Kymco MXER 125 150 Service Manual

User Manual: Kymco MXER 125 - 150 Service Manual

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PREFACE
TABLE OF CONTENTS
This Service Manual describes the
technical features and servicing
procedures for the KYMCO MX’er
125/150.

CYLINDER/PISTON

1
2
3
4
5
6
7
8

DRIVE AND DRIVEN PULLEYS

FINAL REDUCTION/TRANSMISSION
SYSTEM

CRANKCASE/CRANKSHAFT/
BALANCE SHAFT

FRONT WHEEL/FRONT BRAKE/
FRONT SUSPENSION/STEERING
SYSTEM

REAR WHEEL /SWING
ARM/HYDRAULIC BRAKE

BATTERY/CHARGING SYSTEM/A.C.
GENERATOR

IGNITION SYSTEM

15
16
17
18

GENERAL INFORMATION
FRAME COVERS/EXHAUST MUFFLER
INSPECTION/ADJUSTMENT
LUBRICATION SYSTEM
FUEL SYSTEM
ENGINE

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.

Most sections start with an assembly or
system illustration and troubleshooting
for the section. The subsequent pages
give detailed procedures for the section.
The information and contents included
in this manual may be different from
the motorcycle in case specifications
are changed.

KWANG YANG MOTOR CO., LTD.
OVERSEAS SALES DEPARTMENT
OVERSEAS SERVICE SECTION

ELECTRICAL
EQUIPMENT

Sections 4 through 17 give instructions
for disassembly, assembly and
inspection of engine, chassis frame and
electrical equipment.

CHASSIS

Section 3 describes the inspection/
adjustment procedures, safety rules and
service information for each part,
starting from periodic maintenance.

ENGINE REMOVAL/INSTALLATION
CYLINDER HEAD/VALVES

STARTING SYSTEM
LIGHTS/SWITCHES
ONLY ATV ON ROAD AVAILABLE

1. GENERAL INFORMATION

MX’er SYSTEM

__________________________________________________________________________________

____________________________________________________________________

GENERAL INFORMATION
____________________________________________________________________

SERIAL NUMBER---------------------------------------------------------SPECIFICATIONS ---------------------------------------------------------SERVICE PRECAUTIONS -----------------------------------------------TORQUE VALUES --------------------------------------------------------SPECIAL TOOLS ----------------------------------------------------------LUBRICATION POINTS -------------------------------------------------CABLE & HARNESS ROUTING ---------------------------------------WIRING DIAGRAM-------------------------------------------------------TROUBLESHOOTING-----------------------------------------------------

1- 1
1- 2
1- 4
1-12
1-14
1-15
1-18
1-22
1-23

1-0

1. GENERAL INFORMATION
SERIAL NUMBER

Location of Frame Serial Number

Location of Engine Serial Number

1-1

MX’er SYSTEM

1. GENERAL INFORMATION

MX’er SYSTEM
Cooling Type

Forced air cooling

SPECIFICATIONS

Carburetor

Ignition System

Spark plug

Sponge
8.1 liters
PD
14.8mm
φ25
PISTON
CDI
15°BTDC/1700rpm
Non-contact point type
NGK
CR8E

Spark plug gap
Battery Capacity
Clutch Type

0.6 0.7mm
12V8AH
CVT

Transmis- Reduction
sion Gear Gear

Helical gear

Type
Operation
Type

Automatic centrifugal
type
Chain drive

2.8-0.95
Reduction 1st
ratio
7.226
2nd
26.902
Counter gear ratio
Front Caster angle
Axle Trail length
0.2
Tire pressure Front
(kg/cm²)
Rear
0.25
Turning
Left
44°
angle
Right
44°
Rear Disk brake Drum brake
Brake system
type
Front
Drum brake
Swing
Front
Suspension
type
Rear
Swing arm
Front
Swing
Shock
type
Swing arm
Rear
Frame type
SP pipe

Damping
Device

11/7500
1.1/5500
5.5° BTDC
27.5° ABDC
36° BBDC
4° ATDC
0.06
0.06
1700rpm
Forced pressure &
wet sump
Inner/outer rotor type
Full-flow filtration
1.0 liter

Air cleaner type & No
Fuel capacity
Type
Float lever
Venturi dia.(mm)
Throttle type
Type
Ignition timing
Contact breaker

Moving Device

Oil pump type
Oil filter type
Oil capacity
Oil exchanging
capacity

16.0

Power Drive System

Lubrication
System

Lubrication type

Gasoline, 4-stroke
Single cylinder
Semi-sphere
O.H.C., chain drive
62 x 49.5
9.7:1

Electrical Equipment

Engine

Type
Cylinder arrangement
Combustion chamber type
Valve arrangement
Bore x stroke (mm)
Compression ratio
Compression pressure
(kg/cm²)
Max. output (ps/rpm)
Max. torque (kg m/rpm)
Intake
Open
(1mm)
Close
Port
timing Exhaust Open
(1mm)
Close
Valve clearance Intake
Exhaust
(cold) (mm)
Idle speed (rpm)

Fuel System

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
Tires
Rear wheel
22*10-8
Ground clearance (mm)
130
Breaking distance
20.6 below
Perform(m)(ANSI)
ance
Min. turning radius (m)
3
Starting motor
Starting system

0.9 liter

1-2

1. GENERAL INFORMATION

MX’er SYSTEM

SPECIFICATIONS
Air cleaner type & No
Fuel capacity
Type
Piston dia. (mm)
Venturi dia.(mm)
Throttle type
Type
Ignition timing
Contact breaker
Carburetor

Ignition System

Electrical Equipment

Sponge
8.1 liters
PD
14.8mm
φ25
PISTON
CDI
15°BTDC/1700rpm
Non-contact point type
NGK

Spark plug

Spark plug gap
Battery Capacity
Clutch Type
Transmis- Reduction
sion Gear Gear

Power Drive System

Type
Operation
Type

CR8E
0.6 0.7mm
12V8AH
CVT
Helical gear

Automatic centrifugal
type
Chain drive

Damping
Device

Lubrication
System

1-3

Fuel System

Engine

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
Tires
Rear wheel
22*10-8
Ground clearance (mm)
130
Breaking distance
20.6 below
Perform(m)(ANSI)
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
14.0
(kg/cm²)
Max. output (ps/rpm)
9.8/7500
Max. torque (kg m/rpm)
0.98/5500
Intake
Open
5.5° BTDC
Close
27.5° ABDC
Port (1mm)
Timin Exhaust Open
36° BBDC
g
(1mm)
Close
4° ATDC
Valve clearance Intake
0.06
Exhaust
0.06
(cold) (mm)
Idle speed (rpm)
1700rpm
Forced
pressure &
Lubrication type
wet sump
Oil pump type
Inner/outer rotor type
Oil filter type
Full-flow filtration
Oil capacity
1.0 liter
Oil exchanging
0.9 liter
capacity
Cooling Type
Forced air cooling

1. GENERAL INFORMATION

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.

1-4

1. GENERAL INFORMATION
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.

1-5

MX’er SYSTEM

1. GENERAL INFORMATION
If the fuse is burned out, find the cause
and repair it. Replace it with a new one
according to the specified capacity.

MX’er SYSTEM

Confirm
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.

1-6

1. GENERAL INFORMATION
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.

1-7

MX’er SYSTEM

Snapping!

1. GENERAL INFORMATION

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.

No Contact !

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.

1-8

1. GENERAL INFORMATION
Route harnesses so they are neither
pulled tight nor have excessive slack.

MX’er SYSTEM

Do not pull
too tight!

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.

1-9

Do not press
or squeeze
the wire.

1. GENERAL INFORMATION

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.

Do you understand
the instrument?
Is the instrument set
correctly?

Be careful not to drop any parts.

When rust is found on a terminal, remove
the rust with sand paper or equivalent
before connecting.

Remove Rust !

1-10

1. GENERAL INFORMATION
Symbols:
The following symbols represent the
servicing methods and cautions included
in this service manual.

Engine Oil

Grease

: Apply engine oil to the
specified points. (Use
designated engine oil for
lubrication.)
: Apply grease for
lubrication.

: Transmission Gear Oil
(90#)
Gear Oil

Special

: Use special tool.

: Caution

: Warning

1-11

MX’er SYSTEM

1. GENERAL INFORMATION

MX’er SYSTEM

TORQUE VALUES
STANDARD TORQUE VALUES
Item
5mm bolt, nut
6mm bolt, nut
8mm bolt, nut
10mm bolt, nut
12mm bolt, nut
14mm bolt, nut

Torque (kgf-m)
0.45 0.6
0.8 1.2
1.8 2.5
3.0 4.0
5.0 6.0
6.0 8.0

Item
4mm screw
5mm screw
6mm screw, SH bolt
6mm flange bolt and nut
8mm flange bolt and nut
10mm flange bolt and nut

Torque (kgf-m)
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
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
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

Q‘ty Thread dia.(mm) Torque (kgf-m)
4
1
1
1
8
4
4
2
1
2
1
9
1
1
3
1
1
1
1
1
1
2
2
2
2
1
4

8
30
14
6
6
6
8
6
8
6
6
6
12
12
8
16
14
8
8
12
6
6
6
6
6
22
5

0.7
1.0
4.5
1.0
1.0
0.7
1.8
1.4
0.8
1.0
0.35
0.8
5.5
5.0
2.4
4.0
5.0
1.1
0.8
2.0
0.8
0.8
0.8
0.8
0.8
5.0
0.8

Remarks

1.1
2.0
5.0
1.2
1.4
1.1
2.2
1.8
1.2
1.4
0.5
1.2
6.5
6.0
3.0
5.0
6.0
2.3
1.2
3.0
1.2
1.2
1.2
1.2
1.2
6.0
1.2

1-12

1. GENERAL INFORMATION
Item
R cover
Head cover
Cap R cover
Guide star change handle
Sprocket drive plate
Carburetor
Check bolt oil

Q‘ty
9
4
1
3
2
2
1

MX’er SYSTEM

Thread dia.(mm) Torque (kgf-m)
6
6
6
6
6
6
10

0.8
0.8
0.8
0.8
1.0
0.8
1.0

Remarks

1.2
1.2
1.2
1.2
1.6
1.2
1.5

FRAME
Item

Q‘ty

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
2
1
2
2
1
4
2
1
1
1
2

1-13

Thread dia.(mm) Torque (kgf-m)
14
10
14
14
10
10
10
14
12
32
10
10
10
8

6.0
4.0
6.0
6.0
3.5
3.5
3.5
6.0
6.0
11.0
3.5
3.5
3.5
3.2

8.0
5.0
8.0
8.0
4.5
4.5
4.5
8.0
8.0
13.0
4.5
4.5
4.5
3.8

Remarks

1. GENERAL INFORMATION

MX’er SYSTEM

SPECIAL TOOLS
Tool Name
Flywheel puller
Lock nut wrench
Valve adjuster
Valve spring compressor
Oil seal and bearing install
Universal holder
Flywheel holder
Clutch spring compressor
Bearing puller
Bearing puller
Bearing puller
Bearing puller
Nut wrench
Float level gauge

Tool No.
E003
E009
E012
E040
E014
E017
E021
E027
E008
E018

Remarks Ref. Page

E020
E031
F010

1-14

1. GENERAL INFORMATION

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

1-15

Gear oil: SAE90#

1. GENERAL INFORMATION

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.
abnormal noise and rise the durability of the motorcycle.

