SYM Quad Lander 250 User Manual

HOW TO USE THIS MANUAL

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CONTENTS

SERIAL NUMBER

Quad Lander 250

SERVICE MANUAL

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This service manual contains the technical data of each component inspection and
repair for the SANYANG Quad Lander 250 ATV. The manual is shown with
illustrations and focused on “Service Procedures”, “Operation Key Points”, and
“Inspection Adjustment” so that provides technician with service guidelines.

If the style and construction of the ATV, Quad Lander 250, are different from that
of the photos, pictures shown in this manual, the actual vehicle shall prevail.
Specifications are subject to change without notice.

Service Department

SANYANG INDUSTRY CO., LTD.

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Contents

HOW TO USE THIS MANUAL

This service manual describes basic information of different system parts and
system inspection & service for SANYANG Quad Lander 250 ATV. In addition,
please refer to the manual contents in detailed for the model you serviced in
inspection and adjustment.

The first chapter covers general information and trouble diagnosis.
The second chapter covers service maintenance information and special tools
manual.
The third to the 11th chapters cover engine and driving systems.
The 12th chapter is cooling system.
The 13th to the 16th chapter is contained the parts set of assembly frame body.
The 17th chapter is electrical equipment.
The 18th chapter is wiring diagram.
Please see index of content for quick having the special parts and system
information.

There are 4 buttons, “Forward”, “Contents”, “How to use this manual” and
“Mechanism Illustrations” on the CD-R version, and can be access to these items
by click the mouse.

If user wants to look for the content of each chapter, selecting the words of each
chapter on the contents can reach to each chapter. There are two buttons,
“Homepage and contents, onto the top line of first page of the each chapter. Thus,
if the user needs to check other chapters, he can click the top buttons to back the
homepage or contents. The content of each chapter can be selected too.
Therefore, when needs to checking the content inside of the chapter, click the
content words of the chapter so that can back to the initial section of the content.
In addition, there is a “To this chapter contents” button at the second page of each
contents so that clicking the button can back to the contents of this chapter.

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Page Content Index

1-1 ~ 1-18
2-1 ~ 2-14
3-1 ~ 3-8
4-1 ~ 4-12
5-1 ~ 5-6
6-1 ~ 6-16

7-1 ~ 7-8

GENERAL INFORMATION
SERVICE MAINTENANCE INFORMATION
LUBRICATION SYSTEM
FUEL SYSTEM
ENGINE REMOVAL
CYLINDER HEAD/VALVE

CYLINDER/PISTON

CONTENTS

1
2
3
4
5
6

7

8-1 ~ 8-14

9-1 ~ 9-12
10-1 ~ 10-10
11-1 ~ 11-8
12-1 ~ 12-12
13-1 ~ 13-14
14-1 ~ 14-14

15-1 ~ 15-10
16-1 ~ 16-18

17-1 ~ 17-22

“V” TYPE BELT DRIVING SYSTEM/KICK-STARTER

FINAL DRIVING MECHANISM
ALTERNATOR
CRANKSHAFT/ CRANKCASE
COOLING SYSTEM
BODY COVER
FRONT BRAKE AND FRONT WHEEL

STEERING/FRONT SUSPENSION

REAR BRAKE/REAR WHEEL/REAR CUSHION
ELECTRICAL EQUIPMENT

8

9
10
11
12
13
14

15
16

17

18-1 ~ 18-2

ELECTRICAL DIAGRAM

18

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Contents

SERIAL NUMBER

Frame number

Engine number

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Contents

Symbols and Marks............................. 1-1

General Safety..................................... 1-2

Service Precautions............................ 1-3

Specifications......................................1-9

Specifications..................................... 1-10

Torque Values.................................... 1-11

Troubles Diagnosis............................ 1-13

Lubrication Points ............................. 1-18

1. GENERAL INFORMATION

Symbols and Marks

Symbols and marks are used in this manual to indicate what and where the special service are needed, in
case supplemental information is procedures needed for these symbols and marks, explanations will be
added to the text instead of using the symbols or marks.

Warning

Caution

Engine oil

Means that serious injury or even death may result if procedures are not
followed.

Means that equipment damages may result if procedures are not followed.
Limits to use SAE 10W-30 API SG class oil. Warranty will not cover the

damage that caused by not apply with the limited engine oil.
(Recommended oil: KING MATE G-3 oil)

1

Grease King Mate G-3 is recommended.

King Mate gear oil serials are recommended. (Bramax HYPOID GEAR OIL

Gear oil

Locking sealant

Oil seal

Renew

Brake fluid

Special tools

Correct

Wrong

Indication Indication of components.

# 140)
Apply sealant; medium strength sealant should be used unless otherwise
specified.

Apply with lubricant.。

Replace with a new part before installation.

Use recommended brake fluid DOT3 or WELLRUN brake fluid.

Special tools

Meaning correct installation.

Meaning wrong installation.

Directions

Indicates position and operation directions

Components assembly directions each other.
Indicates where the bolt installation direction, --- means that bolt cross

through the component (invisibility).

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To this chapter contents

1. GENERAL INFORMATION

General Safety

Carbon monoxide

If you must run your engine, ensure the place is
well ventilated. Never run your engine in a closed
area. Run your engine in an open area, if you
have to run your engine in a closed area, be sure
to use an extractor.

Caution

Exhaust contains toxic gas which may cause one
to lose consciousness and even result in death.

Gasoline

Gasoline is a low ignition point and explosive
material. Work in a well-ventilated place, no flame
or spark should be allowed in the work place or
where gasoline is being stored.

Caution

Gasoline is highly flammable, and may explode
under some conditions, keep it away from
children.

Used engine oil

Caution

Prolonged contact with used engine oil (or
transmission oil) may cause skin cancer although
it might not be verified.
We recommend that you wash your hands with
soap and water right after contacting. Keep the
used oil beyond reach of children.

Hot components

Caution

Components of the engine and exhaust system
can become extremely hot after engine running.
They remain very hot even after the engine has
been stopped for some time. When performing
service work on these parts, wear insulated
gloves and wait until cooling off.

Battery

Caution

• Battery emits explosive gases; flame is strictly
prohibited. Keeps the place well ventilated
when charging the battery.

• Battery contains sulfuric acid (electrolyte)
which can cause serious burns so be careful
do not be spray on your eyes or skin. If you
get battery acid on your skin, flush it off
immediately with water. If you get battery acid
in your eyes, flush it off immediately with
water and then go to hospital to see an
ophthalmologist.

• If you swallow it by mistake, drink a lot of

water or milk, and take some laxative such as
castor oil or vegetable oil and then go to see a
doctor.

• Keep electrolyte beyond reach of children.

Brake shoe

Do not use an air hose or a dry brush to clean
components of the brake system; use a vacuum
cleaner or the equivalent to avoid dust flying.

Caution

Inhaling brake shoe or pad ash may cause
disorders and cancer of the breathing system

Brake fluid

Caution

Spilling brake fluid on painted, plastic, or rubber
parts may cause damage to the parts. Place a
clean towel on the above-mentioned parts for
protection when servicing the brake system.
Keep the brake fluid beyond reach of children.

