install the front cover.

SPARK PLUG

Remove the spark plug.

Check the spark plug for wear and fouling

deposits.

Clean any fouling deposits with a spark

plug cleaner or a wire brush.

Gap, Wear, and Fouling Deposits

Specified Spark Plug: NGK: CR8E

Measure the spark plug gap.

Spark Plug Gap: 0.60.7mm

VALVE CLEARANCE

Inspect and adjust valve clearance while

the engine is cold (below 35).



Cracks, Damage

Washer Deformation

When installing, first screw in the spark

plug by hand and then tighten it with a



spark plug wrench.

3. INSPECTION/ADJUSTMENT

3-6

MX’er SYSTEM

Remove the cylinder head cover.

Turn the flywheel counterclockwise so that

the “T” mark on the flywheel aligns with

the index mark on the crankcase to bring the

round hole on the camshaft gear facing up

to the top dead center on the compression

stroke.

Inspect and adjust the valve clearance.

Valve Clearance: IN: 0.06mm

EX: 0.06mm

Loosen the lock nut and adjust by turning

the adjusting nut

Tappet adjuster E012

CARBURETOR IDLE SPEED

Warm up the engine before this operation.

Start the engine and connect a tachometer.

Turn the throttle stop screw to obtain the

specified idle speed.

Idle Speed: 1700±100rpm

When the engine misses or run erratic,

adjust the air screw.

Bolts

Punch Marks

Valve Wrench

IGNITION TIMING

• Check the valve clearance again after

the lock nut is tightened.



• The engine must be warm for accurate

idle speed inspection and adjustment.



The CDI unit is not adjustable. If the

ignition timing is incorrect, check the

ignition system.



Throttle Stop Screw

Cylinder Head Cove

r

Special

Throttle Stop Screw

3. INSPECTION/ADJUSTMENT

3-7

MX’er SYSTEM

Remove the timing hole cap.

Check the ignition timing with a timing

light.

When the engine is running at idle speed,

the ignition timing is correct if the “F” mark

on the flywheel aligns with the index mark

on the crankcase.

CYLINDER COMPRESSION

Warm up the engine before compression

test.

Remove the spark plug.

Insert a compression gauge.

Open the throttle valve fully and push the

starter button to test the compression.

Compression: 16kg/cm²

If the compression is low, check for the

following:

- Leaky valves

- Valve clearance too small

- Leaking cylinder head gasket

- Worn piston rings

- Worn piston/cylinder

If the compression is high, it indicates that

carbon deposits have accumulated on the

combustion chamber and the piston head.

Compression Gauge

Timing Ligh

t

Timing Hole Cap ENGINE OIL

OIL LEVEL



3. INSPECTION/ADJUSTMENT

3-8

MX’er SYSTEM

Remove the oil dipstick and check the oil

level with the oil dipstick.

If the level is near the lower level, fill to the

upper level with the specified engine oil.

OIL CHANGE

Remove the oil drain plug bolt located on

the bottom of the engine to drain the engine

oil thoroughly.

After the oil has been completely drained,

Install the oil drain plug bolt.

Torque: 2..03.0kgf-m

Recommended Oil: SAE30#

FINAL REDUCTION GEAR OIL

Recommended Oil: GEAR OIL SAE90#

GEAR OIL CHANGE

Remove the oil filler bolt.

Removes the oil drains bolt and drain the oil

Oil Fille

r

Bol

t

Place the motorcycle on level g

r

ound for

oil level check.



Oil Dipstick

Oil Filter Screen Cap

Lower Level

Upper Level

• Place the motorcycle upright on level

ground for engine oil level check.

• Run the engine for 23 minutes and

check the oil level after the engine is

stopped for 23 minutes.

The engine oil will drain more easily

while the engine is warm.



oil drain

p

lu

g

bol

t

3. INSPECTION/ADJUSTMENT

3-9

MX’er SYSTEM

thoroughly.

Install the oil drain bolt.

Torque: 0.81.2kgf-m

Fill with the recommended oil.

Oil Capacity: At disassembly : 400cc

At change : 200cc

Reinstall the oil filler bolt and check for oil

leaks.

Torque: 0.81.2kgf-m

DRIVE BELT

Remove the left crankcase cover.

Inspect the drive belt for cracks, scaling,

chipping or excessive wear.

Measure the V-belt width

Service limit: 17mm

Replace the drive belt if out of specification.

BRAKE SHOE

Replace the brake shoes if the arrow on the

wear indicator plate aligns with the punch

mark on the brake panel when the brake is

fully applied.

BRAKE SYSTEM

FRONT BRAKE

Measure the front brake lever free play.

Free Play: 1020mm

Adjust if out of specification.

Make sure that the sealing washer is in

good condition.



Oil Drain Bolt/ Sealing Washe

r

Drive Bel

t

Wear Indicato

r

Punch Mark

Adjust brake lever free play:

Loosen the lock nuts.

3. INSPECTION/ADJUSTMENT

3-10

MX’er SYSTEM

Turn the adjusters in or out until the

specified free play is obtained.

Turning adjusters in that the free play is

increased.

Turning adjusters out that the free play is

decreased.

The difference between both clearances

should be 2 mm or less when front brake is

applied.

Tighten the lock nuts.

REAR BRAKE

Measure the rear brake lever free play.

Free Play: 1020mm

If the free play do not fall within the limit,

adjust by turning the adjusting nut.

HEADLIGHT AIM

Turn the ignition switch ON and start the

Adjusting Nu

t

Make sure that the

b

rake does not drag

after adjusting.



Lock Nuts Ad

j

usters

3. INSPECTION/ADJUSTMENT

3-11

MX’er SYSTEM

engine.

Turn on the headlight switch.

Adjust the headlight aim by turning the

headlight aim adjusting screw.

STEERING SYSTEM

INSPECTION

Place the machine on a level place.

Check the steering column bushings and

bearings:

Move the handlebar up and down, and/or

back and forth.

Replace the steering column bushings and

or bearings if excessive play

Check the tie-rod ends

Turn the handlebar to the left and/or right

until it stops completely, then slightly move

the handlebar from left to right.

Replace the tie-rod ends if tie-rod end has

any vertical play.

Raise the front end of the machine so that

there is no weight on the front wheels.

Check ball joints and/or wheel bearings.

Move the wheels lately back and froth.

Replace the front arms and/or wheel

bearings if excessive free play.

Adjusting Screw

Tie-rod Ends

TOE-IN ADJUSTMENT

Place the machine on a level place.

Measure the toe-in

3. INSPECTION/ADJUSTMENT

3-12

MX’er SYSTEM

Adjust if out of specification.

Toe-in measurement steps:

Mark both front tire tread centers.

Raise the front end of the machine so that

there is no weight on the front tires.

Fix the handlebar straight ahead.

Measure the width A between the marks.

Rotate the front tires 180 degrees until the

marks come exactly opposite.

Measure the width B between the marks.

Calculate the toe-in using the formula given

below.

Toe-in = BA

Toe-in: 010mm

If the toe-in is incorrect, adjust the toe-in

Adjust the toe-in step:

Mark both tie-rods ends.

This reference point will be needed during

adjustment.

Loosen the lock nuts (tie-rod end) of both

tie-rods

The same number of turns should be given

to both tie-rods right and left until the

specified toe-in is obtained, so that the

lengths of the rods will be kept the same.

Torque: 2.53.5kgf-m

WHEELS/TIRES

Check the tires for cuts, imbedded nails or

other damages.

Check the tire pressure.

• Be sure that both tie-rod are turned the

same amount. If not, the machine will

drift tight or left even though the

handlebar is positioned straight which

may lead to mishandling and accident.

• After setting the toe-in to specification,

run the machine slowly for some

distance with hands placed lightly on

the handlebar and check that the

handlebar responds correctly. If not,

turn either the right or left tie-rod

within the toe-in specification.



B

Tie-rod

Tie-rod End Nuts

A

3. INSPECTION/ADJUSTMENT

3-13

MX’er SYSTEM

TIRE PRESSURE

1 Rider

Front 0.20kgf/cm²

Rear 0.25kgf/cm²

TIRE SIZE

Front : 20*7-8

Rear : 22*10-8

Check the front axle nut for looseness.

Check the rear axle nut for looseness.

If the axle nuts are loose, tighten them to the

specified torque.

Torque: Front : 6.08.0kgf-m

Rear : 6.08.0kgf-m

WHEEL INSPECTION

Inspect the tire surfaces.

Replace if wear or damage.

Tire wear limit: 3.0mm

Inspect the wheel.

Replace if damage or bends

Always balance the wheel when a tire or

wheel has been changed or replaced.

Front Axle Nu

t



Tire pressure should be checked when

tires are cold.

Rea

r

Axle Nu

t

It is dangerous to ride with a worn out

tire. When a tire wear is out of

specification, replace the tire

immediately.



•

Never attempt even small repairs to the

wheel.

• Ride conservatively after installing a

tire to allow it to seat itself properly on



the rim.

3. INSPECTION/ADJUSTMENT

3-14

MX’er SYSTEM

DRIVE CHAIN SLACK

ADJUSTMENT

Before checking and/or adjusting, rotate the

rear wheels several revolutions and check

slack at several points to find the tightest

point. Check and/or adjust the chain slack

with the rear wheels in this “tightest”

position.

Place the machine on a level place.

Check drive chain slack.

Adjust if out of specification.

Drive chain slack: Approximately 30mm

Adjust drive chain slack:

Elevate the rear wheels by placing a suitable

stand under the rear of frame.

Loosen four bolts attaching rear axle hub.

Too little of chain slack will overload the

engine and other vital parts; keep the

slack within the specified limits.



Wheels should be on the ground without

the rider on it.



Bolts

Support the machine securely so there is

no danger of it falling over.



Turn the adjuster in or out until the

specified slack is obtained.

3. INSPECTION/ADJUSTMENT

3-15

MX’er SYSTEM

Turn out: Slack is decreased.

Turn in: Slack is increased.

Tighten four bolts attaching rear axle hub to

the specification. While pushing up or down

on the chain to zero slack.

Torque: 6.08.0kgf-m

Tighten the adjuster.

Torque: 1.82.5kgf-m

Bolts

Adjuste

r

CABLE INSPECTION AND

LUBRICATION

Adjuste

r



Damaged cable sheath may cause

corrosion and interfere with the cable

movement. An unsafe condition may

result so replace such cable as soon as

possible.

3. INSPECTION/ADJUSTMENT

3-16

MX’er SYSTEM

Inspect the cable sheath.

Replace if damage.

Check the cable operation.

Lubricate or replace if unsmooth operation.

LEVER LUBRICATION

Lubricate the pivoting parts of each lever.

FRONT SUSPENSION

LUBRICATION

Inject grease into the nipples using a grease

gun until slight over flow is observed from

the thrust covers.

Hold cable end high and apply several

dro

p

s of lubricant to cable.



Wi



pe off the excess grease.

Nipple

4. LUBRICATION SYSTEM

4-0

MX’er SYSTEM

4

__________________________________________________________________________________

____________________________________________________________________

4

____________________________________________________________________

LUBRICATION SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 4- 2

TROUBLESHOOTING----------------------------------------------------- 4- 2

ENGINE OIL/OIL FILTER ------------------------------------------------ 4- 3

OIL PUMP-------------------------------------------------------------------- 4- 3

4. LUBRICATION SYSTEM

4-1

MX’er SYSTEM

LUBRICATION SYSTEM

Rocker Arm Shaft

Crankshaft

Oil Filter Screen Oil Pump

4. LUBRICATION SYSTEM

4-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The maintenance of lubrication system can be performed with the engine installed in the frame.

• Use care when removing and installing the oil pump not to allow dust and foreign matters to

enter the engine and oil line.

• Do not attempt to disassemble the oil pump. The oil pump must be replaced as a set when it

reaches its service limit.

• After the oil pump is installed, check each part for oil leaks.

SPECIFICATIONS

Item Standard (mm) Service Limit (mm)

Inner rotor-to-outer rotor clearance ⎯ 0.12

Oil pump Outer rotor-to-pump body clearance ⎯ 0.12

Rotor end-to-pump body clearance 0.050.10 0.2

TROUBLESHOOTING

Oil level too low Poor lubrication pressure

• Natural oil consumption • Oil level too low

• Oil leaks • Clogged oil filter or oil passages

• Worn or poorly installed piston rings • Not use the specified oil

• Worn valve guide or seal

4. LUBRICATION SYSTEM

4-3

MX’er SYSTEM

Nu

t

Flywheel

ENGINE OIL/OIL FILTER

OIL LEVEL

Remove the oil dipstick and check the oil

level with the oil dipstick.