This will avoid

Rear Brake Cable
Front Brake Cable
Throttle Cable

Front Arm Bush

Steering Column Upper

Front Arm Bush
Front Brake
camshaft/Oil
Seal/O-ring
Front Brake
camshaft/Oil
Seal/O-ring

Front Wheel
Oil Seal
Steering Column Lower

Steering knuckle/Thrust
Cover/Bush/Collar

Front Wheel
Oil Seal

Steering knuckle/Thrust
Cover/Bush/Collar

1-16

1. GENERAL INFORMATION

MX’er SYSTEM

Swing arm Thrust
Cover

Rear Brake Cam/
Axle Hub Collar/Oil
Seal/Bearing

Sprocket hub/Rear
Axle Hub Collar/Oil
Seal/Bearing
Driven Sprocket

1-17

1. GENERAL INFORMATION

MX’er SYSTEM

CABLE & HARNESS ROUTING
Rear Brake Cable
Throttle Cable

Handlebar Switch Lead
Front Brake Cable

Right Front Brake Cable

Left Front Brake Cable

1-18

1. GENERAL INFORMATION

Main Switch

MX’er SYSTEM

Breather Hose (CYL
Head Cover)

Inlet Hose

Breather
Hose
(C k

1-19

)

1. GENERAL INFORMATION

MX’er SYSTEM

Breather Hose

Wire Harness
Rectifier/Regulato

Fuse

Outlet Hose

Ignition Coil

1-20

1. GENERAL INFORMATION

MX’er SYSTEM

A.C.G Wire
Connector

Breather Hose (CYL
Head Cover)

Battery Negative
Cable
Positive Cable
Battery

Starter Relay

1-21

Change Gear Control

CDI Unit

Fuse

1. GENERAL INFORMATION

MX’er SYSTEM

WIRING DIAGRAM

1-22

1. GENERAL INFORMATION

MX’er SYSTEM

TROUBLESHOOTING
ENGINE WILL NOT START OR IS HARD TO START
Inspection/Adjustment

Probable Cause

Symptom

Check if fuel reaches
carburetor by loosening
drain screw
Fuel reaches
carburetor

Fuel does not
reach carburetor

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

Weak or no spark

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

Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground
Spark jumps

Test cylinder
compression

Faulty starter clutch
Valve clearance too small
Valve stuck open
Worn cylinder, piston and piston
rings
Leaking cylinder head gasket

Normal
compression

Low or no
compression

Engine does not
fire

Engine fires but
does not start

Air leaking through intake pipe
Leaking intake manifold
Incorrect ignition timing
Incorrectly adjusted air*/ screw

Dry spark plug

Wet spark plug

Flooded carburetor
Clogged air cleaner
Throttle valve excessively open

Start engine by
follow-ing normal
starting procedure

Remove spark plug and
inspect again

1-23

1. GENERAL INFORMATION

MX’er SYSTEM

ENGINE LACKS POWER
Inspection/Adjustment

Probable Cause

Symptom

Start engine and
accelerate lightly for
observation
Engine speed
increases

Engine speed does not
increase sufficiently

Check ignition timing
(using a timing light)

Clogged air cleaner
Restricted fuel flow
Clogged fuel tank cap breather hole
Clogged exhaust muffler
Carburetor fuel level too low
Faulty CDI unit

Correct timing

Incorrect timing

Correct

Incorrect

Normal
compression

Abnormal
compression

Not clogged

Clogged

Plug not fouled or
discolored

Plug fouled or
discolored

Correct and not
contaminated

Incorrect or
contaminated

Faulty pulser coil

Check valve clearance
Improper valve clearance
adjustment
Excessively worn valve seat
(protruded valve stem)

Test cylinder compression
Improper valve and seat contact
Worn cylinder and piston rings
Leaking cylinder head gasket
Improper valve timing

Check carburetor for
clogging
Clean and unclog

Remove spark plug and
inspect
Fouled spark plug
Incorrect heat range plug

Remove oil dipstick and
check oil level and condition
Oil level too high
Oil level too low
Oil not changed

Remove cylinder head oil
pipe bolt and inspect
Valve train lubricated
properly

Valve train not
lubricated properly

Clogged oil line
Faulty oil pump

Check if engine overheats
Engine does not
overheats

Engine overheats

Rapidly accelerate or run
at high speed
Engine does not knock

Engine knocks

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

1-24

1. GENERAL INFORMATION

MX’er SYSTEM

POOR PERFORMANCE (ESPECIALLY AT IDLE AND LOW SPEEDS)

Inspection/Adjustment

Symptom

Probable Cause

Check ignition timing

Correct timing

Incorrect timing

Correctly adjusted

Incorrectly adjusted

Faulty CDI unit
Faulty pulser coil

Check carburetor air
screw adjustment
Mixture too rich (turn screw
out)
Mixture too lean (turn screw in)

Check carburetor gasket
for air leaks

No air leak

Air leaks

Remove spark plug and
install it into spark plug
cap to test spark by
connecting it to engine
ground
Good spark

1-25

Weak or intermittent spark

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

1. GENERAL INFORMATION

MX’er SYSTEM

POOR PERFORMANCE (AT HIGH SPEED)

Inspection/Adjustment

Symptom

Probable Cause

Check ignition timing

Correct timing

Incorrect timing

Correctly adjusted

Incorrectly adjusted

Faulty CDI unit
Faulty pulser coil

Check valve clearance
Improperly adjusted valve
clearance
Worn valve seat

Check fuel pump for
fuel supply

Fuel flows freely

Fuel flow restricted

Empty fuel tank
Clogged fuel tube or filter
Clogged Fuel tank cap breather
hole

Check carburetor jets
for clogging

Not clogged

Clogged

Clean and unclog

Correct

Incorrect

Cam timing gear aligning marks
not aligned

Not weakened

Weak spring

Check valve timing

Check valve spring
tension

Faulty spring

1-26

1. GENERAL INFORMATION

MX’er SYSTEM

POOR CHARGING (BATTERY OVER DISCHARGING OR OVERCHARGING)
Undercharging
Inspection/Adjustment

Symptom

Probable Cause

Start engine and test
limit voltage of battery
terminals
Voltage does not
increase

Dead battery
Faulty battery

Normal

Resistance too high

Faulty A.C. generator coil
Broken yellow wire
Shorted pink and yellow
wires

Normal voltage

No voltage

Broken red wire

Normal

Abnormal

Faulty regulator/rectifier
Poorly connected coupler

Normal voltage
Measure resistance
between AC generator
coil terminals

Connect battery (+) wire
to regulator/rectifier
coupler red wire and
battery (-) wire to engine
ground and test voltage

Check regulator/rectifier
coupler for loose
connection

Faulty A.C. generator

Overcharging
Inspection/Adjustment
Connect battery (+) wire
to regulator/rectifier
coupler green wire and
battery (-) wire to engine
ground and test voltage

Symptom

Probable Cause

Battery has voltage
with ignition
switch “ON”

Battery has no
voltage with ignition
switch “ON”

Normal

Abnormal

Broken green wire

Check regulator/rectifier
coupler for loose
connection
Poorly connected coupler
Faulty regulator/rectifier

1-27

1. GENERAL INFORMATION

MX’er SYSTEM

NO SPARK AT SPARK PLUG
Inspection/Adjustment

Symptom

Probable Cause

Replace with a new
spark plug and inspect
again
Weak or no spark

Good spark

Faulty spark plug

Check spark plug cap
and high-tension wire
for looseness
Not loose

Loose

Loose spark plug cap

Good

Poorly connected coupler

Normal

Abnormal

Check CDI unit coupler
for looseness

Measure resistance
between terminals of
CDI unit coupler

Check related parts

Normal

Abnormal

Faulty ignition switch
Weak battery
Faulty pulser coil
Faulty ignition coil
Faulty charging system
Broken wire harness
Poorly connected coupler

Check CDI unit with a
CDI unit tester
Normal

Abnormal

Faulty CDI unit
Faulty change gear control
unit

Check ignition coil with
a CDI unit tester
Abnormal

Faulty ignition coil

1-28

2. FRAME COVERS/EXHAUST MUFFLER

MX’er SYSTEM

2
__________________________________________________________________________________

____________________________________________________________________

FRAME COVERS/EXHAUST MUFFLER
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------TROUBLESHOOTING----------------------------------------------------FRAME COVERS ----------------------------------------------------------HEADLIGHT REMOVAL ------------------------------------------------EXHAUST MUFFLER REMOVAL--------------------------------------

2- 2
2- 2
2- 3
2- 5
2- 5

2-0

2. FRAME COVERS/EXHAUST MUFFLER

2-1

MX’er SYSTEM

2. FRAME COVERS/EXHAUST MUFFLER

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

2-2

2. FRAME COVERS/EXHAUST MUFFLER

MX’er SYSTEM
Seat

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.

Bolt

Screws

During removal, do not pull the joint
claws forcedly to avoid damage.

Bolt

Remove the left rear fender under bolt.
Remove the left rear fender.

Bolt

RIGHT REAR FENDER REMOVAL
Remove seven screws and two bolts
attaching the right rear fender.
During removal, do not pull the joint
claws forcedly to avoid damage.

2-3

Frame Right Cover

Frame Left Cover

2. FRAME COVERS/EXHAUST MUFFLER

MX’er SYSTEM

Remove right rear fender under bolt.
Remove the right rear fender.

Bolt

FLOOR BOARD COVER REMOVAL
Remove the four bolts on the floorboard
cover.
Remove the floorboard cover.

Floor Board Cover

Bolts
Front 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.

Screws

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.
During removal, be careful not to
damage the joint claws.
Bolt

2-4

2. FRAME COVERS/EXHAUST MUFFLER

MX’er SYSTEM

HEADLIGHT REMOVAL
Remove the headlight connector wire.
Remove the two bolts on the headlight.