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Service Precautions

y Always use with SANYANG genuine parts and

recommended oils. Using non-designed parts
for SANYANG ATV may damage the ATV.

y Special tools are designed for remove and

install of components without damaging the
parts being worked on. Using wrong tools may
result in parts damaged.

y When servicing this ATV, use only metric tools.

Metric bolts, nuts, and screws are not
interchangeable with the English system, using
wrong tools and fasteners may damage this
vehicle.

1. GENERAL INFORMATION

y Never bend or twist a control cable to prevent

unsmooth control and premature worn out.

y Rubber parts may become deteriorated when

old, and prone to be damaged by solvent and oil.
Check these parts before installation to make
sure that they are in good condition, replace if
necessary.

y When loosening a component which has

different sized fasteners, operate with a
diagonal pattern and work from inside out.
Loosen the small fasteners first. If the bigger
ones are loosen first, small fasteners may
receive too much stress.

y Store complex components such as

transmission parts in the proper assemble order
and tie them together with a wire for ease of
installation later.

y Clean the outside of the parts or the cover

before removing it from the ATV. Otherwise, dirt
and deposit accumulated on the part's surface
may fall into the engine, chassis, or brake
system to cause damage.

y Wash and clean parts with high ignition point

solvent, and blow dry with compressed air. Pay
special attention to O-rings or oil seals because
most cleaning agents have an adverse effect on
them.

y Note the reassemble position of the important

components before disassembling them to
ensure they will be reassembled in correct
dimensions (depth, distance or position).

y Components not to be reused should be

replaced when disassembled including gaskets
metal seal rings, O-rings, oil seals, snap rings,
and split pins.

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1. GENERAL INFORMATION

y The length of bolts and screws for assemblies,

cover plates or boxes is different from one
another, be sure they are correctly installed. In
case of confusion, Insert the bolt into the hole to
compare its length with other bolts, if its length
out side the hole is the same with other bolts, it
is a correct bolt. Bolts for the same assembly
should have the same length.

y Tighten assemblies with different dimension

fasteners as follows: Tighten all the fasteners
with fingers, then tighten the big ones with
special tool first diagonally from inside toward
outside, important components should be
tightened 2 to 3 times with appropriate
increments to avoid warp unless otherwise
indicated. Bolts and fasteners should be kept
clean and dry. Do not apply oil to the threads.

y Remove residues of the old gasket or sealant

before reinstallation, grind with a grindstone if
the contact surface has any damage.

y The ends of rubber hoses (for fuel, vacuum, or

coolant) should be pushed as far as they can go
to their connections so that there is enough
room below the enlarged ends for tightening the
clamps.

Groove

Clamp

Connector

y Rubber and plastic boots should be properly

reinstalled to the original correct positions as
designed.

y When oil seal is installed, fill the groove with

grease, install the oil seal with the name of the
manufacturer facing outside, and check the
shaft on which the oil seal is to be installed for
smoothness and for burrs that may damage the
oil seal.

Manufacturer's name

1-4

Boots

y The tool should be pressed against two (inner

and outer) bearing races when removing a ball
bearing. Damage may result if the tool is
pressed against only one race (either inner race
or outer race). In this case, the bearing should
be replaced. To avoid damaging the bearing,
use equal force on both races.

Both of these examples can result in
bearing damage.

To this chapter contents

y Lubricate the rotation face with specified

lubricant on the lubrication points before
assembling.

y Check if positions and operation for installed

parts is in correct and properly.

y Make sure service safety each other when

conducting by two persons.

1. GENERAL INFORMATION

y After service completed, make sure all

connection points is secured.
Battery positive (+) cable should be connected
firstly.

y And the two posts of battery have to be greased

after connected the cables.

y Make sure that the battery post caps are

located in properly after the battery posts had
been serviced.

y Note that do not let parts fall down.

y Before battery removal operation, it has to

remove the battery negative (-) cable firstly.
Notre tools like open-end wrench do not contact
with body to prevent from circuit short and
create spark.

y If fuse burned, it has to find out the cause and

solved it. And then replace with specified
capacity fuse.

Capacity
verification

1-5

To this chapter contents

1. GENERAL INFORMATION

y When separating a connector, it locker has to

be unlocked firstly. Then, conduct the service
operation.

y Do not pull the wires as removing a connector

or wires. Hold the connector body.

y Make sure if the connector pins are bent,

extruded or loosen.

y Insert the terminal completely.

Check if the terminal is covered by the boot.
Do not let boot open facing up.

y Secure wires and wire harnesses to the frame

with respective wire bands at the designated
locations. Tighten the bands so that only the
insulated surfaces contact the wires or wire
harnesses.

y Insert the connector completely.

If there are two lockers on two connector sides,
make sure the lockers are locked in properly.
Check if any wire loose.

y Check if the connector is covered by the twin

connector boot completely and secured
properly.

y Wire band and wire harness have to be

clamped secured properly.

y Do not squeeze wires against the weld or its

clamp.

y Before terminal connection, check if the boot is

crack or the terminal is loose.

1-6

To this chapter contents

y Do not let the wire harness contact with rotating,

moving or vibrating components as routing the
harness.

y Keep wire harnesses far away from the hot

parts.

Never Touch

1. GENERAL INFORMATION

y Protect wires or wire harnesses with electrical

tape or tube if they contact a sharp edge or
corner. Thoroughly clean the surface where
tape is to be applied.

y Secure the rubber boot firmly as applying it on

wire harness.

y Route wire harnesses to avoid sharp edges or

corners and also avoid the projected ends of
bolts and screws.

y Route harnesses so that they neither pull too

tight nor have excessive slack.

y Never use wires or harnesses which insulation

has been broken. Wrap electrical tape around
the damaged parts or replace them.

y Never clamp or squeeze the wire harness as

installing other components.

Never clamp or
squeeze the wire
harness

Never too tight

1-7

To this chapter contents

1. GENERAL INFORMATION

y Do not let the wire harness been twisted as

installation.

y Wire harnesses routed along the handlebar

should not be pulled too tight or have excessive
slack, be rubbed against or interfere with
adjacent or surrounding parts in all steering
positions.

y With sand paper to clean rust on connector

pins/terminals if found. And then conduct
connection operation later.

Clean rust

y Before operating a test instrument, operator

should read the operation manual of the
instrument. And then, conduct test in
accordance with the instruction.

Do you know how to set the
instrument to its
measurement position and
the insert locations of its
two probes?