If the level is near the lower level, fill to the

upper level with the specified engine oil.

OIL CHANGE

Remove the oil drain plug bolt located on

the bottom of the engine to drain the engine

oil thoroughly.

After the oil has been completely drained,

Install the oil drain plug bolt.

Torque: 2..03.0kgf-m

Refer to page 3-2 to clean the engine oil

filter screen

After the oil has been completely drained,

check the filter screen O-ring for damage

and replace if necessary.

Install the oil filter screen, spring and filter

screen cap.

Torque: 1.02.0kgf-m

Fill with the specified SAE15W40#, API: SG

engine oil to the proper level.

Oil Capacity: At disassembly : 1.0 liter

At change : 0.9 liter

Check for oil leaks and then start the engine

and let it idle for few minutes.

Recheck the oil level.

OIL PUMP

REMOVAL

Remove the right crankcase cover.

Remove the A.C. generator flywheel.

Flywheel holder E021

Flywheel puller E003

Lower Level

Oil Dipstick

Oil Filter Screen Cap

•



Place the motorcycle upright on level

ground for engine oil level check.

• Run the engine for 23 minutes and

check the oil level after the engine is

stopped for 23 minutes.

Upper Level

The engine oil will drain more easily

while the engine is warm.



oil drain plug bol

t

pecial S

4. LUBRICATION SYSTEM

4-4

MX’er SYSTEM

Oil Pump Driven Gea

r

Bolts

Nu

t

Remove the starter idle gear and starter

clutch.

Lock nut socket wrench E009

Remove the two bolts and oil separator

cover.

Remove the oil pump driven gear nut to

remove the oil pump driven gear and drive

chain.

Remove the oil pump mounting two bolts

and the oil pump.

S

t

arter Clutch

Oil Separator Cove

r

Oil Pump

Starter Idle Gea

r

Special

4. LUBRICATION SYSTEM

4-5

MX’er SYSTEM

Outer Roto

r

Outer Roto

r

Inner Roto

r

Pump Body

Screw

DISASSEMBLY

Remove the screw and disassemble the oil

pump.

INSPECTION

Measure the pump body-to-outer rotor

clearance.

Service Limit: 0.12mm

Measure the inner rotor-to-outer rotor

clearance.

Service Limit: 0.12mm

Measure the rotor end-to-pump body

clearance.

Service Limit: 0.2mm

Pump Body

4. LUBRICATION SYSTEM

4-6

MX’er SYSTEM

Screw

Inner Roto

r

Bolts

Pump Cove

r

Outer Roto

r

ASSEMBLY

Dowel Pin

Oil Pum

p

Arrow

Install the outer rotor, inner rotor and pump

shaft into the pump body.

Install the dowel pin.

Install the pump cover by aligning the hole

in the cover with the dowel pin.

Tighten the screw to secure the pump cover.

Make sure that the pump shaft rotates freely

without binding.

INSTALLATION

Install the oil pump into the crankcase.

After the oil pump is installed, tighten the

two mounting bolts.



Insert the pump shaft by aligning the flat

on the shaf at in the inner

rotor.

t with the fl



Install the oil pum

the pum

pump with engine oil before installation.

p with the arrow on

p body facing up and fill the oil

4. LUBRICATION SYSTEM

4-7

MX’er SYSTEM

Install the pump driven gear and drive chain

by aligning the pump driven gear with the

cutout in the pump shaft.

Flywheel

Starter Idle Gea

r

Bolts

Nu

t

Pump Driven Gea

r

Starter Clutch

Install and tighten the pump driven gear nut.

Torque: 0.81.2kgf-m

Install the oil separator cover and tighten

the bolts.

Install the starter idle gear and starter

clutch.

Install the starter clutch nut and tighten it to

specified torque..

Torque: 9.5 kgf-m

Install the gasket and dowel pins.

Install the A.C. generator flywheel.

Install the right crankcase cover.

Torque: 0.81.2kgf-m

Oil Separator Cove

r

Dowel Pin

Gaske

t

Diagonally tighten the bolts in 23

times.



5. FUEL SYSTEM

5-0

MX’er SYSTEM

5

__________________________________________________________________________________

____________________________________________________________________

5

____________________________________________________________________

FUEL SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 5- 2

TROUBLESHOOTING----------------------------------------------------- 5- 3

THROTTLE VALVE DISASSEMBLY/CARBURETOR REMOVAL-- 5- 4

FLOAT/FLOAT VALVE/JETS-------------------------------------------- 5- 5

CARBURETOR INSTALLATION --------------------------------------- 5- 8

FUEL TANK ----------------------------------------------------------------- 5- 9

FUEL VALVE REMOVAL------------------------------------------------ 5- 9

AIR CLEANER -------------------------------------------------------------- 5-10

5. FUEL SYSTEM

5-1

MX’er SYSTEM

5. FUEL SYSTEM

5-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

Gasoline is very dangerous. When working with gasoline, keep sparks and flames away

from the working area.

Gasoline is extremely flammable and is explosive under certain conditions. Be sure to

work in a well-ventilated area.

• Do not bend or twist control cables. Damaged control cables will not operate smoothly.

• When disassembling fuel system parts, note the locations of O-rings. Replace them with new

ones during reassembly.

• Before float chamber disassembly, loosen the drain screw to drain the residual gasoline into a

clean container.

• After the carburetor is removed, plug the intake manifold side with a clean shop towel to prevent

foreign matters from entering.

• When cleaning the carburetor air and fuel jets, the O-rings and diaphragm must be removed first

to avoid damage. Then, clean with compressed air.

• When the motorcycle is not used for over one month, drain the residual gasoline from the float

chamber to avoid erratic idling and clogged slow jet due to deteriorated fuel.

SPECIFICATIONS MX’er 150 MX’er 125

Item Standard Standard

Type PD PD

Venturi dia. φ25 φ25

Float level 14.8mm 14.8mm

Main jet No. 95 95

Adjust method Piston Piston

Idle speed 1700±100rpm 1700±100rpm

Throttle grip free play 14mm 14mm

Air screw opening 2±1/2 2±1/2

5. FUEL SYSTEM

5-3

MX’er SYSTEM

SPECIAL TOOL

Float level gauge

TROUBLESHOOTING

Engine cranks but won’t start Engine lacks power

• No fuel in tank • Clogged air cleaner

• No fuel to carburetor • Faulty carburetor

• Cylinder flooded with fuel • Faulty ignition system

• No spark at plug

• Clogged air cleaner Lean mixture

• Intake air leak • Clogged carburetor fuel jets

• Improper throttle operation • Float level too low

• Intake air leak

Engine idles roughly, stalls or runs poorly • Clogged fuel tank cap breather hole

• Excessively used choke • Kinked or restricted fuel line

• Ignition malfunction

• Faulty carburetor Rich mixture

• Poor quality fuel • Float level too high

• Lean or rich mixture • Clogged air jets

• Incorrect idle speed • Clogged air cleaner

Misfiring during acceleration

• Faulty ignition system

• Faulty carburetor

Backfiring at deceleration

• Float level too low

• Incorrectly adjusted carburetor

• Faulty exhaust muffler

5. FUEL SYSTEM

5-4

MX’er SYSTEM

THROTTLE VALVE DISASSEMBLY

Remove the front cover.

Remove the front fender.

Remove the carburetor cap.

Pull out the throttle valve.

Disconnect the choke knob cable.

Disconnect the throttle cable and remove the

spring from the throttle valve.

Pry off the needle retainer and remove the jet

needle.

Check the throttle valve and jet needle for

wear or damage.

CARBURETOR REMOVAL

Switch the fuel valve OFF.

Loosen the drain screw to drain the gasoline

from the float chamber.

Disconnect the fuel inlet tube and the choke

cable.

Carburetor Cap

Spring

Throttle Cable

Throttle Valve

Clip Needle Retaine

r

Throttle Valve Jet Needle

Choke Cable

• Keep sparks and flames away from the

work area.

• Drain gasoline into a clean container.



5. FUEL SYSTEM

5-5

MX’er SYSTEM

Loosen the air cleaner connecting tube band

screw.

Remove the two carburetor lock nuts.

Remove the carburetor

FLOAT/FLOAT VALVE/JETS

FLOAT/FLOAT VALVE DISASSEMBLY

Remove the float chamber attaching three

screws and remove the float chamber.

Remove the float pin, float and float valve.

FLOAT/FLOAT VALVE INSPECTION

Inspect the float valve seat for wear or

damage.

Inspect the float for damage or fuel level

inside the float chamber.

Lock Nuts

Screw

Screws

Floa

t

Float Pin Float Valve

Float Valve

Float Valve Sea

t

5. FUEL SYSTEM

5-6

MX’er SYSTEM

JETS/AIR SCREW/THROTTLE STOP

SCREW REMOVAL

Remove the main jet, needle jet holder, and

needle jet.

Remove the slow jet.

Remove the air screw and throttle stop

screw.

CAUTIONS !

FUEL RESERVOIR O-RING CHECK

Remove the O-ring.

INSPECTION

Inspect the check the O-ring for damage.

Replace with new ones if necessary

CARBURETOR CLEANING

Blow compressed air through all passages of

the carburetor body.

Air Screw

Slow Je

t

Main Je

t

Throttle Sto

p

Screw

O-ring

Slow Je

t

Air Screw

• Be careful not to damage the jets and

jet holder when removing them.

• Before removal, turn the throttle stop

screw and air screw in and count the

number of turns until they seat lightly

and then make a note of this.

• Do not force the screw against its seat

to avoid seat damage.

• Be sure to install the O-ring in the

reverse order of removal.



S

p

rin

g

Main Je

t

Throttle

Stop Screw

Washe

r

O-rin

g

S

p

rin

g

5. FUEL SYSTEM

5-7

MX’er SYSTEM

SLOW/MAIN JET INSTALLATION

Install the slow jet.

Install the needle jet, needle jet holder and

main jet.

Install the throttle stop screw and air screw

Install the float valve, float and float pin.

FLOAT LEVEL INSPECTION

Turn the carburetor upside down so that the

float will go down to make the float valve

contact the float valve seat.

Then slowly tilt the carburetor and measure

the float level with the float level gauge

while the float pin just contacts with float

valve.

Float Level:

MX’er 150 14.8mm

MX’er 125

When adjusting, carefully bend the float pin.

Check the float for proper operation and then

install the float chamber.

Main Je

t

Slow Je

t

Float Level Gauge

• When installing the air screw, return it

to the original position as noted during

removal

• After the carburetor is installed, be

sure to perform the Exhaust Emission



Throttle Sto

p

Screw

Float Pin

Floa

t

Ai

r

Screw

5. FUEL SYSTEM

5-8

MX’er SYSTEM

CARBURETOR INSTALLATION

Install the carburetor onto the intake

manifold and tighten the two lock nuts.

Torque: 0.81.2kgf-m

Install the air cleaner connecting tube and

tighten the band screw.

THROTTLE VALVE ASSEMBLY

Install the jet needle into the throttle valve

and secure with the needle retainer.

Jet Needle Notch: 4th Notch

(Counted from top to bottom)

Assemble the rubber cover, carburetor cap

and throttle valve spring.

Connect the throttle cable to the throttle

valve.

Install the throttle valve into the carburetor

body.

Connect the accelerating pump cable.

Fully open the throttle and adjust the

accelerating pump cable to align the punch

mark on the accelerating pump arm with the

punch mark on the set plate.

Lock Nu

t

Band Screw

Needle Retaine

r

Clip

Je

t

Needle

Throttle Valve

Spring

Carburetor Cap

Notch

Throttle Valve

Groove

Throttle Stop Screw

Align the groove in the throttle valve

with the throttle stop screw on the

carburetor body.



5. FUEL SYSTEM

5-9

MX’er SYSTEM

Tighten the choke cable.

FUEL TANK

FUEL TANK REMOVAL

Remove the seat.

Remove the center cover.

Remove the right and left front fender.

Switch the fuel valve “OFF”.

Disconnect the fuel tube and remove two

bolts on the end of the fuel tank.

Remove the fuel tank.

FUEL VALVE REMOVAL

Remove the fuel valve and fuel cup.

Screw

Choke Cable

Bolts Fuel Tank

Fuel Valve

Tube

Side

• Keep sparks and flames away from the

work area.

• Wipe off any spilled gasoline.

5. FUEL SYSTEM

5-10

MX’er SYSTEM

Remove the screw on the fuel valve control

switch.

Remove the two screws on the fuel valve

body.

INSPECTION

Inspect the fuel valve strainer for dirt and

clog. Clean if necessary.