Bolts

EXHAUST MUFFLER
REMOVAL
Remove the two bolts attaching the exhaust
muffler.

Bolts
Joint Lock Nuts

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
Be sure to install a new exhaust muffler
packing collar.

2-5

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

3
__________________________________________________________________________________

____________________________________________________________________

INSPECTION/ADJUSTMENT
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------MAINTENANCE SCHEDULE-------------------------------------------FUEL LINE/THROTTLE OPERATION/AIR CLEANER -----------AIR FILTER FOR DRIVE BELT ----------------------------------------SPARK PLUG---------------------------------------------------------------VALVE CLEARANCE/CARBURETOR IDLE SPEED--------------IGNITION TIMING/CYLINDER COMPRESSION ------------------ENGINE OIL/FINAL REDUCTION GEAR OIL----------------------DRIVE BELT/BRAKE SHOE/BRAKE SYSTEM --------------------HEADLIGHT AIM ---------------------------------------------------------STEERING SYSTEM INSPECTION------------------------------------TOE-IN ADJUSTMENT --------------------------------------------------WHEELS/TIRES -----------------------------------------------------------DRIVE CHAIN SLACK ADJUSTMENT-------------------------------CABLE INSPECTION AND LUBRICATION-------------------------FRONT SUSPENSION LUBRICATION --------------------------------

3- 1
3- 2
3- 3
3- 4
3- 5
3- 6
3- 7
3- 8
3- 9
3-11
3-11
3-12
3-13
3-14
3-16
3-16

3-0

3. INSPECTION/ADJUSTMENT

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
Spark plug gap
Spark plug: Standard
Valve clearance

: 1 4mm
: 0.6 0.7mm
: NGK: CR8E
: IN: 0.06mm
EX: 0.06mm
: 1700±100rpm

Idle speed
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
Front

1 Rider
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

3-1

3. INSPECTION/ADJUSTMENT

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.
Item
Valves
Spark plug
Air clearance
Carburetor
Fuel line
Engine oil

Initial
Every
1
3
6
6
1
month month month month year

Remarks
Check valve clearance. Adjust if
necessary.
Check condition. Clean or replace if
necessary.
Clean. Replace if necessary.
Check idle speed/starter operation.
Adjust if necessary.
Check fuel hose for cracks or
damage. Replace if necessary.
Replace (Warm engine before
draining).

Engine oil filter screen Clean. Replace if necessary.
Check oil leakage. Replace every
Transmission oil
12 months.
Check operation. Adjust if
Brake system
necessary.
Check operation/replace if damage
Drive belt
or excessive wear.
Check balance/damage/runout.
Wheels
Replace if necessary.
Check bearings assembly for
Wheel bearings
looseness/damage. Replace if
damaged.
Check operation/replace if damage.
Steering system
Check toe-in/adjust if necessary.
Knuckle shafts
Fitting/Fasteners

Lubricate every 6 months.
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.

3-2

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

Check the fuel tubes and replace any parts,
which show signs of deterioration, damage
or leakage.
Do not smoke or allow flames or sparks
in your working area.

Fuel Filter

THROTTLE OPERATION
Check the throttle to swing for smooth
movement.
Measure the throttle to swing free play.
Free Play: 1 4mm

Adjusting Nut

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.

Lock Nut
Screws

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.
Air Cleaner Case Cover

Fuel tube

3-3

CLEAN AIR FILTER ELEMENT
Wash the element gently, but throughly in
solvent.

3. INSPECTION/ADJUSTMENT

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.
Do not twist or wring out the foam
element. This could damage the foam
material.
Apply the engine oil.
Squeeze out the excess oil.
The element should be wet but not
dripping.

Air Cleaner Element

CHANGE INTERVAL
More frequent replacement is required when
riding in unusually dusty or rainy areas.

AIR FILTER FOR DRIVE BELT

Front cover

Air Filter Case

Remove the front cover.
Remove the screw, air filter case and air
filter element.
Inspect the air filter element.
Replace if damage.

Screw

Clean air filter element steps:
Tap the element lightly to remove most of

3-4

3. INSPECTION/ADJUSTMENT

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.
Specified Spark Plug: NGK: CR8E

Measure the spark plug gap.
Spark Plug Gap: 0.6 0.7mm

Gap, Wear, and Fouling Deposits

When installing, first screw in the spark
plug by hand and then tighten it with a
spark plug wrench.

Washer Deformation

Cracks, Damage

VALVE CLEARANCE
Inspect and adjust valve clearance while
the engine is cold (below 35 ).

3-5

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

Remove the cylinder head cover.

Bolts

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.

Punch Marks
Valve Wrench

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
Special

Tappet adjuster

E012

• Check the valve clearance again after
the lock nut is tightened.

CARBURETOR IDLE SPEED

Throttle Stop Screw

• The engine must be warm for accurate
idle speed inspection and adjustment.
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.
Throttle Stop Screw

Cylinder Head Cover

IGNITION TIMING
The CDI unit is not adjustable. If the
ignition timing is incorrect, check the
ignition system.

3-6

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

Remove the timing hole cap.

Timing Light

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.

Compression Gauge

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.

Timing Hole Cap

ENGINE OIL
OIL LEVEL

3-7

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

• 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.
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 Dipstick

Upper Level
Oil Filter Screen Cap

OIL CHANGE
The engine oil will drain more easily
while the engine is warm.
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#

oil drain plug bolt
Oil Filler Bolt

FINAL REDUCTION GEAR OIL
Place the motorcycle on level ground for
oil level check.
Recommended Oil: GEAR OIL SAE90#

Lower Level

GEAR OIL CHANGE
Remove the oil filler bolt.
Removes the oil drains bolt and drain the oil

3-8

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

thoroughly.
Install the oil drain bolt.
Torque: 0.8 1.2kgf-m
Make sure that the sealing washer is in
good condition.
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

Oil Drain Bolt/ Sealing Washer

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.
Drive Belt

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.

Wear Indicator

Punch Mark

BRAKE SYSTEM
FRONT BRAKE
Measure the front brake lever free play.
Free Play: 10 20mm
Adjust if out of specification.

Adjust brake lever free play:
Loosen the lock nuts.

3-9

3. INSPECTION/ADJUSTMENT

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.
Make sure that the brake does not drag
after adjusting.

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.

Adjusting Nut
Lock Nuts

Adjusters

HEADLIGHT AIM
Turn the ignition switch ON and start the

3-10

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

engine.
Turn on the headlight switch.
Adjust the headlight aim by turning the
headlight aim adjusting screw.

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.

Tie-rod Ends

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.

TOE-IN ADJUSTMENT
Place the machine on a level place.
Measure the toe-in

3-11

3. INSPECTION/ADJUSTMENT

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

Tie-rod

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

Tie-rod End Nuts

• 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.

WHEELS/TIRES
Check the tires for cuts, imbedded nails or
other damages.
Check the tire pressure.

3-12

3. INSPECTION/ADJUSTMENT

MX’er SYSTEM

Tire pressure should be checked when
tires are cold.

Front Axle Nut

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

Rear Axle Nut

: 6.0 8.0kgf-m

WHEEL INSPECTION
Inspect the tire surfaces.
Replace if wear or damage.
Tire wear limit: 3.0mm

It is dangerous to ride with a worn out
tire. When a tire wear is out of
specification, replace the tire
immediately.

Inspect the wheel.
Replace if damage or bends
Always balance the wheel when a tire or
wheel has been changed or replaced.

3-13

• Never attempt even small repairs to the
wheel.
• Ride conservatively after installing a
tire to allow it to seat itself properly on

3. INSPECTION/ADJUSTMENT

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.
Too little of chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.
Place the machine on a level place.
Wheels should be on the ground without
the rider on it.
Check drive chain slack.
Adjust if out of specification.
Drive chain slack: Approximately 30mm

Bolts

Adjust drive chain slack:
Elevate the rear wheels by placing a suitable
stand under the rear of frame.
Support the machine securely so there is
no danger of it falling over.
Loosen four bolts attaching rear axle hub.

Turn the adjuster in or out until the
specified slack is obtained.

3-14

3. INSPECTION/ADJUSTMENT

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

Bolts

Adjuster

Tighten the adjuster.
Torque: 1.8 2.5kgf-m

Adjuster

CABLE INSPECTION AND
LUBRICATION

3-15

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

MX’er SYSTEM

Inspect the cable sheath.
Replace if damage.
Check the cable operation.
Lubricate or replace if unsmooth operation.
Hold cable end high and apply several
drops of lubricant to cable.

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.
Wipe off the excess grease.

Nipple

3-16

4. LUBRICATION SYSTEM

MX’er SYSTEM

4
__________________________________________________________________________________

____________________________________________________________________

LUBRICATION SYSTEM
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------TROUBLESHOOTING----------------------------------------------------ENGINE OIL/OIL FILTER -----------------------------------------------OIL PUMP --------------------------------------------------------------------

4- 2
4- 2
4- 3
4- 3

4-0

4. LUBRICATION SYSTEM

MX’er SYSTEM

LUBRICATION SYSTEM

Rocker Arm Shaft

Crankshaft

Oil Filter Screen

4-1

Oil Pump

4. LUBRICATION SYSTEM

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
Inner rotor-to-outer rotor clearance
Oil pump Outer rotor-to-pump body clearance
Rotor end-to-pump body clearance

Standard (mm)

Service Limit (mm)

⎯

0.12

⎯

0.12

0.05 0.10

0.2

TROUBLESHOOTING
Oil level too low
• Natural oil consumption
• Oil leaks
• Worn or poorly installed piston rings
• Worn valve guide or seal

Poor lubrication pressure
• Oil level too low
• Clogged oil filter or oil passages
• Not use the specified oil

4-2

4. LUBRICATION SYSTEM

MX’er SYSTEM
Lower Level

ENGINE OIL/OIL FILTER
OIL 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.
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 Dipstick

Upper Level
Oil Filter Screen Cap

oil drain plug bolt

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.

Nut

OIL PUMP
REMOVAL
Remove the right crankcase cover.
Remove the A.C. generator flywheel.
Special

Flywheel holder
Flywheel puller

4-3

E021
E003

Flywheel

4. LUBRICATION SYSTEM
Remove the starter idle gear and starter
clutch.

MX’er SYSTEM
Starter Clutch

Starter Idle Gear

Special

Lock nut socket wrench

E009

Remove the two bolts and oil separator
cover.

Bolts

Oil Separator Cover

Remove the oil pump driven gear nut to
remove the oil pump driven gear and drive
chain.