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To this chapter contents

Specifications

MAKER SANYANG MODEL UA25A

Overall Length 1890 mm Front Double arm

Overall Width 1055 mm

Overall Height 1115 mm Front AT22x7-10 (off road)

Wheel Base 1200 mm

Dimension

Wheel tread

Curb Weight

Passengers/Weight Two /150 kg

Weight

Total Weight

Type 4-Stroke Engine Clutch Centrifugal, dry type

Installation and

arrangement

1. GENERAL INFORMATION

Suspension

System

Tire Specifications

Front 810 mm Rim Aluminum

Rear 805 mm Front Disk (ψ175mm)

Front 109 kg

Rear 114 kg Max. Speed Above 80 km/hr

Total 223 kg

Front 142 kg

Rear 231 kg

Total 373 kg

Vertical, below center,

incline

Brake System

Performance

Climb Ability Below 25°

Reduction

Transmission

Rear Unit Swing

Rear AT22x10-9 (off road)

Rear Disk (ψ220mm)

Primary

Reduction

Secondary

Reduction

C.V.T., auto speed

Belt

Gear / Sprocket

change

Fuel Used Above 92 unleaded Speedometer 0 ~ 100 km/hr

Cycle/Cooling 4-stroke/water cooled Horn 93~112 dB/A

Bore Ø71 mm Muffler

Stroke 63 mm

Cylinder

Number/Arrange

Engine

Displacement 249.4 cc Solid Particulate

Compression Ratio 10.5 : 1 CO Below 7.0 g/ km

Max. Torque 20.6Nm / 5500rpm

Starting System Electrical starter P.C.V. ─

ment

Max. HP 13.2kw / 7000rpm HC Below 1.5g/ km

Ignition C.D.I. E.E.C. ─

Air filtration Sponge

Single Cylinder Lubrication System

Exhaust Pipe Position and

Direction

Exhaust

Concentration

Catalytic reaction control

Nox Below 0.4g/ km

system

Expansion & Pulse

Type

Left side, and

Backward

Forced circulation &

splashing

─

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To this chapter contents

1. GENERAL INFORMATION

Specifications

MAKER SANYANG MODEL UA25A1

Overall Length 1890 mm Front Double arm

Overall Width 1055 mm

Overall Height 1115 mm Front AT22x7-10 (on road)

Wheel Base 1200 mm

Dimension

Wheel tread

Curb Weight

Passengers/Weight Two /150 kg

Weight

Total Weight

Type 4-Stroke Engine Clutch Centrifugal, dry type

Installation and

arrangement

Front 810 mm Rim Aluminum

Rear 805 mm Front Disk (ψ175mm)

Front 109 kg

Rear 114 kg Max. Speed Above 80 km/hr

Total 223 kg

Front 142 kg

Rear 231 kg

Total 373 kg

Vertical, below center,

incline

Suspension

System

Tire Specifications

Brake System

Performance

Climb Ability Below 25°

Reduction

Secondary

Reduction

Reduction

Transmission

Rear Unit Swing

Rear AT22x10-9 (on road)

Rear Disk (ψ220mm)

Primary

C.V.T., auto speed

Belt

Gear / Sprocket

change

Fuel Used Above 92 unleaded Speedometer 0 ~ 100 km/hr

Cycle/Cooling 4-stroke/water cooled Horn 93~112 dB/A

Bore Ø71 mm Muffler

Stroke 63 mm

Cylinder

Number/Arrange

Engine

Displacement 249.4 cc Solid Particulate

Compression Ratio 10.5 : 1 CO Below 7.0 g/ km

Max. Torque 20.6Nm / 5500rpm

Starting System Electrical starter P.C.V. ─

ment

Max. HP 13.2kw / 7000rpm HC Below 1.5g/ km

Ignition C.D.I. E.E.C. ─

Air filtration Sponge

Single Cylinder Lubrication System

Exhaust Pipe Position and

Direction

Exhaust

Concentration

Catalytic reaction control

Nox Below 0.4g/ km

system

Expansion & Pulse

Type

Left side, and

Backward

Forced circulation &

splashing

─

1-10

To this chapter contents

1. GENERAL INFORMATION

Torque Values

The torque values listed in above table are for more important tighten torque values. Please see standard
values for not listed in the table.

Standard Torque Values for Reference

Type Tighten Torque Type Tighten Torque

5 mm bolt、nut
6 mm bolt、nut
8 mm bolt、nut
10 mm bolt、nut
12 mm bolt、nut

Engine Torque Values

Item Q’ty Thread Dia. (mm) Torque Value(kgf-m) Remarks

Cylinder stud bolt 4 10 1.0~1.4
Cylinder head nut 4 8 3.6~4.0
Cylinder head right bolt 2 8 2.0~2.4
Cylinder head side cover bolt 2 6 1.0~1.4
Cylinder head cover bolt 4 6 1.0~1.4
Cylinder head stud bolt (inlet pipe) 2 6 1.0~1.4
Cylinder head stud bolt (EX. pipe) 2 8 2.4~3.0
Air inject pipe bolt 4 6 1.0~1.4
Air inject reed valve bolt 2 3 0.07~0.09
Tappet adjustment screw nut 4 5 0.7~1.1 Apply oil to thread
Spark plug 1 10 1.0~1.2
Tensioner lifter bolt 2 6 1.0~1.4
Carburetor insulator bolt 2 6 0.7~1.1
Oil pump screw 2 3 0.1~0.3
Water pump impeller 1 7 1.0~1.4
Engine left cover bolt 9 6 1.1~1.5
Engine oil draining bolt 1 12 3.5~4.5
Engine oil strainer cap 1 30 1.3~1.7
Mission draining bolt 1 8 1.1~1.5
Mission filling bolt 1 12 3.5~4.5
Shift drum fixing bolt 1 14 3.5~4.5
Clutch driving plate nut 1 28 5.0~6.0
Clutch outer nut 1 14 5.0~6.0
Drive face nut 1 14 8.5~10.5
ACG. Flywheel nut 1 14 5.0~6.0
Crankcase bolts 7 6 0.8~1.2
Mission case bolt 7 8 2.6~3.0

0.45~0.6kgf-m 5 mm screw 0.35~0.5kgf-m

0.8~1.2kgf-m

1.8~2.5kgf-m

3.0~4.0kgf-m

5.0~6.0kgf-m

6 mm screw、SH nut
6 mm bolt、nut
8 mm bolt、nut
10 mm bolt、nut

0.7~ 1.1kgf-m

1.0 ~1.4kgf-m

2.4 ~3.0kgf-m

3.5~4.5kgf-m

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1. GENERAL INFORMATION

Frame Torque Values

Item Q’ty Thread Dia. (mm) Torque Value(kgf-m) Remarks

Handlebar upper holder bolt
Steering shaft nut
Steering tie-rod nut
Knuckle nut
Steering shaft holder bolt
Tie rod lock nut
Handlebar under holder nut
Front wheel nut
Front axle castle nut
Rear axle castle nut
Rear wheel nut
Engine hanger nut
Rear axle holder bolt
Drive gear bolt
Driven gear nut
Swing arm pivot bolt

Front suspension arm nut 4 10 5.00
Front / Rear cushion mounting bolt 6 10 4.60

Brake lever nut
Brake hose bolt
Brake caliper bolt
Brake disk mounting bolt
Air-bleed valve
Exhaust muffler mounting bolt
Exhaust muffler connection nut

4 6 2.40
1 10 5.00
4 10 5.00
2 10 5.00
2 8 3.40
4 10 3.60
2 8 4.00
8 10 2.40
2 14 5.00
2 14 5.00
8 10 2.40
4 12 8.50
4 12 9.20
2 10 4.6
4 10 4.6
1 14 9.20

2 6 1.00

13 10 3.50

6 6 3.25

11 8 4.25

3 5 0.50
2 8 3.00
2 7 1.20

1-12

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To this chapter contents

1. GENERAL INFORMATION

Troubles Diagnosis

A. Engine hard to start or can not be started

Check and adjustment Fault condition Probable causes

Loosen carburetor drain bolt to
check if there is gasoline inside
the carburetor

Fuel supplied tom
carburetor sufficient

Remove spark plug, install it
into spark plug cap, and perform
a spark test against engine

round.