Replace the O-rings with new ones if they

are damaged or deteriorated.

AIR CLEANER

REMOVAL

Remove the seat.

Remove the four screws on the air cleaner

case cover and the cover.

Remove the air cleaner screen and element.

Fuel Valve Body

Screws

Air Cleaner Case Cove

r

Washe

r

Cont

r

ol Switch

Control Shaf

t

Rubber Gaske

t

Retaining Ring

6. ENGINE REMOVAL/INSTALLATION

6-0

MX’er SYSTEM

6

__________________________________________________________________________________

____________________________________________________________________

ENGINE REMOVAL/INSTALLATION

____________________________________________________________________

6

SERVICE INFORMATION------------------------------------------------ 6- 1

ENGINE REMOVAL ------------------------------------------------------- 6- 2

ENGINE INSTALLATION ------------------------------------------------ 6- 4

6. ENGINE REMOVAL/INSTALLATION

6-1

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• A floor jack or other adjustable support is required to support and maneuver the engine. Be

careful not to damage the machine body, cables and wires during engine removal.

• Use shop towels to protect the motorcycle body during engine removal.

• Parts requiring engine removal for servicing:

⎯ Crankcase

⎯ Crankshaft

6. ENGINE REMOVAL/INSTALLATION

6-2

MX’er SYSTEM

ENGINE REMOVAL

Drain engine oil and transmission oil.

Remove seat, front cover, center cover,

front fender and rear fender.

Remove the carburetor.

Disconnect the battery negative cable.

Remove the frame body cover.

Disconnect the engine negative cable.

Disconnect the A.C.G. wire connector.

Disconnect the starter motor cable from the

starter relay.

Disconnect the oil recycle tube at the engine

body.

Disconnect the oil recycle tube at the

cylinder head cover.

Loosen the drive belt air cleaner connecting

tube band screw and remove the connecting

tube.

Starter Relay Starter Motor Cable

Oil Recycle Tube

Connecting Tube

Screw

Oil Recycle Tube

A.C.G. Wire Connecto

r

6. ENGINE REMOVAL/INSTALLATION

6-3

MX’er SYSTEM

Disconnect the spark plug high-tension

wire.

Remove the spark plug cap and disconnect

the ignition coil wire from the set plate.

Remove the rear drive chain gear on the

bolts.

Remove the drive chain gear.

Remove the two bolts and two joint lock

nuts attaching the exhaust muffler.

Remove the exhaust muffler.

ENGINE REMOVAL

Remove the engine any connector thing.

Remove the engine back bracket tow bolts.

Ignition Coil Wire

Drive Chain Gea

r

Exhaust Muffle

r

Bolts

6. ENGINE REMOVAL/INSTALLATION

6-4

MX’er SYSTEM

Remove the engine front bracket bolt.

ENGINE HANGER BRACKET

REMOVE

Remove the two bolts on the left engine

hanger bracket.

Remove the left engine hanger bracket.

Remove the engine.

ENGINE INSTALLATION

Install the engine and tighten the engine

mounting bolts.

Torque: 3.54.5kgf-m

Install the removed parts in the reverse

order of removal.

Bol

t

Engine Hanger Bracke

t

Bolts

Route the wires and cables properly.



7. CYLINDER HEAD/VALVES

7-0

MX’er SYSTEM

7

__________________________________________________________________________________

____________________________________________________________________

CYLINDER HEAD/VALVES

____________________________________________________________________

7

SERVICE INFORMATION------------------------------------------------ 7- 2

TROUBLESHOOTING----------------------------------------------------- 7- 3

CAMSHAFT REMOVAL-------------------------------------------------- 7- 4

CYLINDER HEAD REMOVAL ------------------------------------------ 7- 7

CYLINDER HEAD DISASSEMBLY ------------------------------------ 7- 8

CYLINDER HEAD ASSEMBLY----------------------------------------- 7-10

CYLINDER HEAD INSTALLATION ----------------------------------- 7-10

CAMSHAFT INSTALLATION ------------------------------------------- 7-11

7. CYLINDER HEAD/VALVES

7-1

MX’er SYSTEM

7. CYLINDER HEAD/VALVES

7-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The cylinder head can be serviced with the engine installed in the frame.

• When assembling, apply molybdenum disulfide grease or engine oil to the valve guide movable

parts, valve arm and camshaft sliding surfaces for initial lubrication.

• The camshaft is lubricated by engine oil through the cylinder head engine oil passages. Clean and

unclog the oil passages before assembling the cylinder head.

• After disassembly, clean the removed parts and dry them with compressed air before inspection.

• After removal, mark and arrange the removed parts in order. When assembling, install them in

the reverse order of removal.

SPECIFICATIONS

Item Standard (mm) Service Limit (mm)

IN 0.06 ⎯

EX 0.06 ⎯

Cylinder head compression pressure 16kg/cm²

Cylinder head warpage ⎯ 0.05

IN 31.8 31.4

EX 31.53 31.13

Valve rocker arm to shaft clearance 0.090.034 0.1

Valve stem-to-guide IN 0.0100.037 0.06

clearance EX 0.0250.052 0.08

IN 39.4 ⎯

Valve spring free length EX 45.5 ⎯

IN 7.78.9kg(at 33.7mm) ⎯

Valve spring

compressed force EX 19.522.5kg(at 38.4mm) ⎯

IN 1.7 ⎯

Valve spring tilt EX 1.95 ⎯

Valve clearance (cold)

Camshaft cam height

7. CYLINDER HEAD/VALVES

7-3

MX’er SYSTEM

TORQUE VALUES

Cylinder head nut 1.82.2kgf-m Apply engine oil to threads

Valve clearance adjusting nut 1.41.8kgf-m Apply engine oil to threads

Stud bolt 0.71.1kgf-m

SPECIAL TOOLS

Valve spring compressor E040

Tappet adjuster E012

TROUBLESHOOTING

• The poor cylinder head operation can be diagnosed by a compression test or by tracing engine

top-end noises.

Poor performance at idle speed White smoke from exhaust muffler

• Compression too low • Worn valve stem or valve guide

• Damaged valve stem seal

Compression too low

• Incorrect valve clearance adjustment Abnormal noise

• Burned or bend valves • Incorrect valve clearance adjustment

• Incorrect valve timing • Sticking valve or broken valve spring

• Broken valve spring • Damaged or worn camshaft

• Poor valve and seat contact • Worn cam chain guide

• Leaking cylinder head gasket • Worn camshaft and rocker arm

• Warped or cracked cylinder head

• Poorly installed spark plug

Compression too high

• Excessive carbon build-up in combustion

chamber

7. CYLINDER HEAD/VALVES

7-4

MX’er SYSTEM

CAMSHAFT REMOVAL

Remove seat, front cover, center cover.

Front fender, fuel tank and exhaust pipe.

Remove the four cylinder head cover bolts

to remove the cylinder head cover.

Remove the cam chain tensioner cap bolt

and the O-ring.

Turn the cam chain tensioner screw

clockwise to tighten it.

Turn the flywheel counterclockwise so that

the “T” mark on the flywheel aligns with

the index mark on the crankcase to bring the

round hole on the camshaft gear facing up

to the top dead center on the compression

stroke.

Cylinder Head Cove

r

O-ring

Tensioner Screw

Round Hole

Camshaft Gea

r

Bol

t

Punch Marks

Bolts

7. CYLINDER HEAD/VALVES

7-5

MX’er SYSTEM

Remove the four cylinder head nuts and

washers.

Remove the camshaft holder and dowel

pins.

Remove the camshaft gear from the cam

chain and remove the camshaft.

CAMSHAFT INSPECTION

Check each cam lobe for wear or damage.

Measure the cam lobe height.

Service Limits:

IN : 31.40mm replace if below

EX: 31.13mm replace if below

Cam Chain Camshaft Gea

r

Camshaft Holde

r

Nu

t

Washe

r

Dowel PinsCamshaf

t

Diagonally loosen the cylinder head nuts

in 2 or 3 times.



7. CYLINDER HEAD/VALVES

7-6

MX’er SYSTEM

Check each camshaft bearing for play or

damage. Replace the camshaft assembly

with a new one if the bearings are noisy or

have excessive play.

CAMSHAFT HOLDER DISASSEMBLY

Remove the bolt attaching the stop plate.

Take out the valve rocker arm shafts using a

5mm bolt.

Remove the valve rocker arms.

CAMSHAFT HOLDER INSPECTION

Inspect the camshaft holder, valve rocker

arms and rocker arm shafts for wear or

damage.

Measure the I.D. of each valve rocker arm.

Measure each rocker arm shaft O.D.

Measure arm to shaft clearance.

Replace as a set if out of specification.

Service limits: 0.10mm

Rocker Ar

m

Bol

t

Rocker Arm Shaf

t

Camshaft Holde

r

Rocker Arm Shafts

If the valve rocker arm contact surface is

worn, check each cam lobe for wear or

damage.



Camshaft Bearin

g

s

7. CYLINDER HEAD/VALVES

7-7

MX’er SYSTEM

CYLINDER HEAD REMOVE

Remove the camshaft.

Remove the carburetor.

Remove the exhaust muffler.

Remove the carburetor intake manifold.

Remove the two cylinder head bolts.

Remove the cylinder head.

Remove the dowel pins and cylinder head

gasket.

Remove the cam chain guide.

Remove all gasket material from the

cylinder mating surface.

Intake Manifold

Cylinder Head

Dowel Pins

Cam Chain Guide

C

y

linder Head Gaske

t

Bolts

• Avoid damaging the cylinder mating

surface.

• Be careful not to drop any gasket

material into the engine.



7. CYLINDER HEAD/VALVES

7-8

MX’er SYSTEM

CYLINDER HEAD

DISASSEMBLY

Remove the valve spring cotters, retainers,

springs, spring seats and valve stem seals

using a valve spring compressor.

Valve Spring Compressor E040

Remove carbon deposits from the

combustion chamber.

Clean off any gasket material from the

cylinder head mating surface.

INSPECTION

CYLINDER HEAD

Check the spark plug hole and valve areas

for cracks.

Check the cylinder head for warpage with a

straight edge and feeler gauge.

Service Limit: 0.05mm repair or replace if

over

VALVE /VALVE GUIDE

Inspect each valve for bending, burning,

scratches or abnormal stem wear.

Check valve movement in the guide.

Measure each valve stem O.D.

Valve Spring Compresso

r

• Be sure to compress the valve springs

with a valve spring compressor.

• Mark all disassembled parts to ensure

correct reassembly.



Valve S

p

rin

g

Com

p

ressor

Be careful not to damage the cylinder

head mating surface.



Special

7. CYLINDER HEAD/VALVES

7-9

MX’er SYSTEM

Measure each valve guide I.D.

Subtract each valve stem O.D. from the

corresponding guide I.D. to obtain the

stem-to-guide clearance.

Service limits: IN : 0.06mm replace if over

EX: 0.08mm replace if over

VALVE SPRING FREE LENGTH

Measure the free length of the inner and

outer valve springs.

Inner : 39.4mm replace if below

Outer: 45.5mm replace if below

Measure compressed force (valve spring)

and installed length.

Replace if out of specification.

Service limits:

IN : 7.78.9kg (at 33.7mm)

EX : 19.522.5kg (at 38.4mm)

Measure the spring tilt.

Replace if out of specification.

Service limits: IN : 1.7mm

EX : 1.95mm

If the ste

m

-to-guide clearance exceeds

the service limits, replace the cylinder

head as necessary.



7. CYLINDER HEAD/VALVES

7-10

MX’er SYSTEM

CYLINDER HEAD ASSEMBLY

Install the valve spring seats and valve stem

seals.

Lubricate each valve stem with engine oil

and insert the valves into the valve guides.

Install the valve springs and retainers.

Compress the valve springs using the valve

spring compressor, then install the valve

cotters.

Valve Spring Compressor E040

Tap the valve stems gently with a plastic

hammer for 23 times to firmly seat the

cotters.

CYLINDER HEAD

INSTALLATION

Install the dowel pins and a new cylinder

head gasket.

Install the cam chain guide.

Be sure to install new valve stem seals.



Valve Spring Compresso

r

Gaske

t

Cam Chain Guide

Dowel Pins

• When assembling, a valve spring

comp



ressor must be used.

• Install the cotters with the pointed ends

facing down from the upper side of the

cylinder head.

Special

Be careful not to damage the valves.



7. CYLINDER HEAD/VALVES

7-11

MX’er SYSTEM

Install two cylinder head bolts do not

tighten completely.

Install the cylinder head.