Nut

Oil Pump Driven Gear
Bolts

Remove the oil pump mounting two bolts
and the oil pump.

Oil Pump

4-4

4. LUBRICATION SYSTEM
DISASSEMBLY
Remove the screw and disassemble the oil
pump.

MX’er SYSTEM
Screw

Pump Body

INSPECTION
Measure the pump body-to-outer rotor
clearance.
Service Limit: 0.12mm

Outer Rotor

Pump Body
Outer Rotor

Measure the inner rotor-to-outer rotor
clearance.
Service Limit: 0.12mm

Inner Rotor

Measure the rotor end-to-pump body
clearance.
Service Limit: 0.2mm

4-5

4. LUBRICATION SYSTEM
ASSEMBLY
Install the outer rotor, inner rotor and pump
shaft into the pump body.

MX’er SYSTEM
Outer Rotor

Inner Rotor

Insert the pump shaft by aligning the flat
on the shaft with the flat in the inner
rotor.
Install the dowel pin.
Install the pump cover by aligning the hole
in the cover with the dowel pin.
Pump Cover

Dowel Pin
Screw

Tighten the screw to secure the pump cover.
Make sure that the pump shaft rotates freely
without binding.

Oil Pump

Arrow

INSTALLATION
Install the oil pump into the crankcase.
Install the oil pump with the arrow on
the pump body facing up and fill the oil
pump with engine oil before installation.

After the oil pump is installed, tighten the
two mounting bolts.

Bolts

4-6

4. LUBRICATION SYSTEM

MX’er SYSTEM

Install the pump driven gear and drive chain
by aligning the pump driven gear with the
cutout in the pump shaft.
Install and tighten the pump driven gear nut.
Torque: 0.8 1.2kgf-m

Nut

Pump Driven Gear

Install the oil separator cover and tighten
the bolts.

Bolts

Oil Separator Cover

Install the starter idle gear and starter
clutch.
Install the starter clutch nut and tighten it to
specified torque..

Dowel Pin

Torque: 9.5 kgf-m
Install the gasket and dowel pins.

Starter Idle Gear

Starter Clutch

Install the A.C. generator flywheel.
Install the right crankcase cover.
Torque: 0.8 1.2kgf-m
Diagonally tighten the bolts in 2 3
times.

Flywheel

4-7

Gasket

5. FUEL SYSTEM

MX’er SYSTEM

5
__________________________________________________________________________________

____________________________________________________________________

FUEL SYSTEM
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------TROUBLESHOOTING----------------------------------------------------THROTTLE VALVE DISASSEMBLY/CARBURETOR REMOVAL-FLOAT/FLOAT VALVE/JETS-------------------------------------------CARBURETOR INSTALLATION --------------------------------------FUEL TANK ----------------------------------------------------------------FUEL VALVE REMOVAL -----------------------------------------------AIR CLEANER --------------------------------------------------------------

5- 2
5- 3
5- 4
5- 5
5- 8
5- 9
5- 9
5-10

5-0

5. FUEL SYSTEM

5-1

MX’er SYSTEM

5. FUEL SYSTEM

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
Item
Type
Venturi dia.
Float level
Main jet No.
Adjust method
Idle speed
Throttle grip free play
Air screw opening

MX’er 150

MX’er 125

Standard
PD
φ25
14.8mm
95
Piston
1700±100rpm
1 4mm
2±1/2

5-2

5. FUEL SYSTEM

MX’er SYSTEM

SPECIAL TOOL
Float level gauge

TROUBLESHOOTING
Engine cranks but won’t start
• No fuel in tank
• No fuel to carburetor
• Cylinder flooded with fuel
• No spark at plug
• Clogged air cleaner
• Intake air leak
• Improper throttle operation
Engine idles roughly, stalls or runs poorly
• Excessively used choke
• Ignition malfunction
• Faulty carburetor
• Poor quality fuel
• Lean or rich mixture
• Incorrect idle speed
Misfiring during acceleration
• Faulty ignition system
• Faulty carburetor

Backfiring at deceleration
• Float level too low
• Incorrectly adjusted carburetor
• Faulty exhaust muffler

5-3

Engine lacks power
• Clogged air cleaner
• Faulty carburetor
• Faulty ignition system
Lean mixture
• Clogged carburetor fuel jets
• Float level too low
• Intake air leak
• Clogged fuel tank cap breather hole
• Kinked or restricted fuel line
Rich mixture
• Float level too high
• Clogged air jets
• Clogged air cleaner

5. FUEL SYSTEM
THROTTLE VALVE DISASSEMBLY

MX’er SYSTEM
Carburetor Cap

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.

Spring

Throttle Cable

Throttle Valve
Clip

Pry off the needle retainer and remove the jet
needle.
Check the throttle valve and jet needle for
wear or damage.

Throttle Valve

Needle Retainer

Jet Needle

Choke Cable

CARBURETOR REMOVAL
Switch the fuel valve OFF.
Loosen the drain screw to drain the gasoline
from the float chamber.
• Keep sparks and flames away from the
work area.
• Drain gasoline into a clean container.
Disconnect the fuel inlet tube and the choke
cable.

5-4

5. FUEL SYSTEM

MX’er SYSTEM
Lock Nuts

Loosen the air cleaner connecting tube band
screw.
Remove the two carburetor lock nuts.
Remove the carburetor

Screw

FLOAT/FLOAT VALVE/JETS
FLOAT/FLOAT VALVE DISASSEMBLY
Remove the float chamber attaching three
screws and remove the float chamber.

Screws

Remove the float pin, float and float valve.

Float

Float Pin

Float Valve
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.

Float Valve Seat

5-5

5. FUEL SYSTEM

MX’er SYSTEM
Slow Jet

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.

Air Screw

CAUTIONS !

Air Screw

Main Jet

Throttle Stop Screw

O-ring

Slow Jet

• 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.
Spring

Washer Throttle Spring
Stop Screw

Main Jet

FUEL RESERVOIR O-RING CHECK
Remove the O-ring.
INSPECTION
Inspect the check the O-ring for damage.
Replace with new ones if necessary

O-ring

CARBURETOR CLEANING
Blow compressed air through all passages of
the carburetor body.

5-6

5. FUEL SYSTEM

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

Slow Jet

Main Jet

• 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 Stop Screw

Air Screw

Float

Install the float valve, float and float pin.

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 Gauge

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.

5-7

5. FUEL SYSTEM

MX’er SYSTEM
Lock Nut

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.

Band Screw
Clip

THROTTLE VALVE ASSEMBLY

Needle Retainer

Install the jet needle into the throttle valve
and secure with the needle retainer.
Jet Needle Notch: 4th Notch
(Counted from top to bottom)

Throttle Valve

Jet Needle

Carburetor Cap

Spring

Assemble the rubber cover, carburetor cap
and throttle valve spring.
Connect the throttle cable to the throttle
valve.

Throttle Valve

Notch
Groove

Install the throttle valve into the carburetor
body.
Align the groove in the throttle valve
with the throttle stop screw on 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.
Throttle Stop Screw

5-8

5. FUEL SYSTEM

MX’er SYSTEM
Screw

Tighten the choke cable.

FUEL TANK
FUEL TANK REMOVAL

Choke Cable
Side

• Keep sparks and flames away from the
work area.
• Wipe off any spilled gasoline.
Remove the seat.
Remove the center cover.
Remove the right and left front fender.

Bolts

Fuel Tank

Switch the fuel valve “OFF”.
Disconnect the fuel tube and remove two
bolts on the end of the fuel tank.
Remove the fuel tank.

Tube
Fuel Valve

FUEL VALVE REMOVAL
Remove the fuel valve and fuel cup.

5-9

5. FUEL SYSTEM
Remove the screw on the fuel valve control
switch.
Remove the two screws on the fuel valve
body.

MX’er SYSTEM
Fuel Valve Body

Washer

Control Switch

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.
Rubber Gasket

AIR CLEANER

Control Shaft Retaining Ring

Air Cleaner Case Cover

REMOVAL
Remove the seat.
Remove the four screws on the air cleaner
case cover and the cover.
Remove the air cleaner screen and element.

Screws

5-10

6. ENGINE REMOVAL/INSTALLATION

MX’er SYSTEM

6
__________________________________________________________________________________

____________________________________________________________________

ENGINE REMOVAL/INSTALLATION

____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 6- 1
ENGINE REMOVAL ------------------------------------------------------- 6- 2
ENGINE INSTALLATION ------------------------------------------------ 6- 4

6-0

6. ENGINE REMOVAL/INSTALLATION

MX’er SYSTEM

SERVICE INFORMATION
GENERAL INSTRUCTIONS
• A floor jack or other adjustable support is required to support and maneuver the engine.
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

6-1

6. ENGINE REMOVAL/INSTALLATION

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.

Starter Relay

Starter Motor Cable

Disconnect the starter motor cable from the
starter relay.

Oil Recycle Tube

Disconnect the oil recycle tube at the engine
body.
Disconnect the oil recycle tube at the
cylinder head cover.

Oil Recycle Tube
Connecting Tube

Loosen the drive belt air cleaner connecting
tube band screw and remove the connecting
tube.

Screw

A.C.G. Wire Connector

6-2

6. ENGINE REMOVAL/INSTALLATION

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.

Ignition Coil Wire

Remove the rear drive chain gear on the
bolts.
Remove the drive chain gear.

Drive Chain Gear

Bolts
Exhaust Muffler

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.

6-3

Bolts

6. ENGINE REMOVAL/INSTALLATION

MX’er SYSTEM

Remove the engine front bracket bolt.

Bolt
Engine Hanger Bracket

ENGINE HANGER BRACKET
REMOVE
Remove the two bolts on the left engine
hanger bracket.
Remove the left engine hanger bracket.
Remove the engine.

Bolts

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.
Route the wires and cables properly.