Check if sparks Weak sparks, no spark at

Perform cylinder compression
pressure test.

No fuel is supplied to
carburetor

all

y No fuel in fuel tank
y Check if the pipes, fuel tank to carburetor

and intake vacuum, are clogged.

y Float valve clogged
y Lines in fuel tank evaporation system

clogged

y Malfunction of fuel pump
y Loosen or damaged fuel pump vacuum

hose

y Fuel filter clogged

y Malfunction of spark plug
y Spark plug foul
y Malfunction of CDI set
y Malfunction of AC generator
y Ignition coil is in open or short circuit
y Ignition coil leads open or short circuit
y Malfunction of main switch

Cylinder compression
pressure normal

Re-start by following the starting
procedures

No ignition T here are some signs of

Remove the spark plug again
and check it.

Dry spark plug Wet spark plug

Remove carburetor after 30
minutes and connect a hose
onto fuel rich circuit. Then blow
the hose with air

Low compression
pressure or no pressure

ignition; nut engine can

y Piston ring seized
y Malfunction of cylinder valves
y Worn cylinder and piston ring
y Cylinder gasket leak
y Sand hole in compression parts

y Malfunction of throttle valve operation
y Air sucked into intake manifold
y Incorrect ignition timing

y Fuel level in carburetor too high
y Malfunction of throttle valve operation
y Throttle valve opening too wide

Blowing in normal Blowing clogged

y Malfunction of automatic by- starter

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1. GENERAL INFORMATION

B. Engine run sluggish (Speed does not pick up, lack of power)

Check and adjustment Fault condition Probable causes

Try gradual acceleration and
check engine speed

Engine speed can be
increased.

Check ignition timing (Using
ignition lamp)

Ignition timing correct Incorrect ignition timing

Check cylinder compression
pressure (using compression

Compression pressure
correct

Check if carburetor jet is
clogged

Engine speed can not be
increased.

No compression pressure

y Air cleaner clogged
y Poor fuel supply
y Lines in fuel tank evaporation system

clogged

y Exhaust pipe clogged
y Fuel nozzle clogged in carburetor.
y Fuel nozzle clogged in carburetor.

y Malfunction of CDI
y Malfunction of AC alternator

y Cylinder & piston ring worn out
y Cylinder gasket leaked
y Sand hole in compression parts
y Valve deterioration
y Seized piston ring

No clogged Clogged

Remove spark plug

No foul or discoloration Fouled and discoloration

Check if engine over heat

Normal Engine overheat

Continually drive in acceleration
or high speed

No knock Knock

y Remove foreign

y Remove dirt
y Incorrect spark plug heat range

y Piston and cylinder worn out
y Lean mixture
y Poor fuel quality
y Too much carbon deposited in

combustion chamber

y Ignition timing too advanced
y Poor circuit on the cooling system

y Too much carbon deposited in

combustion chamber

y Lean mixture
y Poor fuel quality
y Ignition timing too advanced

1-14

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1. GENERAL INFORMATION

C. Engine runs sluggish (especially in low speed and idling)

Check and adjustment Fault condition Probable causes

Check ignition timing (using
ignition lamp)

Normal

Adjust the air screw of
carburetor

Good Poor

Air sucked through carburetor
gasket

No air sucked Air sucked

Remove spark plug, install
spark plug into spark plug cap
and perform spark test against
engine ground

Good spark Poor

Abnormal

y Incorrect ignition timing (malfunction of

CDI or AC alternator)

y Rich mixture (loosen the screw)
y Lean mixture (tighten the screw)

y Poor heat insulation gasket
y Carburetor lock loose
y Poor intake gasket
y Poor carburetor O-ring
y Vacuum hose crack

y Spark plug fouled
y Malfunction of CDI
y Malfunction of AC generator
y Malfunction of ignition coil
y Open or short circuit in spark plug leads
y Malfunction of main switch

D. Engine runs sluggish (High speed)

Check and adjustment Fault condition

Check ignition timing

Check for fuel supplying system
in automatic fuel cup

Check if carburetor clogged

Normal Abnormal

Good Abnormal

No clogged Clogged

Probable causes

y Malfunction of CDI
y Malfunction of AC alternator

y Insufficient fuel in fuel tank
y Fuel filter clogged
y Restricted fuel tank vent

y Cleaning

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1. GENERAL INFORMATION

E. Clutch, driving and driving pulley

FAULT CONDITIONS

Engine can be started but
motorcycle can not be moved.

Engine running and misfire as
motorcycle initial forward moving or
jumping suddenly (rear wheel
rotating as engine in running)

Poor initial driving (Poor climbing
performance)

PROBABLE CAUSES

y Drive belt worn out or deformation
y Ramp plate of movable drive face damaged
y Driving pulley spring broken
y Clutch weights broken
y Drive slide-shaft gear groove broken
y Transmission gear damaged

y Clutch weights spring broken
y Clutch outer stuck with clutch weights
y Connection parts in clutch and shaft worn out or burned

y Drive belt worn out or deformation
y Weight roller worn out
y Movable drive face shaft worn out
y Driven pulley spring deformation
y Driven pulley shaft worn out
y Greased in drive belt and driven face.

F. Poor handling

Steering is heavy

One wheel is wobbling

Vehicle pulls to one side

FAULT CONDITIONS

PROBABLE CAUSES

y Damaged steering bearing
y Damaged steering shaft bushing

y Bent rim
y Improperly installed wheel hub
y Excessive wheel bearing play
y Bent swing arm
y Bent frame
y Swing arm pivot bushing excessively
y Worn

y Bent tie-rod
y Incorrect tie-rod adjustment
y Rear tie air pressure incorrect
y Improper wheel alignment
y Bent frame

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1. GENERAL INFORMATION

G. Loss power

Check and adjustment Fault condition Probable causes

Raise wheels off ground and
spin by hand

Spin freely

Check tire pressure

Normal Abnormal

Accelerate lightly, engine speed
can be increase

Normal Abnormal

Check ignition timing

Normal Abnormal

Test cylinder compression

Normal Abnormal

Check carburetor

Normal Clogged

Check spark plug

Normal Fouled or discolored

Check for engine overheating

Normal Overheating

Accelerate or run at high speed

Normal Knocks

Abnormal

y Brake dragging
y Drive chain too tight
y Damaged wheel bearing
y Wheel bearing needs lubrication

y Punctured tire
y Faulty tire valve

y Fuel / air mixture ratio too rich or lean
y Clogged in air cleaner
y Clogged in muffler
y Restricted fuel flow
y Clogged fuel tank cap breather hole

y Faulty pulse generator
y Faulty CDI unit

y Leaking head gasket
y Worn cylinder and piston rings

y Clean

y Clean the spark plug
y Spark plug is incorrect heat range

y Excessive carbon deposited in

combustion chamber

y Wrong type of fuel
y Fuel / air mixture ratio is lean
y Use of poor quality fuel

y worn piston and cylinder
y Fuel / air mixture ratio is lean
y Wrong type of fuel
y Ignition timing too advanced
y Excessive carbon deposited in

combustion chamber

1-17

To this chapter contents

1. GENERAL INFORMATION

Lubrication Points

Drive chain Acceleration cable/ Front & rear brake

lever pivot

1-18

Speedometer gear Wheel bearing

Home page

Contents

Precautions in Operation···················· 2-1
Periodical Maintenance Schedule······ 2-2
Fuel Lines············································· 2-3
Acceleration Operation ······················· 2-3
Air Cleaner············································ 2-3
Spark Plug············································ 2-3
Valve Clearance ··································· 2-4
Carburetor Idle Speed Adjustment····· 2-5
Ignition System···································· 2-6
Cylinder Compression Pressure ········ 2-6
Drive Belt·············································· 2-7