Torque: Stud Bolts :0.81.2kgf-m

CAMSHAFT HOLDER ASSEMBLY

Install the exhaust valve rocker arm to the

“EX” mark side of the camshaft holder.

Install the intake valve rocker arm and the

rocker arm shafts.

Tighten the bolt attaching stop plate.

CAMSHAFT INSTALLATION

Turn the flywheel so that the “T” mark on

the flywheel aligns with the index mark on

the crankcase.

Keep the round hole on the camshaft gear

facing up and align the punch marks on the

camshaft gear with the cylinder head

surface (Position the intake and exhaust cam

lobes down.) and install the camshaft onto

the cylinder head.

Install the cam chain over the camshaft

gear.

Install the dowel pins.

Dowel Pins

Valve Rocker Ar

m

C

y

linder Head

Punch Marks

Camshaft Holde

r

Cam Chain Round Hole Camshaft Gea

r

Bolts

• Align the cutout on the front end of the



intake valve rocker arm

valve rocker arm

shaft with the

bolt of the camshaft holder.

• Align the cross cutout on the exhaust

shaft with the bolt of

the camshaft holder.

7. CYLINDER HEAD/VALVES

7-12

MX’er SYSTEM

Install the camshaft holder, washers and

nuts on the cylinder head.

Tighten the four cylinder head nuts, then

tighten two cylinder head bolts compeletly.

Torque: Cylinder head nut: 1.82.2kgf-m

Adjust the valve clearance.

Turn the cam chain tensioner screw

counter-clockwise to release it.

Apply engine oil to a new O-ring and install

it.

Tighten the cam chain tensioner cap bolt.

Install a new cylinder head cover O-ring

and install the cylinder head cover.

Install and tighten the cylinder head cover

bolts.

Nu

t

Camshaft Holde

r

Washe

r

Tensioner Screw

Cylinder Head Cove

r

Bol

t

• Apply engine oil to the threads of the

cylinder head nuts.



• Diagonally tighten the cylinder head

nuts in 23 times.

Be sure to install the O-ring into the

groove properly.



Be sure to install the O-ring into the

groove properly.



8. CYLINDER/PISTON

8-0

MX’er SYSTEM

8

__________________________________________________________________________________

____________________________________________________________________

CYLINDER /PISTON

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 8- 2

TROUBLESHOOTING----------------------------------------------------- 8- 2 8

CYLINDER REMOVAL --------------------------------------------------- 8- 4

PISTON REMOVAL-------------------------------------------------------- 8- 4

PISTON INSTALLATION------------------------------------------------- 8- 8

CYLINDER INSTALLATION -------------------------------------------- 8- 8

8. CYLINDER/PISTON

8-1

MX’er SYSTEM

8. CYLINDER/PISTON

8-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The cylinder and piston can be serviced with the engine installed in the frame.

• After disassembly, clean the removed parts and dry them with compressed air before inspection.

TROUBLESHOOTING

• When hard starting or poor performance at low speed occurs, check the crankcase breather for

white smoke. If white smoke is found, it means that the piston rings are worn, stuck or broken.

Compression too low or uneven

compression Excessive smoke from exhaust muffler

• Worn, stuck or broken piston rings • Worn or damaged piston rings

• Worn or damaged cylinder and piston • Worn or damaged cylinder and piston

Compression too high Abnormal noisy piston

• Excessive carbon build-up in combustion • Worn cylinder, piston and piston rings

chamber or on piston head • Worn piston pin hole and piston pin

8. CYLINDER/PISTON

8-3

MX’er SYSTEM

SPECIFICATIONS

Mx’er 150 Standard (mm) Service Limit (mm)

I.D. 62.0362.045 ⎯

Warpage ⎯ 0.05

Cylindricity ⎯ 0.05

True roundness ⎯ 0.05

Rin

g

-to-

g

roove Top 0.0150.055 0.09

clearance Second 0.0150.055 0.09

Top 0.100.25 0.5

Piston, Ring end gap Second 0.100.25 0.5

piston ring Oil side rail 0.20.7 ⎯

Piston O.D. 61.9662 ⎯

Piston O.D. measuring position 5mm from bottom of skirt ⎯

. Piston-to-cylinder clearance 0.0100.040 0.1

Piston pin hole I.D. 15.00215.008 15.04

Piston pin O.D 14.99415.000 14.96

Piston-to-piston pin clearance 0.0020.014 0.02

Connecting rod small end I.D. bore 15.01615.034 15.06

Cylinde

r

Mx’er 125 Standard (mm) Service Limit (mm)

I.D. 56.5356.545 ⎯

Warpage ⎯ 0.05

Cylindricity ⎯ 0.05

True roundness ⎯ 0.05

Rin

g

-to-

g

roove Top 0.0150.055 0.09

clearance Second 0.0150.055 0.09

Top 0.100.25 0.5

Piston, Ring end gap Second 0.100.25 0.5

piston ring Oil side rail 0.20.7 ⎯

Piston O.D. 56.4656.5 ⎯

Piston O.D. measuring position 5mm from bottom of skirt ⎯

. Piston-to-cylinder clearance 0.0100.040 0.1

Piston pin hole I.D. 15.00215.008 15.04

Piston pin O.D 14.99415.000 14.96

Piston-to-piston pin clearance 0.0020.014 0.02

Connecting rod small end I.D. bore 15.01615.034 15.06

Cylinde

r

8. CYLINDER/PISTON

8-4

MX’er SYSTEM

CYLINDER REMOVAL

Turn the cam chain tension screw clockwise

to tighten it.

Remove the two bolts on the cam chain

tension.

Remove the cylinder head.

Remove the cam chain guide.

Remove the cylinder base bolts.

Remove the cylinder

.

Remove the cylinder gasket and dowel pins.

Clean any gasket material from the cylinder

surface.

PISTON REMOVAL

Remove the piston pin clip.

Press the piston pin out of the piston and

remove the piston.

Bol

t

Cylinde

r

Dowel Pins

Piston

Piston Pin Clip

Place a clean shop towel in the crankcase

to keep the piston pin clip from falling

into the crankcase.



8. CYLINDER/PISTON

8-5

MX’er SYSTEM

Inspect the piston, piston pin and piston

rings.

Remove the piston rings.

Clean carbon deposits from the piston ring

grooves.

Install the piston rings onto the piston and

measure the piston ring-to-groove clearance.

Service Limits: Top: 0.09mm replace if

over

2nd: 0.09mm replace if

over

Remove the piston rings and insert each

piston ring into the cylinder bottom.

Measure the piston ring end gap.

Service Limit: 0.5mm replace if over

Measure the piston pin hole I.D.

Service Limit: 15.04mm replace if over

Take care not to damage or break the

piston rings during removal.



Use the piston head to push each piston

ring into the cylinder.



8. CYLINDER/PISTON

8-6

MX’er SYSTEM

Measure the piston pin O.D.

Service Limit: 14.96mm replace if below

Measure the piston O.D.

Piston O.D.: 61.9662mm (MX’er 150)

Piston O.D.: 56.4656.5mm (MX’er 125)

Measure the piston-to-piston pin clearance.

Service Limit: 0.02mm replace if over

CYLINDER INSPECTION

Inspect the cylinder bore for wear or damage.

Measure the cylinder I.D. at three levels of

top, middle and bottom at 90° to the piston

pin (in both X and Y directions).

Cylinder I.D.:

62.0362.045mm (MX’er

150)

56.5356.545mm (MX’er

125)

Measure the cylinder-to-piston clearance.

Service Limit: 0.1mm repair or replace if

over

The true roundness is the difference

between the values measured in X and Y

directions. The cylindricity (difference

between the values measured at the three

levels) is subject to the maximum value

calculated.

Service Limits:

True Roundness: 0.05mm repair or replace

if over

Cylindricity: 0.05mm repair or replace if

over

Take measurement at 5mm from the

bottom and 90° to the piston pin hole.



Top

Middle

Botto

m

8. CYLINDER/PISTON

8-7

MX’er SYSTEM

Inspect the top of the cylinder for warpage.

Service Limit: 0.05mm repair or replace if

over

Measure the connecting rod small end I.D.

Service Limit: 15.06mm replace if over

PISTON RING INSTALLATION

Install the piston rings onto the piston.

Apply engine oil to each piston ring.

• Be careful not to damage or break the

piston and piston rings.

• All rings should be installed with the

markings facing up.

• After installing the rings, they should

rotate freely without sticking.



Second

Top

Side Rail

Oil Ring

8. CYLINDER/PISTON

8-8

MX’er SYSTEM

PISTON INSTALLATION

Remove any gasket material from the

crankcase surface.

Install the piston, piston pin and a new

piston pin clip.

CYLINDER INSTALLATION

Install the dowel pins and a new cylinder

gasket on the crankcase.

Coat the cylinder bore, piston and piston

rings with clean engine oil.

Carefully lower the cylinder over the piston

by compressing the piston rings.

Install the cam chain tension.

Tighten the cam chain tension bolts.

Be careful not to drop foreign matters

into the crankcase.



Piston

Gaske

t

Cylinde

r

Piston Pin

Piston Pin Clip

• Position the piston “IN” mark on the

intake valve side.

• Place a clean shop towel in the

crankcase to keep the piston pin clip

from falling into the crankcase.



• Be careful not to damage or break the

piston rings.

• Stagger the ring end gaps at 120° to the

piston pin.



Bolts

8. CYLINDER/PISTON

8-9

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS

9-0

MX’er SYSTEM

9

DRIVE AND DRIVEN PULLEYS

SERVICE INFORMATION.................................................................... 9-2

TROUBLESHOOTING........................................................................... 9-2

LEFT CRANKCASE COVER ................................................................ 9-3

DRIVE PULLEY.....................................................................................9-3

CLUTCH/DRIVEN PULLEY.................................................................9-3

9

9. DRIVE AND DRIVEN PULLEYS

9-1

MX’er SYSTEM

5.5kg-

m

5.5kg-

m

5.5kg-

m

9. DRIVE AND DRIVEN PULLEYS

9-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The drive pulley, clutch and driven pulley can be serviced with the engine installed in the frame.

• Avoid getting grease and oil on the drive belt and pulley faces. Remove any oil or grease from

them to minimize the slipping of drive belt and drive pulley.

SPECIFICATIONS

Ite

m

Standard

(

mm

)

Service Limit

(

mm

)

Movable drive face bushin

g

I.D. 27.0



27.021 27.06

Drive face collar O.D. 26.97



26.99 226.94

Drive belt width 20.0



21.0 19.0

Clutch linin

g

thickness

⎯

2.0

Clutch outer I.D. 130.0



130.2 130.5

Driven face s

p

rin

g

free len

g

th

⎯

83.2

Driven face O.D. 33.965



33.485 33.94

Movable driven face I.D. 34.000



34.025 34.06

Wei

g

ht roller O.D. 20.95



21.1 20.42

TORQUE VALUES

Drive face nut 5.56.5kgf-m

Clutch outer nut 5.06.0kgf-m

SPECIAL TOOLS

Universal holder E017 Clutch spring compressor E027

Bearing puller E008 Oil seal and bearing install E014

TROUBLESHOOTING

Engine starts but motorcycle won’t move Lack of power

• Worn drive belt • Worn drive belt

• Broken ramp plate • Weak driven face spring

• Worn or damaged clutch lining • Worn weight roller

• Broken driven face spring • Fouled drive face

Engine stalls or motorcycle creeps

• Broken clutch weight spring

9. DRIVE AND DRIVEN PULLEYS

9-3

MX’er SYSTEM

LEFT CRANKCASE COVER

REMOVAL

Loosen the drive belt air tube band screw.

Remove the left crankcase cover bolts and

left crankcase cover.

Remove the gasket and dowel pins.

DRIVE PULLEY

REMOVAL

Hold the drive pulley using an universal

holder and remove the drive face nut and

starting ratchet.

Remove the drive pulley face.

Universal Holder E017

CLUTCH/DRIVEN PULLEY

Remove the drive pulley and drive belt.

Hold the clutch outer with the flywheel

holder and remove the clutch outer nut.

Remove the clutch outer.

Remove the clutch/driven pulley and drive

belt.

Universal Holder E017

Air Tube Band

Screw

Left Crankcase Cove

r

Bolts

Drive Pulley Face

Nu

t

Universal Holde

r

Clutch Oute

r

Universal Holde

r

Special

9. DRIVE AND DRIVEN PULLEYS

9-4

MX’er SYSTEM

INSPECTION

Check the drive belt for cracks, separation or

abnormal or excessive wear.

Measure the drive belt width.

Service Limit: 17.0mm replace if below

Remove the movable drive face assembly.

Remove the drive pulley collar.