6-4

7. CYLINDER HEAD/VALVES

MX’er SYSTEM

7
__________________________________________________________________________________

____________________________________________________________________

CYLINDER HEAD/VALVES
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------TROUBLESHOOTING----------------------------------------------------CAMSHAFT REMOVAL -------------------------------------------------CYLINDER HEAD REMOVAL -----------------------------------------CYLINDER HEAD DISASSEMBLY -----------------------------------CYLINDER HEAD ASSEMBLY ----------------------------------------CYLINDER HEAD INSTALLATION ----------------------------------CAMSHAFT INSTALLATION -------------------------------------------

7- 2
7- 3
7- 4
7- 7
7- 8
7-10
7-10
7-11

7-0

7. CYLINDER HEAD/VALVES

7-1

MX’er SYSTEM

7. CYLINDER HEAD/VALVES

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
IN
Valve clearance (cold)
EX
Cylinder head compression pressure
Cylinder head warpage
IN
Camshaft cam height
EX
Valve rocker arm to shaft clearance
Valve stem-to-guide
IN
clearance
EX
IN
Valve spring free length
EX
Valve spring
IN
compressed force
EX
IN
Valve spring tilt
EX

Standard (mm)
0.06
0.06
16kg/cm²
⎯
31.8
31.53
0.09 0.034
0.010 0.037
0.025 0.052
39.4
45.5
7.7 8.9kg(at 33.7mm)
19.5 22.5kg(at 38.4mm)
1.7
1.95

Service Limit (mm)
⎯
⎯
0.05
31.4
31.13
0.1
0.06
0.08
⎯
⎯
⎯
⎯
⎯
⎯

7-2

7. CYLINDER HEAD/VALVES
TORQUE VALUES
Cylinder head nut
Valve clearance adjusting nut
Stud bolt

1.8 2.2kgf-m
1.4 1.8kgf-m
0.7 1.1kgf-m

SPECIAL TOOLS
Valve spring compressor
Tappet adjuster

MX’er SYSTEM

Apply engine oil to threads
Apply engine oil to threads

E040
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
• Compression too low
Compression too low
• Incorrect valve clearance adjustment
• Burned or bend valves
• Incorrect valve timing
• Broken valve spring
• Poor valve and seat contact
• Leaking cylinder head gasket
• Warped or cracked cylinder head
• Poorly installed spark plug
Compression too high
• Excessive carbon build-up in combustion
chamber

7-3

White smoke from exhaust muffler
• Worn valve stem or valve guide
• Damaged valve stem seal
Abnormal noise
• Incorrect valve clearance adjustment
• Sticking valve or broken valve spring
• Damaged or worn camshaft
• Worn cam chain guide
• Worn camshaft and rocker arm

7. CYLINDER HEAD/VALVES

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.

Bolts

Remove the cam chain tensioner cap bolt
and the O-ring.

Bolt
O-ring

Turn the cam chain tensioner screw
clockwise to tighten it.

Tensioner Screw

Camshaft Gear

Round Hole

Punch Marks

Cylinder Head Cover

7-4

7. CYLINDER HEAD/VALVES

MX’er SYSTEM

Remove the four cylinder head nuts and
washers.
Diagonally loosen the cylinder head nuts
in 2 or 3 times.

Washer

Remove the camshaft holder and dowel
pins.

Remove the camshaft gear from the cam
chain and remove the camshaft.

Camshaft Holder

Camshaft

Dowel Pins

Cam Chain

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

7-5

Nut

Camshaft Gear

7. CYLINDER HEAD/VALVES

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.

Rocker Arm

Bolt

Rocker Arm Shaft

CAMSHAFT HOLDER INSPECTION
Inspect the camshaft holder, valve rocker
arms and rocker arm shafts for wear or
damage.

Camshaft Holder

If the valve rocker arm contact surface is
worn, check each cam lobe for wear or
damage.

Rocker Arm Shafts

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

Camshaft Bearings

7-6

7. CYLINDER HEAD/VALVES
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.

MX’er SYSTEM
Intake Manifold

Bolts
Cylinder Head

Bolts
Cam Chain Guide

Cylinder Head Gasket

Remove all gasket material from the
cylinder mating surface.
• Avoid damaging the cylinder mating
surface.
• Be careful not to drop any gasket
material into the engine.

7-7

Dowel Pins

7. CYLINDER HEAD/VALVES
CYLINDER HEAD
DISASSEMBLY

MX’er SYSTEM
Valve Spring Compressor

Remove the valve spring cotters, retainers,
springs, spring seats and valve stem seals
using a valve spring compressor.
• Be sure to compress the valve springs
with a valve spring compressor.
• Mark all disassembled parts to ensure
correct reassembly.
Special

Valve Spring Compressor

E040

Valve Spring Compressor

Remove carbon deposits from the
combustion chamber.
Clean off any gasket material from the
cylinder head mating surface.
Be careful not to damage 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.

7-8

7. CYLINDER HEAD/VALVES
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
If the stem-to-guide clearance exceeds
the service limits, replace the cylinder
head as necessary.

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

7-9

MX’er SYSTEM

7. CYLINDER HEAD/VALVES

MX’er SYSTEM

CYLINDER HEAD ASSEMBLY
Install the valve spring seats and valve stem
seals.
Be sure to install new valve stem seals.
Lubricate each valve stem with engine oil
and insert the valves into the valve guides.
Install the valve springs and retainers.

Valve Spring Compressor

Compress the valve springs using the valve
spring compressor, then install the valve
cotters.
• When assembling, a valve spring
compressor must be used.
• Install the cotters with the pointed ends
facing down from the upper side of the
cylinder head.
Special

Valve Spring Compressor

E040

Tap the valve stems gently with a plastic
hammer for 2 3 times to firmly seat the
cotters.
Be careful not to damage the valves.

Dowel Pins

Gasket

CYLINDER HEAD
INSTALLATION
Install the dowel pins and a new cylinder
head gasket.
Install the cam chain guide.

Cam Chain Guide

7-10

7. CYLINDER HEAD/VALVES

MX’er SYSTEM

Install two cylinder head bolts do not
tighten completely.
Install the cylinder head.
Torque: Stud Bolts :0.8 1.2kgf-m

Bolts

Cylinder Head

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 Holder

• Align the cutout on the front end of the
intake valve rocker arm shaft with the
bolt of the camshaft holder.
• Align the cross cutout on the exhaust
valve rocker arm shaft with the bolt of
the camshaft holder.
Valve Rocker Arm

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.

Cam Chain

Round Hole

Camshaft Gear

Punch Marks
Dowel Pins

Install the dowel pins.

7-11

7. CYLINDER HEAD/VALVES
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

MX’er SYSTEM
Nut

Camshaft Holder

• Apply engine oil to the threads of the
cylinder head nuts.
• Diagonally tighten the cylinder head
nuts in 2 3 times.
Washer

Adjust the valve clearance.
Turn the cam chain tensioner screw
counter-clockwise to release it.

Tensioner Screw

Apply engine oil to a new O-ring and install
it.
Tighten the cam chain tensioner cap bolt.
Be sure to install the O-ring into the
groove properly.

Bolt

Install a new cylinder head cover O-ring
and install the cylinder head cover.
Install and tighten the cylinder head cover
bolts.
Be sure to install the O-ring into the
groove properly.

Cylinder Head Cover

7-12

8. CYLINDER/PISTON

MX’er SYSTEM

8
__________________________________________________________________________________

____________________________________________________________________

CYLINDER /PISTON
____________________________________________________________________

SERVICE INFORMATION-----------------------------------------------TROUBLESHOOTING----------------------------------------------------CYLINDER REMOVAL --------------------------------------------------PISTON REMOVAL-------------------------------------------------------PISTON INSTALLATION------------------------------------------------CYLINDER INSTALLATION --------------------------------------------

8- 2
8- 2
8- 4
8- 4
8- 8
8- 8

8-0

8. CYLINDER/PISTON

8-1

MX’er SYSTEM

8. CYLINDER/PISTON

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

Compression too high

Abnormal noisy piston

• Excessive carbon build-up in combustion
chamber or on piston head

• Worn cylinder, piston and piston rings
• Worn piston pin hole and piston pin

8-2

8. CYLINDER/PISTON

MX’er SYSTEM

SPECIFICATIONS
Mx’er 150
I.D.
Warpage
Cylinder
Cylindricity
True roundness
Ring-to-groove Top
clearance
Second
Top
Ring end gap
Second
Piston,
piston ring
Oil side rail
Piston O.D.
Piston O.D. measuring position
.
Piston-to-cylinder clearance
Piston pin hole I.D.
Piston pin O.D
Piston-to-piston pin clearance
Connecting rod small end I.D. bore

Mx’er 125
I.D.
Warpage
Cylinder
Cylindricity
True roundness
Ring-to-groove Top
clearance
Second
Top
Ring end gap
Second
Piston,
piston ring
Oil side rail
Piston O.D.
Piston O.D. measuring position
.
Piston-to-cylinder clearance
Piston pin hole I.D.
Piston pin O.D
Piston-to-piston pin clearance
Connecting rod small end I.D. bore

8-3

Standard (mm)
Service Limit (mm)
62.03 62.045
⎯
⎯
0.05
⎯
0.05
⎯
0.05
0.015 0.055
0.09
0.015 0.055
0.09
0.10 0.25
0.5
0.10 0.25
0.5
0.2 0.7
⎯
61.96 62
⎯
5mm from bottom of skirt
⎯
0.010 0.040
0.1
15.002 15.008
15.04
14.994 15.000
14.96
0.002 0.014
0.02
15.016 15.034
15.06

Standard (mm)
Service Limit (mm)
56.53 56.545
⎯
⎯
0.05
⎯
0.05
⎯
0.05
0.015 0.055
0.09
0.015 0.055
0.09
0.10 0.25
0.5
0.10 0.25
0.5
0.2 0.7
⎯
56.46 56.5
⎯
5mm from bottom of skirt
⎯
0.010 0.040
0.1
15.002 15.008
15.04
14.994 15.000
14.96
0.002 0.014
0.02
15.016 15.034
15.06

8. CYLINDER/PISTON
CYLINDER REMOVAL

MX’er SYSTEM
Bolt

Turn the cam chain tension screw clockwise
to tighten it.
Remove the two bolts on the cam chain
tension.

Cylinder

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.

Dowel Pins

PISTON REMOVAL

Piston

Remove the piston pin clip.
Place a clean shop towel in the crankcase
to keep the piston pin clip from falling
into the crankcase.
Press the piston pin out of the piston and
remove the piston.
Piston Pin Clip

8-4

8. CYLINDER/PISTON
Inspect the piston, piston pin and piston
rings.
Remove the piston rings.
Take care not to damage or break the
piston rings during removal.
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.
Use the piston head to push each piston
ring into the cylinder.
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

8-5

MX’er SYSTEM

8. CYLINDER/PISTON

MX’er SYSTEM
over

Measure the piston pin O.D.
Service Limit: 14.96mm replace if below

Measure the piston O.D.
Take measurement at 5mm from the
bottom and 90° to the piston pin hole.
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

Top
Middle
Bottom

8-6

8. CYLINDER/PISTON

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.

Top
Second
Side Rail
Oil Ring
Side Rail

8-7

8. CYLINDER/PISTON

MX’er SYSTEM

PISTON INSTALLATION
Remove any gasket material from the
crankcase surface.
Be careful not to drop foreign matters
into the crankcase.