Precautions in Operation

2. MAINTENANCE INFORMATION

Drive Chain··········································· 2-7
Brake System (Disk Brake) ·················2-8
Brake Light Switch/Starting Inhibitor

Switch ··················································· 2-9
Headlight Beam Distance····················2-10
Clutch Disc Wear ·································2-10
Cushion················································· 2-10
Steering Handle···································· 2-11
Wheel/Tire·············································2-11
Nuts, Bolts Tightness·························· 2-11
Special Tools List ································2-12

2

Specification

Fuel Tank Capacity 12000 c.c.

Engine Oil

Transmission Gear oil

Capacity of coolant

Clearance of throttle valve 1~3 mm

Spark plug

“F” Mark in idling speed BTDC 10º / 1700 rpm

Full timing advanced BTDC 27º / 4000 rpm

Cylinder compression pressure 12.0 ±2 kgf/cm²

Capacity 1400 c.c.

Change 1200 c.c.

Capacity 750 c.c.

Change 650 c.c.

Engine + radiator 850 c.c.

Reservoir upper 420 c.c.

Type NGK CR8E

Gap 0.8 mm

Idling speed 1700±100 rpm

Valve clearance IN:0.10 ± 0.02 mm EX:0.15 ± 0.02 mm

Tire dimension

Tire pressure (cold) 3.8±2 psi

Battery 12V10Ah (MF battery) type: YTX12-BS

Front AT22x7-10

Rear AT22x10-9

2-1

To this chapter contents

2. MAINTENANCE INFORMATION

Periodical Maintenance Schedule

Maintenance

Code

1 Air cleaner
2 Fuel filter
3 Oil filter
4 Engine oil change
5 Tire pressure
6 Battery inspection
7 Brake & free ply check
8 Steering handle check

9 Cushion operation check
10 Every screw tightening check
11 Gear oil check for leaking
12 Spark plug check or change
13 Gear oil change
14 Frame lubrication
15 Exhaust pipe
16 Ignition timing
17 emission check in Idling
18 Throttle operation
19 Engine bolt tightening
20 CVT driving device(belt)
21 CVT driving device(roller)
22 Drive chain

23
24 Fuel lines

25 Cam chain
26 Valve clearance
27
28 Coolant reservoir
29 Coolant

Lights/electrical
equipment/multi-meters

Lines & connections in cooling

Item

Every

300KM

I / L I / L

1 Month

every

1,000KM

I C R

I I R
C C
R Replacement for every 1000 km

I I

I I

I I

I I

I I

I I

I I

I I R
R Replacement for every 5000 km

L

I I

I I
A I

I I

I I

I R

C

I I

I I

I I

I A

I I

I I

I I R

3 month

every

3,000KM

C

6 month

every

6000KM

1 year

every

12,000KM

15 month

every

14,500KM

Code: I ~ Inspection, cleaning, and adjustment R ~ Replacement

C ~ Cleaning (replaced if necessary) L ~ Lubrication

Have your ATV checked, adjusted, and recorded maintenance data periodically by your SYM Authorized Dealer to
maintain the ATV at the optimum condition
The above maintenance schedule is established by taking the monthly 1000 kilometers as a reference which ever
comes first.
Remarks: 1. Clean or replace the air cleaner element more often when the ATV is operated on dusty roads or in

the Heavily- polluted environment.

2. Maintenance should be performed more often if the ATV is frequently operated in high speed and
after the ATV has accumulated a higher mileage.

3. Preventive maintenance
a. Ignition system－Perform maintenance and check when continuous abnormal ignition, misfire,

after-burn, overheating occur.

b. Carbon deposit removal－Remove carbon deposits in cylinder head, piston heads, exhaust system

when power is obvious lower. Than ever

2-2

To this chapter contents

Fuel Lines

Remove the seat.

Loosen 2 screws and 2 bolts
Remove the tank cover

Check all lines, and replace it when they are
deterioration, damage or leaking

Warning

Gasoline is a low ignition material so any kind of
fire is strictly prohibited as dealing it.

Acceleration Operation

Have a wide open of throttle valve as handle in
any position and release it to let back original (full
closed) position.
Check handle if its operation is smooth.
Check acceleration cable and replace it if
deteriorated, twisted or damaged.
Lubricate the cable if operation is not smooth.
Measure the throttle lever free play in its flange
part.
Remove rubber boot, loosen fixing nut, and then
adjust it by turning the adjustment screw.
Tighten the fixing nut, and check acceleration
operation condition.

Free play: 1~3 mm.

Air Cleaner

Remove seat.
loosen 4 hooks from the air cleaner cover and
then remove the cover.
Loosen the clamp strip and 1 screw of air cleaner
element, and then remove the air cleaner element.
Clean the element with non-flammable or
high-flash point solvent and then squeeze it for
dry.

2. MAINTENANCE INFORMATION

Fuel tank

Fuel hose

Vacuum hose

Fuel filter

Lock nut

Throttle adjustment screw

Clamp

Element

Caution

Never use gasoline or acid organized solvent to
clean the element.

Soap the element into cleaning engine oil and then
squeeze it out. Install the element onto the
element seat and then install the air cleaner cover.

Spark Plug

Recommended spark plug: CR8E
Remove spark plug cap.
Clean dirt around the spark plug hole.
Remove spark plug.
Measure spark plug gap.

Spark plug gap：0.8 mm

Carefully bend ground electrode of the plug to
adjust the gap if necessary.
Hold spark plug washer and install the spark plug
by screwing it.
Tighten the plug by turning 1/2 turn more with plug
socket after installed.

Tighten torque: 1.0

~1.2kgf-m

Ground electrode

0.8~0.9mm

Central electrode

2-3

To this chapter contents

2. MAINTENANCE INFORMATION

Valve Clearance

Caution

Checks and adjustment must be performed when
the engine temperature is below 35℃.

Remove front fender, fuel tank cover and fuel tank.
Remove cylinder head cover.
Remove cylinder head side cover.
Turn camshaft bolt in C.W. direction and let the “T”
mark on the camshaft sprocket align with cylinder
head mark so that piston is placed at TDC position
in compression stroke.

Caution

Do not turn the bolt in C.C.W. direction to prevent
from camshaft bolt looseness.

Valve clearance inspection and adjustment.
Check & adjust valve clearance with feeler gauge.