DISASSEMBLY

Remove the ramp plate.

Remove the weight rollers.

Use specified genuine parts for

replace-ment.



Drive Pulley Colla

r

Movable Drive Face Assembly

Ramp Plate

Weight Rollers

9. DRIVE AND DRIVEN PULLEYS

9-5

MX’er SYSTEM

INSPECTION

Check each weight roller for wear or damage.

Measure each weight roller O.D.

Service Limit: 20.42mm replace if below.

Measure the movable drive face bushing I.D.

Service Limit: 27.06mm replace if over

Check the drive pulley bushing for wear or

damage.

Measure the O.D. of the drive pulley bushing

sliding surface.

Service Limit: 26.94mm replace if below

9. DRIVE AND DRIVEN PULLEYS

9-6

MX’er SYSTEM

ASSEMBLY

Install the weight rollers into the movable

drive face.

Install the ramp plate.

Weight Rolle

r

Ramp Plate

9. DRIVE AND DRIVEN PULLEYS

9-7

MX’er SYSTEM

Insert the drive pulley collar into the movable

drive face.

INSTALLATION

Install the movable drive face onto the

crankshaft.

INSPECTION

Inspect the clutch outer for wear or damage.

Measure the clutch outer I.D.

Service Limit: 130.5mm replace if over

CLUTCH/DRIVEN PULLEY

DISASSEMBLY

Drive Pulley Colla

r

Movable Drive Face Assembly

Clutch

Driven Pulley

9. DRIVE AND DRIVEN PULLEYS

9-8

MX’er SYSTEM

Hold the clutch/driven pulley assembly with

the clutch spring compressor.

Clutch Spring Compressor E027

Set the clutch spring compressor in a vise and

remove the clutch drive plate nut.

Loosen the clutch spring compressor and

disassemble the clutch/driven pulley assembly.

Remove the seal collar.

Check the driven face for wear or damage.

Measure the clutch lining thickness.

Service Limit: 2.0mm replace if below

Pull out the guide roller pins and guide rollers.

Remove the movable driven face from the

driven face.

Clutch Spring Compresso

r

Be sure to use a clutch spring

comp



ressor to avoid spring damage.

Special

Lock Nut Wrench

Guide Roller Pin

O-ring

Movable Driven Face

9. DRIVE AND DRIVEN PULLEYS

9-9

MX’er SYSTEM

Remove the oil seal from the movable driven

face.

INSPECTION

Measure the driven face spring free length.

Service Limit: 83.2mm replace if below

Check the driven face for wear or damage.

Measure the driven face O.D.

Service Limit: 33.94mm replace if below

Check the movable driven face for wear or

damage.

Measure the movable driven face I.D.

Service Limit: 34.06mm replace if over

Oil Seal

9. DRIVE AND DRIVEN PULLEYS

9-10

MX’er SYSTEM

DRIVEN PULLEY FACE BEARING

REPLACEMENT

Drive the inner needle bearing out of the

driven pulley face.

Remove the snap ring and drive the outer

bearing out of the driven face.

Apply grease to the outer bearing.

Drive a new outer bearing into the driven face

with the sealed end facing up.

Bearing Puller E008

Seat the snap ring in its groove.

Apply grease to the driven face bore areas.

Press a new needle bearing into the driven

face.

Oil Seal And Bearing Install E014

CLUTCH DISASSEMBLY

Remove the circlips and retainer plate to

disassemble the clutch.

Inner Bearing

Discard the removed bearing and replace

with a new one.



Outer Bearing

Discard the removed bearing and replace

with a new one.



Special

Pack all bearing cavities with 99.5g

grease.

Specified grease: Heat resistance 230°C



Special

Retainer Plate

Circlip

Clutch Lining

Keep grease off the clutch linings.



9. DRIVE AND DRIVEN PULLEYS

9-11

MX’er SYSTEM

CLUTCH / DRIVEN PULLEY ASSEMBLY

9. DRIVE AND DRIVEN PULLEYS

9-12

MX’er SYSTEM

Install the damper rubbers on the drive plate

pins.

Install the clutch weights/shoes and clutch

springs onto the drive plate.

Install the retainer plate and secure with the

circlips.

CLUTCH/DRIVEN PULLEY ASSEMBLY

Clean the driven pulley faces and remove any

grease from them.

Install the oil seal onto the moveable driven

face.

Apply grease to the Oil seal and install them

onto the moveable driven face.

Install the movable driven face onto the

driven face.

Apply grease to the guide rollers and guide

roller pins and then install them into the holes

of the driven face.

Install the seal collar.

Remove any excessive grease.

Set the driven pulley assembly, driven face

spring and clutch assembly onto the clutch

spring compressor.

Retainer Plate

Drive Plate

Springs

Clutch Wei

g

hts/Shoes Circlip

Movable Driven Face

Oil Seal

Guide Roller Pin

Driven Face

Be sure to clean the driven face off any

grease.



Align the flat surface of the

d

riven face

with the flat on the clutch drive plate.



9. DRIVE AND DRIVEN PULLEYS

9-13

MX’er SYSTEM

Compress the clutch spring compressor and

install the drive plate nut.

Set the clutch spring compressor in a vise and

tighten the drive plate nut to the specified

torque.

Torque: 5.06.0kgf-m

Clutch Spring Compressor E027

INSTALLATION

Install the clutch/driven pulley onto the drive

shaft.

Install the clutch outer.

Hold the clutch outer with the flywheel

holder.

Install and tighten the clutch outer nut.

Torque: 5.5kg-m

Universal Holder E017

Install the drive belt.

Install the drive pulley face, starting ratchet

and drive face nut.

T orque: 5.56.5kgf-m

Clutch Spring Compresso

r



Be sure to use a clutch spring compressor to avoid spring damage.

Special Lock Nut Wrench

Clutch

Keep grease off the drive shaft.



Driven Pulley

Clutch Oute

r

Universal Holde

r

Drive Pulley

Special

Universal Holde

r

Nu

t

Wh



en installing the drive pulley face,

com ress it to let the drive belt move

downward to the lowest position so that the

drive pulley can be tightened.

Install the starting ratchet by aligning the

starting ratchet teeth with the crankshaft

teeth.

Do not get oil or grease on the drive belt or

pulley faces.

p

9. DRIVE AND DRIVEN PULLEYS

9-14

MX’er SYSTEM

Install the left crankcase cover and tighten the

cover bolts diagonally.

Connect the drive belt air tube and tighten the

band screw.

Left Crankcase Cove

r

Screw

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-0

MX’er SYSTEM

10

__________________________________________________________________________________

____________________________________________________________________

FINAL REDUCTION/TRANSMISSION SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 10- 2

TROUBLESHOOTING----------------------------------------------------- 10- 2

FINAL REDUCTION DISASSEMBLY --------------------------------- 10- 3

FINAL REDUCTION INSPECTION------------------------------------- 10- 4

TRANSMISSION GEARS/CRANKSHAFT REMOVAL------------- 10- 6

FINAL REDUCTION INSTALLATION -------------------------------- 10- 7

10

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-1

MX’er SYSTEM

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• When replacing the drive shaft, use a special tool to hold the bearing inner race for this operation.

SPECIFICATIONS

Specified Oil: GEAR OIL SAE 90#

Oil Capacity: At change : 0.2 liter

At disassembly : 0.4 liter

TORQUE VALUES

Transmission case cover bolt 0.81.2kgf-m

SPECIAL TOOLS

Flywheel holder E021

Flywheel puller E005

Lock nut socket wrench E009

TROUBLESHOOTING

Engine starts but motorcycle won‘t move

• Damaged transmission

• Seized or burnt transmission

Oil leaks

• Oil too rich

• Worn or damaged oil seal

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-3

MX’er SYSTEM

FINAL REDUCTION DISASSEMBLY

Drain engine oil and transmission gear oil

into a clean container.

Remove the engine.

Remove the right crankcase cover.

Remove the shift gear spindle.

Remove the flywheel and starter clutch.

Remove the balance gear oil pump and starter

motor.

Remove the left case bolt.

Remove the transmission case cover

attaching bolts.

Fl

y

wheel

Bolts

Starter Moto

r

Shift Gear S

p

indle

Bol

t

Oil Pum

p

Balance Gea

r

Bol

t

Crankcase Cove

r

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-4

MX’er SYSTEM

Remove gasket and two dowel pins.

FINAL REDUCTION/

TRANSMISSION INSPECTION

Inspect the change gear shaft for wear,

damage or seizure.

Check the transmission operation.

Repair if unsmooth operation.

Remove the plug.

Dowel Pins

Change Gear Shaf

t

Plug

Gaske

t

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-5

MX’er SYSTEM

Shift Cam Stoppe

r

Remove spring, washer and shift cam

stopper.

Remove the transmission fork shaft and

transmission fork.

Measure the transmission fork shaft O.D.

Service Limit: 11.936

Measure the transmission fork shaft hole I.D.

Service Limit: 12.058

Plug

Transmission fork

Transmission fork shaf

t

Washe

r

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-6

MX’er SYSTEM

Check the shift cam groove and shift cam

gear.

Replace if wear or damage.

TRANSMISSION GEARS/

CRANKSHAFT REMOVAL

Remove the final gear and main shaft.

GEAR/SHAFT COLLAR INSPECTION

Check each gear and gear teeth for wear,

damage, or poor lubrication.

Remove the counter shaft.

Countershaf

t

Driver Shaf

t

Countershaf

t

Main Shaf

t

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-7

MX’er SYSTEM

FINAL REDUCTION INSPECTION

Inspect the countershaft and gear for wear or

damage.

Inspect the drive shaft and gear for wear or

damage.

Check the left crankcase bearings for

excessive play and inspect the oil seal for

wear or damage.

Inspect the final shaft gear for wear or

damage.

Check the right crankcase bearings for

excessive play and inspect the oil seal for

wear or damage.

FINAL REDUCTION

INSTALLATION

Install the final gear and final shaft into the

left crankcase.

Install the countershaft and gear into the left

crankcase.

Install the main shaft and gear into the left

crankcase.

Countershaf

t

Bearing

Drive Shaf

t

Final Shaft Gea

r

Left Crankcase

Drive Shaf

t

Bearing Main Shaf

t

Bearing

Main Shaf

t

Bearing

Countershaf

t

Bearing

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-8

MX’er SYSTEM

Install the shift cam into the left crankcase.

Install the transmission fork to the main shaft

gear and install the transmission fork guide

pin into the shift cam groove.

Install the transmission fork shaft into the left

crankcase.

Install the change gear shaft by aligning the

punch mark between with the punch mark of

the shift cam gear.

Install shift cam stopper, spring, washer and

plug and tighten the plug.

Transmission Fork

Shift ca

m

Transmission Fork Shaf

t

Mark

Plug

10. FINAL REDUCTION/

TRANSMISSION SYSTEM

10-9

MX’er SYSTEM

Install the dowel pins and a new gasket onto

the right crankcase.

Tighten the crankcase attaching bolts.

Torque: 0.81.2kgf-m

Tighten the left crankcase attaching bolt.

Install the shaft gear, balance gear, oil pump,

starter clutch and flywheel.

Install and tighten the right case cover bolt.

Install the shift gear spindle.

Install the cylinder.

Specified Gear Oil:

KYMCO SIGMA GEAR OIL 90#

Oil Capacity:

At disassembly : 0.4 liter

At change : 0.2 liter

Install and tighten the oil check bolt.

Torque: 0.81.2kgf-m

Bolts

Cylinde

r

Oil Filler Bol

t

Shift Gear Spindle Right Case Cove

r

11. CRANKSCASE/CRANKSHAFT/

BALANCE SHAFT

11-0

MX’er SYSTEM

11

__________________________________________________________________________________

____________________________________________________________________

CRANKCASE/CRANKSHAFT/BALANCE SHAFT

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 11- 2

TROUBLESHOOTING----------------------------------------------------- 11- 2

CRANKCASE SEPARATION -------------------------------------------- 11- 3

CRANKSHAFT INSPECTION-------------------------------------------- 11- 4

CRANKCASE/BALANCE SHAFT ASSEMBLY---------------------- 11- 5

11

11. CRANKCASE/CRANKSHAFT/

BALANCE SHAFT

11-1

MX’er SYSTEM

11. CRANKSCASE/CRANKSHAFT/

BALANCE SHAFT

11-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• This section covers crankcase separation to service the crankshaft. The engine must be

removed for this operation.

• The following parts must be removed before separating the crankcase.