Piston

Install the piston, piston pin and a new
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.

Piston Pin Clip

CYLINDER INSTALLATION

Piston Pin

Cylinder

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.
• Be careful not to damage or break the
piston rings.
• Stagger the ring end gaps at 120° to the
piston pin.
Gasket

Install the cam chain tension.
Tighten the cam chain tension bolts.

Bolts

8-8

8. CYLINDER/PISTON

8-9

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS

MX’er SYSTEM

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

9-0

9. DRIVE AND DRIVEN PULLEYS

MX’er SYSTEM

5.5kg-m

9-1

9. DRIVE AND DRIVEN PULLEYS

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

Remove any oil or grease from

SPECIFICATIONS
Item
Movable drive face bushing I.D.
Drive face collar O.D.
Drive belt width
Clutch lining thickness
Clutch outer I.D.
Driven face spring free length
Driven face O.D.
Movable driven face I.D.
Weight roller O.D.

Standard (mm)
27.0 27.021
26.97 26.99
20.0 21.0
⎯
130.0 130.2
⎯
33.965 33.485
34.000 34.025
20.95 21.1

Service Limit (mm)
27.06
226.94
19.0
2.0
130.5
83.2
33.94
34.06
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

• 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

9-2

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS
LEFT CRANKCASE COVER

Air Tube Band

REMOVAL
Loosen the drive belt air tube band screw.

Screw

Remove the left crankcase cover bolts and
left crankcase cover.
Remove the gasket and dowel pins.

Left Crankcase Cover

Bolts

DRIVE PULLEY

Drive Pulley Face

Nut

REMOVAL
Hold the drive pulley using an universal
holder and remove the drive face nut and
starting ratchet.
Remove the drive pulley face.
Special

Universal Holder

E017
Universal Holder
Clutch Outer

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.
Special

Universal Holder

E017
Universal Holder

9-3

9. DRIVE AND DRIVEN PULLEYS

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
Use specified genuine parts for
replace-ment.

Remove the movable drive face assembly.
Remove the drive pulley collar.

Drive Pulley Collar

Movable Drive Face Assembly
Ramp Plate

DISASSEMBLY
Remove the ramp plate.

Weight Rollers

Remove the weight rollers.

9-4

9. DRIVE AND DRIVEN PULLEYS
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

9-5

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS

MX’er SYSTEM

ASSEMBLY

Install the weight rollers into the movable
drive face.

Weight Roller
Ramp Plate

Install the ramp plate.

9-6

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS
Insert the drive pulley collar into the movable
drive face.

Drive Pulley Collar

INSTALLATION
Install the movable drive face onto the
crankshaft.

Movable Drive Face Assembly

INSPECTION
Inspect the clutch outer for wear or damage.
Measure the clutch outer I.D.
Service Limit: 130.5mm replace if over

Clutch

CLUTCH/DRIVEN PULLEY
DISASSEMBLY

Driven Pulley

9-7

9. DRIVE AND DRIVEN PULLEYS

MX’er SYSTEM
Clutch Spring Compressor

Hold the clutch/driven pulley assembly with
the clutch spring compressor.
Be sure to use a clutch spring
compressor to avoid spring damage.
Special

Clutch Spring Compressor

E027

Set the clutch spring compressor in a vise and
remove the clutch drive plate nut.
Lock Nut Wrench

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.

O-ring

Guide Roller Pin

Movable Driven Face

9-8

9. DRIVE AND DRIVEN PULLEYS
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

9-9

MX’er SYSTEM
Oil Seal

9. DRIVE AND DRIVEN PULLEYS

MX’er SYSTEM
Inner Bearing

DRIVEN PULLEY FACE BEARING
REPLACEMENT
Drive the inner needle bearing out of the
driven pulley face.
Discard the removed bearing and replace
with a new one.

Remove the snap ring and drive the outer
bearing out of the driven face.

Outer Bearing

Discard the removed bearing and replace
with a new one.
Apply grease to the outer bearing.
Drive a new outer bearing into the driven face
with the sealed end facing up.
Special

Bearing Puller

E008

Seat the snap ring in its groove.
Apply grease to the driven face bore areas.
Pack all bearing cavities with 9 9.5g
grease.
Specified grease: Heat resistance 230°C
Press a new needle bearing into the driven
face.
Special

Oil Seal And Bearing Install

E014
Retainer Plate

CLUTCH DISASSEMBLY
Remove the circlips and retainer plate to
disassemble the clutch.
Keep grease off the clutch linings.

Clutch Lining

Circlip

9-10

9. DRIVE AND DRIVEN PULLEYS
CLUTCH / DRIVEN PULLEY ASSEMBLY

9-11

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS
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.

MX’er SYSTEM

Retainer Plate

Drive Plate

Springs

Clutch Weights/Shoes

Circlip

Movable Driven Face

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.

Oil Seal

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.

Guide Roller Pin

Install the seal collar.
Remove any excessive grease.
Be sure to clean the driven face off any
grease.
Set the driven pulley assembly, driven face
spring and clutch assembly onto the clutch
spring compressor.
Align the flat surface of the driven face
with the flat on the clutch drive plate.

Driven Face

9-12

MX’er SYSTEM

9. DRIVE AND DRIVEN PULLEYS

Clutch Spring Compressor

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

Clutch Spring Compressor

Lock Nut Wrench

E027

Clutch

INSTALLATION
Install the clutch/driven pulley onto the drive
shaft.
Keep grease off the drive shaft.

Driven Pulley
Clutch Outer

Install the clutch outer.
Hold the clutch outer with the flywheel
holder.
Install and tighten the clutch outer nut.
Torque: 5.5kg-m
Special

Universal Holder
E017
Install the drive belt.
Universal Holder

Install the drive pulley face, starting ratchet
and drive face nut.

Universal Holder

When installing the drive pulley face,
compress 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.
Nut

T orque: 5.5 6.5kgf-m

9-13

Drive Pulley

9. DRIVE AND DRIVEN PULLEYS
Install the left crankcase cover and tighten the
cover bolts diagonally.
Connect the drive belt air tube and tighten the
band screw.

MX’er SYSTEM
Left Crankcase Cover

Screw

9-14

10. FINAL REDUCTION/
TRANSMISSION SYSTEM

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

10-0

10. FINAL REDUCTION/
TRANSMISSION SYSTEM

10-1

MX’er SYSTEM

10. FINAL REDUCTION/
TRANSMISSION SYSTEM

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
Flywheel puller
Lock nut socket wrench

E021
E005
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

10-2

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION SYSTEM
FINAL REDUCTION DISASSEMBLY
Drain engine oil and transmission gear oil
into a clean container.
Remove the engine.
Remove the right crankcase cover.

Bolts
Starter Motor

Flywheel

Balance Gear

Remove the shift gear spindle.
Remove the flywheel and starter clutch.
Remove the balance gear oil pump and starter
motor.

Oil Pump

Shift Gear Spindle

Remove the left case bolt.

Bolt

Remove the transmission case cover
attaching bolts.

Bolt

Crankcase Cover

10-3

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION SYSTEM
Remove gasket and two dowel pins.

Dowel Pins

FINAL REDUCTION/
TRANSMISSION INSPECTION
Inspect the change gear shaft for wear,
damage or seizure.

Change Gear Shaft

Check the transmission operation.
Repair if unsmooth operation.

Plug

Remove the plug.

Gasket

10-4

10. FINAL REDUCTION/
TRANSMISSION SYSTEM
Remove spring, washer and shift cam
stopper.

Shift Cam Stopper

MX’er SYSTEM

Plug
Transmission fork

Remove the transmission fork shaft and
transmission fork.

Transmission fork shaft

Measure the transmission fork shaft O.D.
Service Limit: 11.936

Measure the transmission fork shaft hole I.D.
Service Limit: 12.058

10-5

Washer

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION SYSTEM
Check the shift cam groove and shift cam
gear.
Replace if wear or damage.

TRANSMISSION GEARS/
CRANKSHAFT REMOVAL

Driver Shaft

Countershaft

Remove the final gear and main shaft.

Main Shaft

GEAR/SHAFT COLLAR INSPECTION
Check each gear and gear teeth for wear,
damage, or poor lubrication.

Remove the counter shaft.

Countershaft

10-6

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION SYSTEM
FINAL REDUCTION INSPECTION
Inspect the countershaft and gear for wear or
damage.

Countershaft Bearing

Drive Shaft

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.

Drive Shaft Bearing

Main Shaft Bearing

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 Shaft Gear

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.
Left Crankcase

10-7

Countershaft Bearing

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION 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.

Transmission Fork

Shift cam

Install the transmission fork shaft into the left
crankcase.

Transmission Fork Shaft

Install the change gear shaft by aligning the
punch mark between with the punch mark of
the shift cam gear.

Mark
Plug

Install shift cam stopper, spring, washer and
plug and tighten the plug.

10-8

10. FINAL REDUCTION/
MX’er SYSTEM

TRANSMISSION SYSTEM
Install the dowel pins and a new gasket onto
the right crankcase.
Tighten the crankcase attaching bolts.
Torque: 0.8 1.2kgf-m

Bolts

Tighten the left crankcase attaching bolt.

Bolts
Oil Filler 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

10-9

Shift Gear Spindle

Cylinder

Right Case Cover

11. CRANKSCASE/CRANKSHAFT/
BALANCE SHAFT

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
11-0

11. CRANKCASE/CRANKSHAFT/
BALANCE SHAFT

11-1

MX’er SYSTEM

11. CRANKSCASE/CRANKSHAFT/
BALANCE SHAFT

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
Item
Connecting rod big end side clearance
Crankshaft Connecting rod big end radial clearance
Run out
TORQUE VALUES
Crankcase bolt
Cam chain tensioner slipper bolt
Cam chain cover bolt

Standard (mm)
0.10 0.35
0 0.008
⎯

Service Limit (mm)
0.55
0.05
0.10

0.8 1.2kgf-m
0.8 1.2kgf-m
0.8 1.2kgf-m

TROUBLESHOOTING
Excessive engine noise
Excessive bearing play

11-2

11. CRANKCASE/CRANKSHAFT/
BALANCE SHAFT

MX’er SYSTEM

CRANKCASE SEPARATION
Remove the left and right crankcase
attaching bolts. (Section 10)
Separate the left and right crankcase halves.
Do not damage the crankcase gasket
surface.

Crankcase Bolts

Remove the gasket and dowel pins.

Gasket

Balance Shaft

Dowel Pins

Remover balance shaft from the left
crankcase.