Standard Value: IN 0.10 ± 0.02 mm

Timing mark

2 bolts

EX 0.15 ± 0.02 mm

Loosen fixing nut and turn the adjustment nut for
adjustment.

Caution

Re-check the valve clearance after tightened the
fixing nut.

2-4

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Carburetor Idle Speed Adjustment

Caution

y Inspection & adjustment for idle speed have to

be performed after all parts in engine that
needed adjustment have been adjusted.

y Idle speed check and adjustment have to be

done after engine is being warm up. (It is
enough that operates engine from stop to
running for 10 minutes.)

Park the ATV with main stand and warm up
engine.
Connect tachometer (the wire clamp of tachometer
is connected to the high tension cable).
Turn the throttle valve stopper screw to specified
idle speed.
Specified idle speed: 1700 ± 100 rpm

Emission adjustment in idle speed

Warm up the engine for around 10 minutes and
then conduct this adjustment.

1. Connect the tachometer onto engine.

2. Adjust the throttle valve stopper screw and let
engine runs in 1600±100 rpm.

3. Insert the exhaust sampling pipe of exhaust
analyzer into the front section of exhaust pipe.
Adjust the air adjustment screw so that
emission value in idle speed is within standard.

4. Slightly accelerate the throttle valve and
release it immediately. Repeat this for 2~3
times.

5. Read engine RPM and value on the exhaust
analyzer. Repeat step 2 to step 4 procedures
until measured value within standard.

Emission standard CO: below 2.5~3.5%

HC: below 2000ppm

2. MAINTENANCE INFORMATION

Ignition cable

Stopper screw

Air adjustment screw

2-5

To this chapter contents

2. MAINTENANCE INFORMATION

Ignition System

Caution

y C.D.I ignition system is set by manufacturer so

it can not be adjusted.

y Ignition timing check procedure is for checking

whether CDI function is in normal or not.

Connect tachometer and ignition light.
Start engine.
As engine in idle speed: 1600 rpm, aim at the
mark “F” with the ignition light. Then, it is means
that ignition timing is correct.
Increase engine speed to 6000 rpm to check
ignition advance degree. If indent is located within
the ignition advance degrees, it is means that the
ignition advance degree is in normal.
If ignition timing is incorrect, check CDI set, pulse
rotor and pulse generator. Replace it if
malfunction of these parts is found.

Cylinder Compression Pressure

Warm up engine.
Turn off the engine.
Remove the trunk.
Remove the central cover.
Remove spark plug cap and spark plug.
Install compression gauge.
Full open the throttle valve, and rotate the engine
by means of starter motor.

CDI unit

Caution

Rotate the engine until the reading in the gauge
no more increasing.
Usually, the highest pressure reading will be
obtained in 4~7 seconds.

Compression pressure: 12 ± 2 Kg/cm²

Check following items if the pressure is too low:

y Incorrect valve clearance.
y Valve leaking.
y Cylinder head leaking, piston, piston ring and

cylinder worn out.
If the pressure is too high, it means carbon
deposits in combustion chamber or piston head.

2-6

To this chapter contents

Drive Belt

Loosen the 2 clamp strips of left crankcase cover,
and then remove the left crankcase cover vapor
hose.
Remove 9 bolts of the engine left side cover and
the cover.

Check if the belt is crack or worn out.
Replace the belt if necessary or in accord with the
periodical maintenance schedule to replace it.

Width limit: 22.5 mm or above

Drive Chain

2. MAINTENANCE INFORMATION

Clamp strips

9 bolts

Teeth

Width

Check the drive chain

Park the ATV on a level ground, and shift the
transmission onto neutral.
Measure the drive chain slack midway between
the sprockets.

Chain slack: 15~25mm (5/8~1 inch)

Adjust the chain slack

Loosen the axle holder lock nuts and bolts
Loosen drive chain adjusting bolt lock nut and turn
drive chain adjusting bolt until get the correct
slack.
Tighten the axle holder nuts and bolts.

Torque: 3.25kgf-m

2 nuts

Lock nut

Adjustment bolt

2-7

To this chapter contents

2. MAINTENANCE INFORMATION

Brake System (Disk Brake)

Brake System Hose

Make sure the brake hoses for corrosion or
leaking oil.

Brake Fluid

Check brake fluid level in the brake fluid
reservoir. If the level is lower than the LOWER
limit, add brake fluid to UPPER limit. Also check
brake system for leaking if low brake level found

Caution

y In order to maintain brake fluid in the reservoir

in horizontal position, do not remove the cap

until handle stop.

y Do not operate the brake lever after the cap

had been removed. Otherwise, the brake fluid

will spread out if operated the lever.

y Do not mix non-compatible brake fluid together.

Filling Out Brake Fluid

Tighten the drain valve, and add brake fluid.
Operate the brake lever so that brake fluid
contents inside the brake system hoses.

Screws

Master cylinder cap

Air Bleed Operation

Connect a transparent hose to draining valve.
Hold the brake lever and open air bleeding valve.
Perform this operation alternative until there is no
air inside the brake system hoses.

Caution

Before closing the air bleed valve, do not release
the brake lever.

Added Brake Fluid

Add brake fluid to UPPER limit lever.
Recommended brake fluid: DOT3 or DOT4 WELL
RUN brake fluid.

Caution

Never mix or use dirty brake fluid to prevent from
damage brake system or reducing brake
performance.

Air bubble

Diaphragm plate

Diaphragm

Upper

Drain valve

Transparent hose

2-8

To this chapter contents

Brake Lining Wear

The indent mark on brake lining is the wear
limitation.
Replace the brake lining if the wear limit mark
closed to the edge of brake disc.

Caution

y To check front brake lining must be remove

front wheel first.

y It is not necessary to remove brake hose when

replacing the brake lining.

Brake Lining Replacement (refer chapter

14)

Make sure the brake lining condition. Replace
the lining if the brake lining wear limitation groove
close to the brake disc.

Caution

y Do not operate the brake lever after the clipper

removed to avoid clipping the brake lining.

y In order to maintain brake power balance, the

brake lining must be replaced with one set.

Brake Light Switch/Starting Inhibitor
Switch

The brake light switch is to light up brake light as
brake applied.
Make sure that electrical starter can be operated
only under brake applying.

2. MAINTENANCE INFORMATION

Front brake

Lining

Brake lining wear
limitation groove

Brake disk

Rear brake

Brake lining wear
limitation groove

Brake switch

Brake switch

2-9

To this chapter contents

2. MAINTENANCE INFORMATION

Headlight Beam Distance

Turn on main switch
Headlight beam adjustment. Turn the headlight
adjustment screw to adjust headlight beam high.

Caution

y To adjust the headlight beam follows related

regulations.

y Improper headlight beam adjustment will

make in coming driver dazzled or insufficient
lighting.

Clutch Disc Wear

Run the ATV and increase throttle valve opening
gradually to check clutch operation.
If the ATV is in forward moving and shaking, check
clutch disc condition. Replace it

Cushion

Adjust screw

Clutch weight

Drive plate

Warning

y Do not ride the ATV with poor cushion.
y Looseness, wear or damage cushion will make

poor stability and drive-ability.