−Cylinder head (ÖSection 7)

−Cylinder/piston (ÖSection 8)

−Drive and driven pulleys (ÖSection 9)

−A.C. generator (ÖSection 4)

−Carburetor/air cleaner (ÖSection 5)

−Starter motor (ÖSection 16)

−Oil pump (ÖSection 4)

SPECIFICATIONS

Ite

m

Standard (mm) Service Limit (mm)

Connecting rod big end side clearance 0.100.35 0.55

Crankshaft Connecting rod big end radial clearance 00.008 0.05

Run out ⎯ 0.10

TORQUE VALUES

Crankcase bolt 0.81.2kgf-m

Cam chain tensioner slipper bolt 0.81.2kgf-m

Cam chain cover bolt 0.81.2kgf-m

TROUBLESHOOTING

Excessive engine noise

Excessive bearing play

11. CRANKCASE/CRANKSHAFT/

BALANCE SHAFT

11-3

MX’er SYSTEM

CRANKCASE SEPARATION

Remove the left and right crankcase

attaching bolts. (Section 10)

Separate the left and right crankcase halves.

Remove the gasket and dowel pins.

Remover balance shaft from the left

crankcase.

Dowel Pins

Crankcase Bolts

Gaske

t

Do not damage the crankcase gasket

surface.



Balance Shaf

t

Crankshaf

t

11. CRANKSCASE/CRANKSHAFT/

BALANCE SHAFT

11-4

MX’er SYSTEM

Remove the crankshaft and cam chain from

the left crankcase.

Clean off all gasket material from the

crankcase mating surfaces.

CRANKSHAFT INSPECTION

Measure the connecting rod small end I.D.

Service Limit: 15.06 mm replace if over

Measure the connecting rod big end side

clearance.

Service Limit: 0.55mm replace if over

Gaske

t

Avoid damaging the crankcase mating

surfaces.



11. CRANKCASE/CRANKSHAFT/

BALANCE SHAFT

11-5

MX’er SYSTEM

Turn the crankshaft bearings and check for

excessive play.

Measure the crankshaft bearing play.

Service Limit:

Axial : 0.20mm replace if over

Radial : 0.05mm replace if over

Measure the crankshaft run out.

Service Limit: 0.10mm replace if over

CRANKCASE/BALANCE SHAFT

ASSEMBLY

Install the cam chain into the left crankcase.

Install the crankshaft and balance shaft into

the left crankcase.

Install the right and left crankcase.(10-8)

Tighten crankcase attach bolts.

Play

Radial

Axial

Crankshaf

t

Balance Shaf

t

Ri

g

ht Crankcase

Left Crankcase

11. CRANKSCASE/CRANKSHAFT/

BALANCE SHAFT

11-6

MX’er SYSTEM

Align the mark on the balance gear with the

mark on the crankshaft gear.

Install the right and left case cover.

.

Install the cylinder.

Ri

g

ht Case Cove

r

Mark

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-0

MX’er SYSTEM

12

__________________________________________________________________________________

____________________________________________________________________

FRONT WHEEL/FRONT BRAKE/

FRONT SUSPENSION\STEERING SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 12- 2

TROUBLESHOOTING----------------------------------------------------- 12- 3

FRONT WHEEL------------------------------------------------------------- 12- 4

FRONT BRAKE ------------------------------------------------------------- 12- 7

FRONT SUSPENSION ----------------------------------------------------- 12- 9

STEERING SYSTEM------------------------------------------------------- 12-13

12

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-1

MX’er SYSTEM

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• Remove the machine frame covers before removing the front wheel. Jack the machine front

wheel off the ground and be careful to prevent the machine from falling down.

• During servicing, keep oil or grease off the brake drum and brake linings.

• Inspect the brake system before riding.

SPECIFICATIONS

Ite

m

Standard

(

mm

)

Service Limit

(

mm

)

Radial

⎯

2.0

Axial

⎯

2.0

Front brake drum I.D 110 111

Front brake linin

g

thickness 4 1.5

Tie rod len

g

th 266.5

⎯

Ro

d

-end

(

tie rod

)

an

g

le 180º

⎯

Front wheel rim run out

TORQUE VALUES

Steering stem nut 6.08.0kgf-m

Swing arm nut 4.05.0kgf-m

Front wheel nut 6.08.0kgf-m

Front wheel hub nut 6.08.0kgf-m

Front shock absorber upper

mount bolt 3.54.5kgf-m

Front shock absorber lower

mount bolt 3.54.5kgf-m

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-3

MX’er SYSTEM

SPECIAL TOOLS

Oil seal and bearing install E014

TROUBLESHOOTING

Hard steering (heavy) Front wheel wobbling

•Insufficient tire pressure • Bent rim

• Excessive wheel bearing play

• Bent spoke plate

• Faulty tire

Steers to one side or does not track straight • Improperly tightened axle nut

• Uneven front shock absorbers Soft front shock absorber

• Bent front arm • Weak shock springs

• Bent steering knuckle • Insufficient damper oil

Poor brake performance Front shock absorber noise

• Incorrectly adjusted brake • Slider bending

• Worn brake linings • Loose arm fasteners

• Contaminated brake lining surface • Lack of lubrication

• Worn brake shoes at cam contacting area

• Worn brake drum

• Poorly connected brake arm

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-4

MX’er SYSTEM

FRONT WHEEL

REMOVAL

Place the machine on a level place.

Remove four nuts attaching the wheel panel

and front wheel.

Elevate the front wheels by placing a

suitable stand under the frame.

Remove the cotter pin.

Remove nut attaching the wheel hub and

washer.

Remove the collar and wheel hub.

FRONT BRAKE DISASSEMBLY

Loosen the lock nut and tighten the adjuster

nut at brake lever. (Refer to the “FRONT

BRAKE ADJUSTMENT” section in the

CHAPTER 3.).

Disconnect the front brake cable from brake

cam lever and remove the brake panel.

Remove the brake shoes.

REMOVE

Remove brake shoes and springs.

Remove the bolt attaching camshaft lever

and remove camshaft lever.

Remove the wear indicator, camshaft and

O-

rings

Nu

t

Camshaft leve

r

Brake Cable

Support the machine securely so there is

no dan

g

er of it fallin

g

over.



Wheel Hub

Front Wheel

Colla

r

Wheel Panel Nuts Hub Nu

t

Brake Panel

Nuts

Washe

r

Wear Indicato

r

Brake Panel

Brake Shoes

S

p

rin

g

s

Brake Shoes

O-rin

g

s

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-5

MX’er SYSTEM

Measure the wheel run out.

Replace wheel or check bearing play if out

of specification

Rim run out limits:

Vertical: 2.0mm

Lateral: 2.0mm

Inspect the front wheel hub.

Replace if cracks or damage.

Inspect the front brake drum.

Measure the front brake drum I.D.

Service limits: 111mm

FRONT WHEEL BEARING

Remove the side collar.

Side Colla

r



Keep oil or grease off the

b

rake dru

m

.

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-6

MX’er SYSTEM

Remove the dust seal.

Turn the inner race of each bearing with

your finger to see if they turn smoothly and

quietly. Also check if the outer race fits

tightly in the hub.

BEARING REPLACEMENT

Remove the front wheel bearings and

distance collar.

Replace the bearings if the races do not turn

smoothly, quietly, or if they fit loosely in

the hub.

Apply grease to a new dust seal lip and

install the dust seal.

Pack all bearing cavities with grease.

Drive in the left bearing.

Install the distance collar.

Drive in the right bearing.

Oil seal and bearing install E014

Dust Seal

Wheel Bearin

g

Dust Seal Side Colla

r

Colla

r

Driver Handle

Outer Driver

• Do not allow the bearings to tilt while

driving them in.

• Drive in the bearing squarely with the

sealed end facing out.



Special

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-7

MX’er SYSTEM

FRONT BRAKE

FRONT BRAKE LINING INSPECTION

Measure the front brake lining thickness.

Service limit: 2.0mm replace if below

REMOVAL

Inspect the shoe springs, O-rings, camshaft

lever and wear indicator.

Replace if damage.

Inspect the brake shoe plate.

Replace if cracks or damage.

Inspect the brake shoe pivot pin.

Replace if wear or damage.

Inspect the camshaft hole and camshaft.

Replace if scratches or excessive wear.

INSTALLATION

Reverse the “REMOVAL” procedures.

Tighten the bolt for camshaft lever.

Torque: 1.82.5kgf-m

Brake Linin

g

Keep oil or grease off the brake linings.



Camshaft leve

r

Wear Indicato

r

Brake Plate

Apply the grease onto the o-ring, oil seal

lips, pivot pin of brake shoe and

camshaft.



• Install the camshaft to the brake shoe

plate with the slot of the camshaft

placing at bass line of the wear

indicator scale.

• Align the projection with the slot of the

camshaft when installing the wear

indicator to the camshaft.

• Align the cut-out of the camshaft lever

with the slot of the camshaft when

installing the camshaft lever to the

camshaft.



O-rin

g

s

S

p

rin

g

s

Oil Seal

Brake shoe

p

ivot

p

in

Camshaf

t

Camshaft Hole

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-8

MX’er SYSTEM

Install the brake shoe plate.

Apply the grease onto the bearings and oil

seal lips of the wheel hub.

Install wheel hub, plate washer and tight the

nut (wheel hub).

Torque: 6.08.0kgf-m

Install cotter pins.

Install the front wheel and tighten the nuts

(wheel).

Torque: 6.08.0kgf-m

Adjust the front brake cable free play.

Refer to the “FRONT BRAKE

ADJUSTMENT” section in the

CHAPTER 3.

Brake cable free play: 1020mm at lever

pivot.

Make sure that the boss on the knuckle

correctly engages with the locating slot

on the brake shoe plate.



Boss

Locatin

g

Slo

t

Do not loosen the axle nut after torque

tightening. If the axle nut groove id not

aligned with the cotter pin hole, align

groove with the hole by tightening ut on

the axle nut.



Always use a new cotter pin.



Tapered wheel nuts are used for front

wheels.

Install the nuts with its tapered side

towards the wheel.



12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-9

MX’er SYSTEM

FRONT SUSPENSION

REMOVAL

Elevate the front wheels by placing a

suitable stand under the frame.

Remove the front wheel, wheel hub, brake

shoe plate.

Remove the upper and lower bolt, then

remove the shock absorber.

Remove the cotter pin and nut, then remove

tie-rod from steering knuckle.

Remove cotter pin, nut, washer and bolt,

then remove the steering knuckle, covers,

collar and bush from the front arm.

Upper Bol

t

Lower Bol

t

Support the machine securely so there is

no dan

g

er of it fallin

g

over.



Tie-rod Nu

t

Cotter pinSteering Knuckle

Front ar

m

Cotter pin Nu

t

Steering Knuckle

Bol

t

Washe

r

Cove

r

Bush Colla

r

Bush Cove

r

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-10

MX’er SYSTEM

INSPECTION

Check the front arm brackets of the frame.

If bent, cracked or damaged, repair or

replace the frame.

Check the tightening torque of the front

arms securing nuts.

Torque: 4.05.0kgf-m

Check the front arm side play by moving it

from side to side.

If side play noticeable, replace the inner

collar, bushings and thrust covers as a set.

Check the front arm vertical movement by

moving it up and down.

If vertical movement is tight, binding or

rough, replace the inner collar, bushings and

thrust covers as a set.

Remove the two nut and two bolt attaching

the front arm, then remove the front arm.

INSPECTION

Inspect the shock absorber rod.

Replace the shock absorber assembly if

bends or damage.

Inspect the shock absorber.

Replace the shock absorber assembly if oil

leakes.

Inspect the spring of the shock absorber by

move the spring up and down.

Replace the shock absorber assembly if

fatigue.

Nuts

Bush

Front Ar

m

Bol

t

Bush

Bol

t

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-11

MX’er SYSTEM

Inspect the steering knuckle.

Replace if cracks, pitting or damage.

.

Inspect the front arm.

Replace if cracks, bends or damage.

Inspect bushes.

Replace if wear or damage.

INSTALLATION

Reverse the “REMOVAL” procedures.

Install the front arm nut onto the frame and

tighten the nuts.

Torque: 4.05.0kgf-m

Do not attempt to straighten a bent arm,

this ma

y

dan

g

erousl

y

weaken the arm.



Bushes

Apply the grease onto the bushes, collars

and covers.



12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-12

MX’er SYSTEM

Apply the grease onto the bush, collars and

covers, then install the steering knuckle

onto the front arm and tighten the nut.

Torque: 4.05.0kgf-m

Install the cotter pin and band ends of cotter

pin.

Install the tie-rod onto the steering knuckle

and tighten the nut.

Torque: 4.05.0kgf-m

Install the cotter pin and band ends of cotter

pin.