Crankshaft

11-3

11. CRANKSCASE/CRANKSHAFT/
BALANCE SHAFT

MX’er SYSTEM

Remove the crankshaft and cam chain from
the left crankcase.

Clean off all gasket material from the
crankcase mating surfaces.

Gasket

Avoid damaging 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

11-4

11. CRANKCASE/CRANKSHAFT/
BALANCE SHAFT

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

Play
Play

Radial

Axial

Measure the crankshaft run out.
Service Limit: 0.10mm replace if over

Crankshaft

CRANKCASE/BALANCE SHAFT
ASSEMBLY
Install the cam chain into the left crankcase.
Install the crankshaft and balance shaft into
the left crankcase.

Balance Shaft
Left Crankcase

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

Right Crankcase

11-5

11. CRANKSCASE/CRANKSHAFT/
BALANCE SHAFT

MX’er SYSTEM

Align the mark on the balance gear with the
mark on the crankshaft gear.

Install the right and left case cover.

Right Case Cover

Install the cylinder.

Mark

11-6

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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
12-0

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

12-1

MX’er SYSTEM

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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
Item
Radial
Axial

Front wheel rim run out
Front brake drum I.D
Front brake lining thickness
Tie rod length
Rod-end (tie rod) angle
TORQUE VALUES
Steering stem nut
Swing arm nut
Front wheel nut
Front wheel hub nut
Front shock absorber upper
mount bolt
Front shock absorber lower
mount bolt

6.0
4.0
6.0
6.0

Standard (mm)
⎯
⎯
110
4
266.5
180º

Service Limit (mm)
2.0
2.0
111
1.5
⎯
⎯

8.0kgf-m
5.0kgf-m
8.0kgf-m
8.0kgf-m

3.5 4.5kgf-m
3.5 4.5kgf-m

12-2

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

SPECIAL TOOLS
Oil seal and bearing install

MX’er SYSTEM

E014

TROUBLESHOOTING
Hard steering (heavy)
•Insufficient tire pressure

Steers to one side or does not track straight
• Uneven front shock absorbers
• Bent front arm
• Bent steering knuckle
Poor brake performance
• Incorrectly adjusted brake
• Worn brake linings
• Contaminated brake lining surface
• Worn brake shoes at cam contacting area
• Worn brake drum
• Poorly connected brake arm

12-3

Front wheel wobbling
• Bent rim
• Excessive wheel bearing play
• Bent spoke plate
• Faulty tire
• Improperly tightened axle nut
Soft front shock absorber
• Weak shock springs
• Insufficient damper oil
Front shock absorber noise
• Slider bending
• Loose arm fasteners
• Lack of lubrication

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

FRONT WHEEL

MX’er SYSTEM

Nut

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.

Support the machine securely so there is
no danger of it falling over.
Nuts

Remove the cotter pin.
Remove nut attaching the wheel hub and
washer.
Remove the collar and wheel hub.

Wheel Hub

Front Wheel

FRONT BRAKE DISASSEMBLY

Collar Washer

Wheel Panel Nuts

Hub Nut

Brake Cable

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.

Brake Shoes

REMOVE
Remove brake shoes and springs.
Remove the bolt attaching camshaft lever
and remove camshaft lever.
Remove the wear indicator, camshaft and
Orings

Brake Panel

Camshaft lever

Brake Panel

Wear Indicator

O-rings

Springs

Brake Shoes

12-4

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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
Keep oil or grease off the brake drum.

Side Collar

FRONT WHEEL BEARING
Remove the side collar.

12-5

12. FRONT WHEEL/FRONT BRAKE/FRONT

MX’er SYSTEM

SUSPENSION/STEERING SYSTEM

Remove the dust seal.

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.

Collar

Dust Seal

Side 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.

Wheel Bearing

Pack all bearing cavities with grease.
Drive in the left bearing.
Install the distance collar.
Drive in the right bearing.

Driver Handle

• Do not allow the bearings to tilt while
driving them in.
• Drive in the bearing squarely with the
sealed end facing out.
Special

Oil seal and bearing install

E014
Outer Driver

12-6

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

FRONT BRAKE

MX’er SYSTEM

Brake Lining

FRONT BRAKE LINING INSPECTION
Measure the front brake lining thickness.
Service limit: 2.0mm replace if below
Keep oil or grease off the brake linings.

Camshaft lever

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.

Brake Plate
Brake shoe pivot pin

Oil Seal
Wear Indicator
Springs
Camshaft Hole

INSTALLATION
Reverse the “REMOVAL” procedures.
• 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.

Tighten the bolt for camshaft lever.
Torque: 1.8 2.5kgf-m
Apply the grease onto the o-ring, oil seal
lips, pivot pin of brake shoe and
camshaft.

12-7

O-rings

Camshaft

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

MX’er SYSTEM

Install the brake shoe plate.
Boss

Make sure that the boss on the knuckle
correctly engages with the locating slot
on 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.

Locating Slot

Always use a new cotter pin.
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.

Install the front wheel and tighten the nuts
(wheel).
Torque: 6.0 8.0kgf-m
Tapered wheel nuts are used for front
wheels.
Install the nuts with its tapered side
towards the wheel.

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.

12-8

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

FRONT SUSPENSION

MX’er SYSTEM

Upper Bolt

REMOVAL
Elevate the front wheels by placing a
suitable stand under the frame.
Support the machine securely so there is
no danger of it falling over.
Remove the front wheel, wheel hub, brake
shoe plate.
Remove the upper and lower bolt, then
remove the shock absorber.

Lower Bolt
Tie-rod

Nut

Remove the cotter pin and nut, then remove
tie-rod from steering knuckle.

Steering Knuckle

Cotter pin

Front arm

Nut Steering Knuckle

Cotter pin

Remove cotter pin, nut, washer and bolt,
then remove the steering knuckle, covers,
collar and bush from the front arm.

Bolt
Bush

Washer
Cover

Bush

12-9

Collar

Cover

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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.

Front Arm

Bush

Nuts

Bush

Remove the two nut and two bolt attaching
the front arm, then remove the front arm.

Bolt

Bush

Bolt

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.

12-10

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

MX’er SYSTEM

Inspect the steering knuckle.
Replace if cracks, pitting or damage.

Inspect the front arm.
Replace if cracks, bends or damage.
Do not attempt to straighten a bent arm,
this may dangerously weaken the arm.

Bushes

Inspect bushes.
Replace if wear or damage.

INSTALLATION
Reverse the “REMOVAL” procedures.
Apply the grease onto the bushes, collars
and covers.
Install the front arm nut onto the frame and
tighten the nuts.
Torque: 4.0 5.0kgf-m

12-11

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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.
Always use a new 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.
Always use a new cotter pin.

Bleed Valve

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.

12-12

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

MX’er SYSTEM
Handlebar Cover

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.

Main Switch Lead
Brake 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.

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.

Hook
Screws

Remove the two screws to remove the cover
of the throttle housing.
Disconnect the throttle cable from the lever.

12-13

Cover

Throttle Housing

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING 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.

MX’er SYSTEM

Screws

Handlebar Switch

Headlight Unit

Bolts

Handlebar

Cotter Pin

Remove the cotter pins and nuts attaching
the tie-rods, then remove tie-rods.

Nut
Cotter Pin

Tie-rod

Nut

Cotter Pin
Nut

Remove the cotter pin and nut attaching the
steering column, then remove steering
column and collar.

12-14

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

Cable Holder

MX’er SYSTEM
Collar

Steering Column

Remove the two bolts to remove the cable
holder, steering bracket, collars and steering
column.

Bolts

Steering Bracket

INSPECTION
Inspect the handlebar.
Replace if cracks, bends or damage.

Inspect the steering column.
Replace if bends or damage.
Do not attempt to straighten a bent shaft,
this may dangerously weaken the shaft.

Oil Seal

Inspect the steering brackets and oil seal.
Replace if wear or damage.

Steering Brackets

12-15

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

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

Lock Nut

Indentation Surface

Lock Nut

To Steering Column

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
After making adjustment on both tie rods
be sure to mark them R and L for
identification.

To Knuckle Arm

12-16

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

MX’er SYSTEM

The threads on both rod-end must be of
the same length.

Dust Seal

Inspect the collar, duty seal, snap ring and
bearing.
Replace if wear or damage.

Collar

INSTALLATION
Reverse the “REMOVAL” procedures.
Apply the grease onto the collar, duty
seal, and bearing.

Assembly the steering column and tighten
the two bolts.
Torque: 1.8 2.5kgf-m
Band the lock washer tabs.

12-17

Dust Seal

Bearing

Snap Ring

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING 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.

MX’er SYSTEM

Cotter Pin

Nut

Always use a new cotter pin.

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.
Always use a new cotter pin.

Nut

Tie-rod

Nut

Cotter Pin

Indentation Surface

Be sure that the rod-end on the
indentation surface side is connected to
the steering column.

Headlight Unit

Bolts

Install handlebar and handlebar holder, then
tighten the four bolts.
Torque: 1.8 2.5kgf-m

Bolts

Handlebar

12-18

12. FRONT WHEEL/FRONT BRAKE/FRONT
SUSPENSION/STEERING SYSTEM

• 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.

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.

12-19

MX’er SYSTEM

15. IGNITION SYSTEM

MX’er SYSTEM

15
__________________________________________________________________________________

____________________________________________________________________

IGNITION SYSTEM
____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 15- 2
TROUBLESHOOTING----------------------------------------------------- 15- 3
CDI UNIT INSPECTION--------------------------------------------------- 15- 4
IGNITION COIL------------------------------------------------------------- 15- 6
PULSER COIL --------------------------------------------------------------- 15- 7

15-0

15. IGNITION SYSTEM

MX’er SYSTEM

CDI Unit/Change Gear Control.
l

Ignition Switch

Spark Plug

Ignition Coil
A.C. Generator/ Pulser Coil

IGNITION CIRCUIT

PULSER COIL

15-1

15. IGNITION SYSTEM

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
Hot type
Cold type

Spark plug
Spark plug gap
Ignition timing
Ignition coil resistance (20 )

CR8E

0.6 0.7mm
“F” mark
Full advance
Primary coil
Secondary
with plug cap
coil
plug cap

Pulser coil resistance (20 )
Exciter coil resistance (20 )
Ignition coil primary side max. voltage
Pulser coil max. voltage

15ºBTDC/1,700±100rpm
0.2 0.3Ω
3.2 4.8KΩ
4.2 5.2KΩ
50 60Ω
100 120Ω
12V min.
2.1V min.