Front cushion

Press down the front cushion for several times to
check it operation.
Check if it is damage
Replace relative parts if damage found.
Tighten all nuts and bolts.

Rear Cushion

Press down the rear cushion for several times to
check it operation.
Check if it is damage
Replace relative parts if damage found.

2-10

To this chapter contents

Steering Handle

Caution

Check all wires and cables if they are interfered
with the rotation of steering handle bar.

Lift the front wheel out of ground.
Turn handle from right to left alternative and check
if turning is smoothly.
If handle turning is uneven and bending, or the
handle can be operated in vertical direction, then
check the handle top bearing.

Wheel/Tire

Caution

Tire pressure check should be done as cold
engine.

2. MAINTENANCE INFORMATION

Check if tire surface is ticked with nails, stones or
other materials.

Appointed tire pressure

Tire size Front tire Rear tire

Tire pressure as cold

Check if front and rear tires’ pressure is in normal.
Measure tire thread depth from tire central surface.
Replace the tire if the depth is not come with
following specification:

Front tire: 1.5 mm
Rear tire: 2.0 mm

3.8±2

psi

Nuts, Bolts Tightness

Perform periodical maintenance in accord with the
Periodical Maintenance Schedule
Check if all bolts and nuts on the frame are
tightened securely.
Check all fixing pins, snap rings, hose clamp, and
wire holders for security.

2-11

To this chapter contents

2. MAINTENANCE INFORMATION

Special Tools List

NAME

NO SYM-1445100 NO SYM-9001200 NO SYM-1472100

Rocker arm pin puller

NAME

Tappet adjusting wrench

NAME

Tappet adjusting wrench

NAME

NO SYM-9001209 NO SYM-1471110/20 NO SYM-3110000-HMA

Tappet adjuster

NAME

Valve cotter remove &
assembly tool

NAME

AC.G. Flywheel puller

NAME

NO SYM-1332100-HMA NO SYM-2341110-HMA NO SYM-9120200-HMA

Left crank seal driver

NAME

Drive shaft puller

NAME

Driver shaft install bush & seal
driver

NAME

NO SYM-9100410/440 NO

Bearing driver 6205LLU

2-12

NAME

Rear axle bearing driver

SYM-9100100 RA1
A3017

NAME

NO SYM-9100200-HMA

Counter shaft needle bearing
drive HK1516

To this chapter contents

2. MAINTENANCE INFORMATION

NAME

NO SYM-9100300-RB1 NO SYM-2341110 NO SYM-9615000-RA1 6000

Counter shaft needle bearing
driver HK2016

NAME Bearing driver 6305 NAME

Left crank case cover bearing
driver 6000

NAME

NO SYM-9615000 NO SYM-9120600 RB1 RA1 NO SYM-9120100-RA1

Bearing driver 6205

NAME

(12*20*5)

NAME Water pump oil seal driver NAME Water pump bearing driver NAME

NO SYM-9120500-H9A NO SYM-9100100 NO SYM-1721700-H9A

Seal driver 14x28x7 &14x26x6

(6901)

NAME

Seal driver 30x40x5

Water pump mechanical
seal driver

(6301)

NAME

NO SYM-9610000 NO SYM-9110400 NO SYM-9020100

BEARING DRIVER

NAME

(6204)

BEARING DRIVER

NAME Lock nut driver

2-13

To this chapter contents

2. MAINTENANCE INFORMATION

NAME Inner bearing puller NAME Inner bearing puller NAME

NO SYM-6204002 NO SYM-6204022 NO SYM-6204001

Outer bearing puller

NAME Universal holder NAME Clutch nut wrench NAME Clutch spring compressor

NO SYM-2210100 NO SYM-9020200 NO SYM-2301000

(55mm)

NAME Rear axle nut wrench NAME

NO SYM-HT06007 NO SYM-HT07004-RA1 NO

Torque wrench

NAME

(55mm)

Rear axle nut torque wrench

SYM-4230200

NAME NAME NAME

NO NO NO

2-14

Home page

Contents

Mechanism Diagram······························3-1
Precautions in Operation······················ 3-2
Troubleshooting ····································3-2
Engine Oil···············································3-3

Mechanism Diagram

Press-In Lubrication

Oil Route

3. LUBRICATION SYSTEM

Engine Oil Strainer Clean······················3-3
Oil Pump·················································3-4
Gear Oil···················································3-7

Valve Rocker Arm

Cam Shaft

Spray Lubrication

3

Con-Rod

Spray Lubrication

Press-In Lubrication

Oil Route

Rotate Direction

Oil Pump

Oil Strainer

3-1

To this chapter contents

3. LUBRICATION SYSTEM

Precautions in Operation

General Information:

z This chapter contains maintenance operation

for the engine oil pump and gear oil

replacement.

Specifications

Engine oil quantity Disassembly: 1400 c.c.

Change: 1200c.c.

Oil viscosity SAE 10W-30 (Recommended

King serial oils)

Gear oil Disassembly: 750c.c.

Change: 650c.c.

Gear oil viscosity SAE 140
(Recommended SYM Hypoid gear oils)

單位:mm

Items Standard (mm) Limit (mm)

Inner rotor clearance 0.15 0.20

Oil pump

Clearance between outer rotor and body 0.15~0.20 0.25
Clearance between rotor side and body 0.04~0.09 0.12

Torque value

Torque value oil strainer cap 1.3~1.7kgf-m
Engine oil drain bolt 3.5~4.5kgf-m
Gear oil drain bolt 1.1~1.5kgf-m

Gear oil join bolt 3.5~4.5kgf-m
Oil pump connection screw 0.1~0.3kgf-m

Troubleshooting

Low engine oil level

y Oil leaking
y Valve guide or seat worn out
y Piston ring worn out

Low oil pressure

y Low engine oil level
y Clogged in oil strainer, circuits or pipes
y Oil pump damage

Dirty oil

y No oil change in periodical
y Cylinder head gasket damage
y Piston ring worn out

3-2

To this chapter contents

Engine Oil

Turn off engine, and park the ATV in flat surface
with main stand.
Check oil level with oil dipstick.
So not screw the dipstick into engine as
checking.
If oil level is nearly low level, fill out
recommended oil to upper level.

Oil Change

Caution

Drain oil as engine warmed up so that makes
sure oil can be drained smoothly and completely.

Place an oil pan under the ATV, and remove oil
drain bolt.
After drained, make sure washer can be re-used.
Install oil drain bolt.

Torque value：3.5~4.5kgf-m

Engine Oil Strainer Clean

3. LUBRICATION SYSTEM

Drain bolt

Drain engine oil out.
Remove oil strainer and spring.
Clean oil strainer.
Check if O-ring can be re-used.
Install oil strainer and spring.
Install oil strainer cap.

Torque value：1.3~1.7kgf-m

Add oil to crankcase (oil viscosity SAE 10W-30)
Recommended using King serial oil.

Engine oil capacity: 1200c.c. when replacing

Install dipstick, start the engine for running
several minutes.
Turn off engine, and check oil level again.
Check if engine oil leaks.