Install the shock absorber and tighten the

upper and lower bolts.

Torque: 3.54.5kgf-m

Install the brake shoe plate, wheel hub and

front wheel.

Refer to the “FRONT WHEEL

INSTALLATION” section.

Bleed Valve



Always use a new cotter pin.



12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-13

MX’er SYSTEM

STEERING SYSTEM

REMOVAL

Remove the following parts:

Seat, Front cover, Center cover and Front

fender

Refer to the “FENDERS” section in the

CHAPTER 2

Disconnect the main switch lead.

Remove the handlebar cover with main

switch.

Disconnect the front brake cables from the

brake lever, rear brake cable from the brake

lever and brake switch from the bracket of the

brake lever.

Remove the two screws to remove the cover

of the throttle housing.

Disconnect the throttle cable from the lever.

Handlebar Cove

r

Main Switch Lead

Brake Switch

Hook

Front Brake Cables Rear Brake Cable

Disconnect the brake switch from the

bracket of the brake lever while pushing

the hook of the brake switch with a

driver.



Cove

r

Screws Throttle Housing

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-14

MX’er SYSTEM

Remove the two screws and remove the

handlebar switch.

Remove the two bolts and remove headlight

unit.

Remove the four handlebar holder bolts and

remove the handlebar.

Remove the cotter pins and nuts attaching

the tie-rods, then remove tie-rods.

Remove the cotter pin and nut attaching the

steering column, then remove steering

column and collar.

Screws Handlebar Switch

Headlight Uni

t

Bolts

Bolts Handleba

r

Cotter Pin

Nu

t

Nu

t

Tie-rod

Cotter Pin Nu

t

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-15

MX’er SYSTEM

Remove the two bolts to remove the cable

holder, steering bracket, collars and steering

column.

INSPECTION

Inspect the handlebar.

Replace if cracks, bends or damage.

Inspect the steering column.

Replace if bends or damage.

Inspect the steering brackets and oil seal.

Replace if wear or damage.

Bolts

Colla

r

Steering Column

Cable Holde

r

Do not attempt to straighten a bent shaft,

this may dangerously weaken the shaft.



Steering Bracke

t

Steering Brackets

Oil Seal

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-16

MX’er SYSTEM

Inspect the tie-rod.

Replace if bend or damage.

Check the tie-rod end movement.

Replace if the tie-rod end exists free play or

turns roughly.

Check the tapered surface of the tie-rod end.

Replace if pitting, wear or damage.

Adjust the tie-rod length.

Adjustment steps:

(The following procedures are done on both

tie-rods, right and left.)

Loosen the lock nuts.

Adjust the tie-rod length by tuning both

tie-rod ends.

Tie rod length: 266.5mm

Set the rod-end (steering column side) in an

angle where the indentation surface of the

tie-rod is parallel to the rod-end shaft, and

then tighten the lock nut.

Torque: 2.53.5kgf-m

Set the other rod-end (knuckle arm side) in

an angle as shown (right-hand tie-rod and

left-had tie-rod), and then tighten the lock

nut.

Rod-end (tie rod) angle: 180º

Torque: 2.53.5kgf-m

Lock Nu

t

Indentation Surface Lock Nu

t

To Steering Column

After making adjustment on both tie rods

be sure to mark them R and L for

identification.



To Knuckle Ar

m

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-17

MX’er SYSTEM

Inspect the collar, duty seal, snap ring and

bearing.

Replace if wear or damage.

INSTALLATION

Reverse the “REMOVAL” procedures.

Assembly the steering column and tighten

the two bolts.

Torque: 1.82.5kgf-m

Band the lock washer tabs.

The threads on both rod-end must be of

the same len

g

th.



Apply the grease onto the collar, duty

seal, and bearing.



Colla

r

Snap Ring

Bearing

Dust Seal

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-18

MX’er SYSTEM

Install the steering column and collar, then

tighten the nut.

Torque: 6.08.0kgf-m

Install the cotter pin and band ends of cotter

pin.

Install the tie rods and tighten the nut.

Torque: 4.05.0kgf-m

Install the cotter pin and band ends of cotter

pin.

Install handlebar and handlebar holder, then

tighten the four bolts.

Torque: 1.82.5kgf-m

Be sure that the ro

d

-end on the

indentation surface side is connected to

the steering column.



Always use a new cotter pin.



Always use a new cotter pin.



Indentation Surface

Bolts Headlight Uni

t

Bolts Handleba

r

Cotter Pin

Nu

t

Nu

t

Tie-rod

Cotter Pin Nu

t

12. FRONT WHEEL/FRONT BRAKE/FRONT

SUSPENSION/STEERING SYSTEM

12-19

MX’er SYSTEM

Apply the grease onto the end of the throttle

cable and end of the brake cable.

Refer to the “TOE-IN ADJUSTMENT”

section in the CHAPTER 3 to adjust toe-in.

Refer to the “FRONT BRAKE

ADJUSTMENT” section in the CHAPTER

3 to adjust front brake.

Refer to the “REAR BRAKE

ADJUSTMENT” section in the CHAPTER

3 to adjust rear brake.

• Be sure the upper handlebar holder

mark face to front.

• Fist tighten the bolts on the front side

of the handlebar holder, and then

tighten the bolts on the rear side.



15. IGNITION SYSTEM

15-0

MX’er SYSTEM

15

__________________________________________________________________________________

____________________________________________________________________

15

____________________________________________________________________

IGNITION SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 15- 2

TROUBLESHOOTING----------------------------------------------------- 15- 3

CDI UNIT INSPECTION--------------------------------------------------- 15- 4

IGNITION COIL------------------------------------------------------------- 15- 6

PULSER COIL--------------------------------------------------------------- 15- 7

15. IGNITION SYSTEM

15-1

MX’er SYSTEM

Ignition Switch

CDI Uni

t

/Change Gear Control.

l

A.C. Generato

r

/

Pulser Coil

Spark Plug

Ignition Coil

IGNITION CIRCUIT

PULSER COIL

15. IGNITION SYSTEM

15-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• Check the ignition system according to the sequence specified in the Troubleshooting.

• The ignition system adopts CDI unit , change gear control and the ignition timing cannot be

adjusted.

• If the timing is incorrect, inspect the CDI unit, A.C. generator, change gear control and replace

any faulty parts. Inspect the CDI unit with a CDI tester

• Loose connector and poor wire connection are the main causes of faulty ignition system.

Check each connector before operation.

• Use of spark plug with improper heat range is the main cause of poor engine performance.

• The inspections in this section are focused on maximum voltage. The inspection of ignition coil

resistance is also described in this section.

• Inspect the ignition switch according to the continuity table specified in page 17-5.

• Inspect the spark plug referring to Section 3.

SPECIFICATIONS

Item Standard

Standard type CR8E

Spark plug Hot type

Cold type

Spark plug gap 0.60.7mm

Ignition timing “F” mark

Full advance 15ºBTDC/1,700±100rpm

Primary coil 0.20.3Ω

Ignition coil resistance (20) Secondary with plug cap 3.24.8KΩ

coil plug cap 4.25.2KΩ

Pulser coil resistance (20) 5060Ω

Exciter coil resistance (20) 100120Ω

Ignition coil primary side max. voltage 12V min.

Pulser coil max. voltage 2.1V min.

TESTING INSTRUMENT

Kowa Electric Tester

or commercially available electric tester with resistance over 10MΩ/CDV

15. IGNITION SYSTEM

15-3

MX’er SYSTEM

TROUBLESHOOTING

High voltage too low No high voltage

• Weak battery or low engine speed • Faulty ignition switch

• Loose ignition system connection • Faulty CDI unit

• Faulty CDI unit • Poorly connected or broken CDI ground wire

• Faulty ignition coil •Dead battery or faulty regulator/rectifier

• Faulty pulser coil • Faulty ignition coil connector

Normal high voltage but no spark at plug • Faulty pulser coil

• Faulty spark plug

• Electric leakage in ignition secondary circuit

• Faulty ignition coil

Good spark at plug but engine won‘t start

• Faulty CDI or incorrect ignition timing

• Faulty change gear control unit

• Improperly tightened A.C. generator flywheel

CDI UNIT INSPECTION

Remove the seat.

Disconnect the CDI coupler and remove the

15. IGNITION SYSTEM

15-4

MX’er SYSTEM

CDI unit.

Measure the resistance between the

terminals using the electric tester.

.

Testing Range

Use the xKΩ range for the Sanwa Tester.

Use the xKΩ range for the Kowa Tester.

Note: The readings in this table are taken

with a Sanwa Tester.

• Due to the semiconductor in circuit, it is

necessary to use a specified tester for

accurate testing. Use of an improper

tester in an improper range may give

false readings.

• Use a Sanwa Electric Tester or Kowa

Electric Tester.

• In this table, “Needle swings then

returns” indicates that there is a charging

current applied to a condenser. The needle

will then remain at “∞” unless the

condenser is discharged.



Unit: KΩ

Test the CDI unit using the CDI tester.

Black

/

White

Blue/Yellow

CDI Uni

t

Black/Red

Black/Yellow

Green/Red

Green/White

Probe⊕

(-)Probe

Black/

White Black/

Red Blue/

White Green Green/

White Black/

Yellow

Black/

White ∞ ∞ ∞ ∞ ∞

Black/

Red 3-6K ∞ ∞ ∞ ∞

Blue/

White 35-42K 18-22K 8-10K 8-10K ∞

Green 15-18K 4.5-5.5K 7-9K There is

continuity ∞

Green/

White 15-18K 4.5-5.5K 8-9K There is

continuity ∞

Black/ ∞ ∞

∞

Needle

Swings then Needle

Swings then

Change Gear Control



Operate the CDI tester by following the

manufacturer‘s instructions.

15. IGNITION SYSTEM

15-5

MX’er SYSTEM

Connect the special connector to the CDI

coupler and CDI tester.

Switch Range Good CDI Faulty CDI

1. OFF

2. P

3. EXT

4. ON1

5. ON2

No spark

Good spark

⎯⎯

Good spark

No spark

If the CDI unit is faulty, replace it with a

new one.

Remove the seat.

Disconnect the change gear control coupler

and remove the change gear control unit.

Measure the resistance between the

terminals using the electric tester.

Testing Range

Use the xKΩ range for the Sanwa Tester.

Use the xKΩ range for the Kowa Tester.

Note: The readings in this table are taken

with a Sanwa Tester.

CDI Teste

r

Ignition Coil

Spark

Window

CDI Uni

t

Spark Plug

Unit:

KΩ

IGNITION COIL INSPECTION

CONTINUITY TEST

Probe⊕

(-)Probe

Black Green Green/

Yellow Green/

Pink Light Green/

Red Blue/

Yellow Yellow/

Brown

Black

5-50K 5-50K 5-50K 5-50K 5-50K 5-50K

Green ∞

5-50K 5-50K 5-50K 5-50K 0

Green/

Yellow ∞ 5-50K 10-50K 10-50K 10-50K 5-50K

Green/

Pink ∞ ∞ ∞ 0 ∞ ∞

Light Green/

Red ∞ ∞ ∞ 0 ∞ ∞

Blue/

Yellow ∞ 50-200K 50-200K 50-200K 50-200K

Yellow/

B

∞ 0 5-50

K

5-50

K

5-50

K

5-50

K

Blue/Yellow Yellow/Brown Light Green/Red

Black Green /YellowGreen

Green

/

Pink

15. IGNITION SYSTEM

15-6

MX’er SYSTEM

Remove the front cover.

Remove the spark plug cap.

Disconnect the ignition coil wires.

Measure the resistance between the ignition

coil primary coil terminals.

Resistance: 0.20.3Ω/20

Remove the spark plug cap and measure the

secondary coil resistance between the spark

plug wire and the primary coil terminal.

Resistance: 3.24.8KΩ/20

Measure the spark plug cap resistance.

Remove the spark plug cap and measure the

spark plug resistance.

Resistance: 4.25.2KΩ/20

PERFORMANCE TEST

Test the performance with a CDI tester.

If the spark is weak, inspect the spark plug

and CDI unit. If both of them are normal,

replace the ignition coil with a new one.

This test is to inspect the continuity of

ignition coil.



This test is for reference only. Accurate

test should be performed with a CDI

tester.



Measure the resistance in the XKΩrange

of the electric tester.



• Operate the CDI tester by following

the manufacturer‘s instructions.

• Use the special connector to connect

the CDI unit.



PULSER COIL

I

g

nition Coil

INSPECTION

15. IGNITION SYSTEM

15-7

MX’er SYSTEM

Remove the front cover.