TESTING INSTRUMENT
Kowa Electric Tester
or commercially available electric tester with resistance over 10MΩ/CDV

15-2

15. IGNITION SYSTEM

MX’er SYSTEM

TROUBLESHOOTING
High voltage too low
• Weak battery or low engine speed
• Loose ignition system connection
• Faulty CDI unit
• Faulty ignition coil
• Faulty pulser coil
Normal high voltage but no spark at plug
• 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

No high voltage
• Faulty ignition switch
• Faulty CDI unit
• Poorly connected or broken CDI ground wire
•Dead battery or faulty regulator/rectifier
• Faulty ignition coil connector
• Faulty pulser coil

CDI UNIT INSPECTION
Remove the seat.
Disconnect the CDI coupler and remove the

15-3

15. IGNITION SYSTEM

MX’er SYSTEM

CDI unit.
Measure the resistance between the
terminals using the electric 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.

CDI Unit
Black/White

Testing Range
Use the xKΩ range for the Sanwa Tester.
Use the xKΩ range for the Kowa Tester.

Black/Red

Black/Yellow

Blue/Yellow

Green/Red

Green/White

Unit: KΩ
Probe⊕

Black/
White

Black/
Red

Blue/
White

Green

Green/
White

Black/
Yellow

(-)Probe

Black/
White

∞

Needle
Swings then

∞

Needle
Swings then

∞

8-10K

∞

There is
continuity

∞

Black/
Red

3-6K

Blue/
White

35-42K

18-22K

Green

15-18K

4.5-5.5K

7-9K

Green/
White

15-18K

4.5-5.5K

8-9K

Black/

∞
∞
∞
Note: The readings in this table are taken
with a Sanwa Tester.

Change Gear Control

There is
continuity
∞

∞
∞

Test the CDI unit using the CDI tester.
Operate the CDI tester by following the
manufacturer‘s instructions.

15-4

CDI Tester

Ignition Coil

15. IGNITION SYSTEM

MX’er SYSTEMSpark
Window

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
No spark
No spark
Good spark
Good spark

⎯⎯
⎯⎯
Good spark
No spark
No spark

CDI Unit

Spark Plug

If the CDI unit is faulty, replace it with a
new one.
Blue/Yellow

Yellow/Brown

Light Green/Red

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.
Green/
Black
Green
Yellow
Probe⊕

Green /Pink

Black

Green

Green /Yellow

Unit:
KΩ
Green/
Pink

Light Green/ Blue/
Red
Yellow

Yellow/
Brown

(-)Probe

Black
Green

5-50K
∞

5-50K

10-50K

5-50K

∞

Green/
∞
5-50K
Yellow
Green/
∞
∞
∞
Pink
Light Green/
∞
∞
∞
Red
Blue/
∞
50-200K 50-200K
Yellow
Yellow/
∞
0
5-50K
B
Note: The readings in this table are taken
with a Sanwa Tester.

0
50-200K

50-200K

5-50K

IGNITION COIL INSPECTION
CONTINUITY TEST

15-5

15. IGNITION SYSTEM

MX’er SYSTEM

Remove the front cover.
Remove the spark plug cap.
Disconnect the ignition coil wires.
This test is to inspect the continuity of
ignition coil.
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
This test is for reference only. Accurate
test should be performed with a CDI
tester.

Measure the spark plug cap resistance.
Remove the spark plug cap and measure the
spark plug resistance.
Resistance: 4.2 5.2KΩ/20
Measure the resistance in the XKΩ range
of the electric tester.

PERFORMANCE TEST
Test the performance with a CDI tester.
• Operate the CDI tester by following
the manufacturer‘s instructions.
• Use the special connector to connect
the CDI unit.
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.

Ignition Coil

PULSER COIL
INSPECTION

15-6

15. IGNITION 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

15-7

MX’er SYSTEM

16. STARTING SYSTEM

MX’er SYSTEM

16
__________________________________________________________________________________

____________________________________________________________________

STARTING SYSTEM
____________________________________________________________________

SERVICE INFORMATION------------------------------------------------ 16- 2
TROUBLESHOOTING----------------------------------------------------- 16- 2
STARTER MOTOR --------------------------------------------------------- 16- 3
STARTER RELAY---------------------------------------------------------- 16- 5

16-0

16. STARTING SYSTEM

MX’er SYSTEM

Stop Switches

Starter Button

Ignition
S it h
Fuse/Battery/Starter Relay

Starter Motor

STARTING CIRCUIT

16-1

16. STARTING SYSTEM

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
• Fuse burned out
• Weak battery
• Faulty ignition switch
• Faulty starter clutch
• Faulty front or rear stop switch
• Faulty starter relay
• Poorly connected, broken or shorted wire
• Faulty starter motor

Lack of power
• Weak battery
• Loose wire or connection
• Foreign matter stuck in starter motor
or gear
Starter motor rotates but engine does
not start
• Faulty starter clutch
• Starter motor rotates reversely
• Weak battery

16-2

16. STARTING SYSTEM

MX’er SYSTEM

STARTER MOTOR
REMOVAL
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.
Remove the two starter motor mounting
bolts and the motor.
Remove the waterproof rubber jacket and
disconnect the starter motor cable
connector.

Starter Motor Cable

Front Cover

DISASSEMBLY
Remove the two starter motor case screws,
front cover, motor case and other parts.

Case Screws
Commutator

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.

Bolts

16-3

Motor Case

16. STARTING SYSTEM

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.

Wire Terminal

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.

Bearing

Dust Seal

16-4

16. STARTING SYSTEM

MX’er SYSTEM
Commutator

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.
• 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.

Front Cover
Tab

Groove

O-ring

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.
When assembling the front cover and
motor case, slightly press down the
armature shaft to assemble them.
Motor Case
Starter Relay

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.

16-5

16. STARTING SYSTEM

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.
The starter motor cable connector must
be installed properly.

O-ring

16-6

17. LIGHTS/ SWITCHES

MX’er SYSTEM

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

17-0

17. LIGHTS/ SWITCHES

MX’er SYSTEM

ELECTRICAL EQUIPMENT LAYOUT

Stop Switches

Headlight Switch/
Starter Button

Ignition Switch
Taillight/Stop Light

Headlight

17-1

17. LIGHTS/ SWITCHES

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
when ignition switch is “ON”
• Faulty ignition switch
• Fuse burned out
• Weak battery
• Burned bulb
• Faulty switch
• Poorly connected, broken or shorted wire

Engine starts but stalls during idling
• Clogged carburetor

17-2

17. LIGHTS/ SWITCHES
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.

MX’er SYSTEM

Cover

Bolts

Remove the two headlight case attaching
screws and disconnect the headlight.

Screws

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.

17-3

Headlight Wire Coupler

Rubber Boot

Screws

17. LIGHTS/ SWITCHES

MX’er SYSTEM

Headlight Bulb

Remove the headlight bulb
INSTALLATION
Install the headlight in the reverse order of
removal.
After installation, adjust the headlight
beam.

INSTRUMENTS

Light Shell

Bulb Socket

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.

Rubber Boot

INSTALLATION
The installation sequence is the reverse of
removal.

Taillight Shell

STOP LIGHT/TAILLIGHT
Remove the two taillight shell screws and
the shell.

Taillight Shell Screws

17-4

17. LIGHTS/ SWITCHES

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 Black
Position

Red

OFF
ON

○

Black/
White
○

Green
○

○

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.

17-5

Bulb

17. LIGHTS/ SWITCHES

MX’er SYSTEM

Yellow/Brown

STARTER BUTTON

Yellow/ Red

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

Starter Button
White

Black

Brown

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

○
○

Headlight Switch

Blue

Engine Stop Switch

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

○

○
Green

Green/Red

17-6

17. LIGHTS/ SWITCHES

17-7

MX’er SYSTEM

18. ONLY ATV ON ROAD AVAILABLE

MX’er SYSTEM

18
__________________________________________________________________________________

____________________________________________________________________

ONLY ATV ON ROAD AVAILABLE

____________________________________________________________________

WARING DIAGRAM ------------------------------------------------------ 18- 1
BRAKE PEDAL ADJUSTMENT ----------------------------------------- 18- 2
INSTRUMENT -------------------------------------------------------------- 18- 3
INDICATOR LIGHT-------------------------------------------------------- 18- 3
HAZARD SWITCH --------------------------------------------------------- 18- 4
HORN ------------------------------------------------------------------------- 18- 4

18-0

18. ONLY ATV ON ROAD AVAILABLE
WIRING DIAGRAM

18-1

MX’er SYSTEM

18. ONLY ATV ON ROAD AVAILABLE
BRAKE PEDAL ADJUSTMENT

MX’er SYSTEM

Brake Pedal

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:
10~20mm

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.

Front lower brake cable

Brake Cam Lever

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.

Lock Nut

Adjusting Bolt
Adjusting Nut

18-2

18. ONLY ATV ON ROAD AVAILABLE

MX’er SYSTEM

INSTRUMENT
REMOVAL
Remove the two instrument attaching
screws.
Disconnect the instrument.

Screws
Battery Cover

Remove battery cover on instrument back to
replace battery.
After replace battery, the instrument will
be reset. (Refer to owner’s manual)

Speed Wheel

SENSOR WHEEL
If the sensor is lost or wore, the speed will
be not calculated on the instrument.

Screw

INDICATOR LIGHT
REMOVAL
Remove the screw and disconnect the cover
of the ignition switch.

18-3

18. ONLY ATV ON ROAD AVAILABLE
Remove the bulb socket and bulb.
Check the bulb for damage and replace with
a new one if necessary.

MX’er SYSTEM

Bulb Socket

INSTALLATION
The installation sequence is the reverse of
removal.

Bulb

HAZARD SWITCH
Check for continuity between the wires
indicated below.
Color Yellow
/Black
Position

○

Black
○

●

Hazard Switch

HORN
REMOVAL
Disconnect the horn switch wire.
Remove the bolt and remove horn.

INSTALLATION
The installation sequence is the reverse of
removal.
Bolt

Horn Switch wire

18-4

18. ONLY ATV ON ROAD AVAILABLE

18-5

MX’er SYSTEM

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PDF Version                     : 1.6
Linearized                      : Yes
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XMP Toolkit                     : 3.1-701
Modify Date                     : 2005:11:28 14:57:54+01:00
Create Date                     : 2005:11:28 14:57:54+01:00
Metadata Date                   : 2005:11:28 14:57:54+01:00
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Format                          : application/pdf
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Producer                        : Acrobat Distiller 7.0 (Windows)
Page Count                      : 181
Author                          : yu

EXIF Metadata provided by EXIF.tools

Kymco MXER 125 150 Service Manual

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