Disconnect the pulser coil wire coupler and

measure the resistance between the blue/

yellow and green/white wire terminals.

Resistance: 5060Ω

EXCITER COIL

INSPECTION

Disconnect the exciter coil wire coupler and

measure the resistance between the

black/red wire terminal and ground.

Resistance: 100120Ω

16. STARTING SYSTEM

16-0

MX’er SYSTEM

16

__________________________________________________________________________________

____________________________________________________________________

16

____________________________________________________________________

STARTING SYSTEM

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 16- 2

TROUBLESHOOTING----------------------------------------------------- 16- 2

STARTER MOTOR--------------------------------------------------------- 16- 3

STARTER RELAY---------------------------------------------------------- 16- 5

16. STARTING SYSTEM

16-1

MX’er SYSTEM

Ignition

Sith

Starter Moto

r

Starter Button

Fuse/Battery

/

Starter Relay

Stop Switches

STARTING CIRCUIT

16. STARTING SYSTEM

16-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• The removal of starter motor can be accomplished with the engine installed.

• For the starter clutch removal, refer to Section 4.

SPECIFICATIONS

Item Standard (mm) Service Limit (mm)

Starter motor brush length 12.5 8.5

TROUBLESHOOTING

Starter motor won‘t turn Lack of power

• Fuse burned out • Weak battery

• Weak battery • Loose wire or connection

• Faulty ignition switch • Foreign matter stuck in starter motor

• Faulty starter clutch or gear

• Faulty front or rear stop switch

• Faulty starter relay Starter motor rotates but engine does

• Poorly connected, broken or shorted wire not start

• Faulty starter motor • Faulty starter clutch

• Starter motor rotates reversely

• Weak battery

16. STARTING SYSTEM

16-3

MX’er SYSTEM

STARTER MOTOR

REMOVAL

Remove the two starter motor mounting

bolts and the motor.

Remove the waterproof rubber jacket and

disconnect the starter motor cable

connector.

DISASSEMBLY

Remove the two starter motor case screws,

front cover, motor case and other parts.

INSPECTION

Inspect the removed parts for wear, damage

or discoloration and replace if necessary.

Clean the commutator if there is metal

powder between the segments.

Check for continuity between pairs of the

commutator segments and there should be

continuity.

Also, make a continuity check between

individual commutator segments and the

armature shaft. There should be no

continuity.

Front Cove

r

Starter Motor Cable

Bolts

Commutato

r

Before removing the starter motor, turn

the ignition switch OFF and remove the

battery ground. Then, turn on the

ignition switch and push the starter

button to see if the starter motor operates

properly.



Case Screws Motor Case

16. STARTING SYSTEM

16-4

MX’er SYSTEM

STARTER MOTOR CASE

CONTINUITY CHECK

Check to confirm that there is no continuity

between the starter motor wire terminal and

the motor front cover.

Also check for the continuity between the

wire terminal and each brush.

Replace if necessary.

Measure the length of the brushes.

Service Limit: 8.5mm replace if below

Check for continuity between the brushes. If

there is continuity, replace with new ones.

Check if the needle bearing in the front

cover turns freely and has no excessive

play.

Replace if necessary.

Check the dust seal for wear or damage.

Wire Terminal

Bearin

g

Dust Seal

16. STARTING SYSTEM

16-5

MX’er SYSTEM

ASSEMBLY

Apply grease to the dust seal in the front

cover.

Install the brushes onto the brush holders.

Apply a thin coat of grease to the two ends

of the armature shaft.

Insert the commutator into the front cover.

Install a new O-ring to the front cover.

Install the starter motor case, aligning the

tab on the motor case with the groove on the

front cover.

Tighten the starter motor case screws.

STARTER RELAY

INSPECTION

Remove the seat.

Turn the ignition switch ON and the starter

relay is normal if you hear a click when the

starter button is depressed.

If there is no click sound:

• Inspect the starter relay voltage

• Inspect the starter relay ground circuit

• Check for continuity between the starter

relay yellow/red and green/red wire

terminals

STARTER RELAY VOLTAGE

INSPECTION

Connect a 12V battery across the starter

relay yellow/red and green/red wire

terminals.

Connect an electric tester between the

starter relay large terminals and check for

continuity between the two terminals.

The relay is normal if there is continuity.

Replace the starter relay with a new one if

there is no continuity.

Commutato

r

Front Cove

r

Groove

Motor Case

O-rin

g

Tab

Starter Rela

y

• Be careful not to damage the brush and

armature shaft mating surfaces.

• When installing the commutator, the

armature shaft should not damage the

dust seal lip.



When assembling the front cover and

motor case, slightly press down the

armature shaft to assemble them.



16. STARTING SYSTEM

16-6

MX’er SYSTEM

STARTER MOTOR INSTALLATION

Connect the starter motor cable connector

and properly install the waterproof rubber

jacket.

Check the O-ring for wear or damage and

replace if necessary.

Apply grease to the O-ring and install the

starter motor.

Tighten the two mounting bolts.

O-rin

g

The starter mo

be installed properly.

tor cable connector must



17. LIGHTS/ SWITCHES

17-0

MX’er SYSTEM

17

__________________________________________________________________________________

____________________________________________________________________

17

LIGHTS/SWITCHES

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 17- 2

TROUBLESHOOTING----------------------------------------------------- 17- 2

HEADLIGHT ---------------------------------------------------------------- 17- 3

INSTRUMENTS/STOP LIGHT/TAILLIGHT -------------------------- 17- 4

IGNITION SWITCH -------------------------------------------------------- 17- 5

STOP SWITCH -------------------------------------------------------------- 17- 5

STARTER BUTTON-------------------------------------------------------- 17- 6

HEADLIGHT SWITCH ---------------------------------------------------- 17- 6

ENGINE STOP SWITCH -------------------------------------------------- 17- 6

17. LIGHTS/ SWITCHES

17-1

MX’er SYSTEM

ELECTRICAL EQUIPMENT LAYOUT

Stop Switches

Ignition Switch

Headlight Switch

/

Starter Button

Headlight

Taillight/Stop Light

17. LIGHTS/ SWITCHES

17-2

MX’er SYSTEM

SERVICE INFORMATION

GENERAL INSTRUCTIONS

• An electric tester is needed to measure or test the electric equipment.

• Be sure to use fuses and bulbs of the same specifications to avoid damage of electrical

equipment.

• After installation of each switch, a continuity check must be performed. A continuity check can

usually be made without removing the part from the motorcycle.

TROUBLESHOOTING

Lights do not come on Engine starts but stalls during idling

when ignition switch is “ON” • Clogged carburetor

• Faulty ignition switch

• Fuse burned out

• Weak battery

• Burned bulb

• Faulty switch

• Poorly connected, broken or shorted wire

17. LIGHTS/ SWITCHES

17-3

MX’er SYSTEM

HEADLIGHT

BULB REPLACEMENT

Disconnect the cover of the ignition switch

and remove the two headlight attaching

bolts.

Remove the headlight and disconnect the

headlight wire coupler.

Remove the two headlight case attaching

screws and disconnect the headlight.

Check the bulb for damage and replace with

a new one if necessary.

Disconnect the headlight wire coupler.

Remove the rubber boot.

Push and disconnect the spring from the

headlight cover.

Screws

Bolts

Cove

r

Screws

Headli

g

ht Wire Cou

p

le

r

Rubber Boo

t

17. LIGHTS/ SWITCHES

17-4

MX’er SYSTEM

Remove the headlight bulb

INSTALLATION

Install the headlight in the reverse order of

removal.

INSTRUMENTS

REMOVAL

Remove the two headlight attaching bolts.

Remove the headlight and disconnect the

headlight wire coupler.

Remove the two headlight case attaching

screws and disconnect the headlight.

Remove the light shell, rubber boot and

bulb socket.

Check the bulb for damage and replace with

a new one if necessary.

INSTALLATION

The installation sequence is the reverse of

removal.

STOP LIGHT/TAILLIGHT

Remove the two taillight shell screws and

the shell.

Headli

g

ht Bulb

Li

g

ht Shell

Taillight Shell Screws

After installation, adjust the headlight

beam.



Bulb Socke

t

Rubber Boo

t

Taillight Shell

17. LIGHTS/ SWITCHES

17-5

MX’er SYSTEM

Remove the bulb and check the bulb for

damage. Replace with a new one if

necessary.

IGNITION SWITCH

Check for continuity between the wires

indicated below.

Color

Position Black Red

Black/

White Green

OFF ○ ○

ON ○ ○

STOP SWITCH

Disconnect the front stop switch wire

coupler.

Check for continuity between the front stop

switch wires.

Brake lever applied: There is continuity.

Brake lever released: There is no continuity.

Bul

b

17. LIGHTS/ SWITCHES

17-6

MX’er SYSTEM

STARTER BUTTON

Remove the center cover.

Disconnect the starter button yellow/brown

and yellow/red wires.

Check for continuity between the black and

yellow/red wires.

Color

Position Yellow/Brown Yellow/Red

FREE

PUSH ○ ○

HEADLIGHT SWITCH

Remove the center cover.

Disconnect the headlight switch wire

coupler. Check for continuity between the

headlight switch wires.

Color

Position Black Brown White Blue



○ ○ ○

ENGINE STOP SWITCH

Remove the center cover.

Disconnect the headlight switch wire

coupler. Check for continuity between the

headlight switch wires.

Color

Position Green/Red Green

○ ○

Yellow

/

Brown Yellow

/

Red

Starter Button

Black BrownWhite

Blue

Headlight Switch

Green/Red

Green

Engine Stop Switch

17. LIGHTS/ SWITCHES

17-7

MX’er SYSTEM

18. ONLY ATV ON ROAD AVAILABLE

18-0

MX’er SYSTEM

18

__________________________________________________________________________________

____________________________________________________________________

ONLY ATV ON ROAD AVAILABLE

____________________________________________________________________

18

WARING DIAGRAM ------------------------------------------------------ 18- 1

BRAKE PEDAL ADJUSTMENT----------------------------------------- 18- 2

INSTRUMENT -------------------------------------------------------------- 18- 3

INDICATOR LIGHT-------------------------------------------------------- 18- 3

HAZARD SWITCH --------------------------------------------------------- 18- 4

HORN ------------------------------------------------------------------------- 18- 4

18. ONLY ATV ON ROAD AVAILABLE

18-1

MX’er SYSTEM

WIRING DIAGRAM

18. ONLY ATV ON ROAD AVAILABLE

18-2

MX’er SYSTEM

BRAKE PEDAL ADJUSTMENT

The brake pedal free play should be

adjusted

to 10~20 mm (0.4~0.8 in) at the brake pedal

pivot. If the free play is incorrect, adjust as

Follows:

Keep front brake lever free play at 10~20

mm (0.4~0.8 in). (Refer to page 3-9)

Loosen the lock nut.

Turn the adjusting bolt until the front

lower brake cable is tensed.

Apply the front brake lever and check front

bake cam lever to make sure that the brake

does not drag after adjusting.

Tighten the lock nut.

Turn the adjusting nut on the brake cam

lever to decrease play or increase play.

Turn the adjusting nut until specified free

Play is obtained.

Brake Pedal

10~20mm

Front lower brake cable Lock Nut

Brake Cam Lever Adjusting Bolt

Adjusting Nut

18. ONLY ATV ON ROAD AVAILABLE

18-3

MX’er SYSTEM

INSTRUMENT

REMOVAL

Remove the two instrument attaching

screws.

Disconnect the instrument.

Remove battery cover on instrument back to

replace battery.

SENSOR WHEEL

If the sensor is lost or wore, the speed will

be not calculated on the instrument.

INDICATOR LIGHT

REMOVAL

Remove the screw and disconnect the cover

of the ignition switch.

Screws

Battery Cover



After replace battery, the instrument will

be reset. (Refer to owner’s manual)

Speed Wheel

Screw

18. ONLY ATV ON ROAD AVAILABLE

18-4

MX’er SYSTEM

Remove the bulb socket and bulb.

Check the bulb for damage and replace with

a new one if necessary.

INSTALLATION

The installation sequence is the reverse of

removal.

HAZARD SWITCH

Check for continuity between the wires

indicated below.

Color

Position Yellow

/Black Black

○ ○

●

HORN

REMOVAL

Disconnect the horn switch wire.

Remove the bolt and remove horn.

INSTALLATION

The installation sequence is the reverse of

removal.

Bulb Socket

Bulb

Hazard Switch

Bolt Horn Switch wire

18. ONLY ATV ON ROAD AVAILABLE

18-5

MX’er SYSTEM

Kymco MXER 125 150 Service Manual

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