Oil strainer cap

O-ring

Oil strainer

3-3

To this chapter contents

3. LUBRICATION SYSTEM

Oil Pump

Oil Pump Removal

Remove generator and starting gear. (Refer to
chapter 10) 。

Remove cir clip and take out oil pump driving
chain and sprocket.

Make sure that pump shaft can be rotated freely.
Remove 2 screws on the oil pump, and then
remove oil pump.

Oil Pump Disassembly

Remove the screws on oil pump cover and
remove the cover.
Remove oil pump shaft roller and shaft.

Clip

2 screws

1 screw

3-4

Roller

To this chapter contents

Oil Pump Inspection

Check the clearance between oil pump body and
outer rotor.

Limit: 0.25 mm

Check clearance between inner and outer rotors.
Limit: 0.20 mm

Check clearance between rotor side face and
pump body

Limit: 0.12 mm

Oil Pump Re-assembly

Install inner and outer rotors into the pump body.
Align the indent on driving shaft with that of inner
rotor.
Install the oil pump shaft and roller.
Install the oil pump cover and fixing pins properly.

3. LUBRICATION SYSTEM

Pins

3-5

To this chapter contents

3. LUBRICATION SYSTEM

Tighten the oil pump screw.

Oil Pump Installation

Install the oil pump, and then tighten screws.

Torque value：0.1~0.3kgf-m

Make sure that oil pump shaft can be rotated
freely.

Install oil pump drive chain and sprocket, and
then install cir clip onto oil pump shaft.

Install starting gear and generator.
(Refer to chapter 10)

1 screw

Roller

2 screws

Clip

3-6

To this chapter contents

Gear Oil

Gear Oil Change

Remove oil join bolt.
Remove drain bolt and drain gear oil out.
Install the drain bolt after drained.

Torque value: 1.1~1.5kgf-m

Make sure that the drain bolt washer can be
re-used.
Add oil to specified quantity from the join hole.

Gear Oil Quantity: 650c.c. when replacing

Make sure that the join bolt washer can be
re-used, and install the bolt.

Torque value: 3.5~4.5kgf-m

Start engine and run engine for 2-3 minutes.
Turn off engine and make sure that oil level is in
correct level.
Make sure that no oil leaking.

3. LUBRICATION SYSTEM

Gear oil join bolt

Gear oil drain bolt

3-7

To this chapter contents

3. LUBRICATION SYSTEM

Notes:

3-8

Home page

Contents

Mechanism Diagram ............................ 4-1

Precautions in Operation..................... 4-2

Trouble Diagnosis................................ 4-3

Carburetor Remove / Install ................ 4-4

Air Cut-Off Valve .................................. 4-5

Mechanism Diagram

Fuel tank cap

Fuel tank

4. FUEL SYSTEM

Throttle Valve.......................................4-6

Float Chamber......................................4-7

Adjustment of Idle Speed....................4-9

Fuel Tank..............................................4-10

Air Cleaner............................................4-11

Fuel unit

4

Inlet pipe

Auto fuel cock

Carburetor

Fuel strainer

4-1

To this chapter contents

4. FUEL SYSTEM

Precautions in Operation

General Information

Warning

Gasoline is a low ignition point and explosive materials, so always work in a well-ventilated place and
strictly prohibit flame when working with gasoline.

Cautions

y Do not bend off throttle cable. Damaged throttle cable will make unstable drive-ability.
y When disassembling fuel system parts, pay attention to O-ring position, replace with new one as

re-assembly

y There is a drain screw in the float chamber for draining residual gasoline.
y Do not disassemble air cut valve arbitrarily.

Specification

ITEM UA25A

Carburetor diameter Ø22mm
I.D. number PTG 050
Fuel level 14.8mm
Main injector # 110
Idle injector # 35
Idle speed 1700 ± 100rpm
Throttle handle clearance 1~3 mm
Pilot screw 2 turns

Tool
Special service tools

Vacuum/air pressure pump
Fuel level gauge

4-2

To this chapter contents

Trouble Diagnosis

Poor engine start

y No fuel in fuel tank
y Clogged fuel tube
y Too much fuel in cylinder
y No spark from spark plug(malfunction of ignition

system )

y Clogged air cleaner
y Malfunction of carburetor chock
y Malfunction of throttle operation

Stall after started

y Malfunction of carburetor chock
y Incorrect ignition timing
y Malfunction of carburetor
y Dirty engine oil
y Air existing in intake system
y Incorrect idle speed

4. FUEL SYSTEM

Mixture too lean

y Clogged fuel injector
y Vacuum piston stick and closed
y Malfunction of float valve
y Fuel level too low in float chamber
y Clogged fuel tank cap vent
y Clogged fuel filter
y Obstructed fuel pipe
y Clogged air vent hose
y Air existing in intake system

Mixture too rich

y Clogged air injector
y Malfunction of float valve
y Fuel level too high in float chamber
y Malfunction of carburetor chock
y Dirty air cleaner

Rough idle

y Malfunction of ignition system
y Incorrect idle speed
y Malfunction of carburetor
y Dirty fuel

Intermittently misfire as acceleration

y Malfunction of ignition system

Late ignition timing

y Malfunction of ignition system
y Malfunction of carburetor

Power insufficiency and fuel consuming

y Fuel system clogged
y Malfunction of ignition system

4-3

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4. FUEL SYSTEM

Carburetor Remove / Install

Removal

Drain out fuel in the float chamber.

Loosen the choke cable fixed iron sheet screw
from plate.
Remove the choke cable.

Disconnect the fuel hose.
Release the clamp strip of air cleaner.

Remove the carburetor upper parts from the
carburetor.
Release the 2 nuts of carburetor insulator, and
then remove the carburetor.

Drain bolt

Vacuum pipe

1 screw

Choke cable

Fuel pipe

Clamp

Installation

Install in reverse order of removal procedures.

4-4

2 nuts

To this chapter contents

Air Cut-Off Valve

Disassembly

Remove 2 screws.

Remove air cut-off valve cover, spring and valve.

Inspection

Check the valve is in normal.
If the valve is in normal, it will restrict air-flow.
If air-flow is no restricting, replace carburetor
assembly.
Check the vacuum pipe o-ring is in normal.

2 screws

O-ring

4. FUEL SYSTEM

Air cut-off valve

Spring

Cover

Assembly

Install in reverse order of removal procedures.

4-5

To this chapter contents

4. FUEL SYSTEM

Throttle Valve

Disassembly

Remove carburetor upper parts, and then remove
throttle valve and throttle cable.

Disconnect the throttle cable from the throttle
valve and remove the valve spring.
Remove the fuel needle clamp and fuel needle.

Assembly

Place the fuel needle onto the throttle valve and
clip it with needle clamp.
Install the sealed cap, carburetor upper part, and
throttle valve spring.
Connect the throttle valve cable to the throttle
valve.
Install the throttle valve into the carburetor body.

Throttle valve

Throttle
cable

Spring

Needle clamp

Fuel needle clip
Fuel needle

Caution

Align the groove inside the throttle valve with the
throttle stopper screw of the carburetor body.

Tighten the carburetor upper part.
Adjust the free play of throttle valve cable.

4-6

To this chapter contents

Float Chamber

Disassembly

Remove 3 mounting screws and remove float
chamber cover.

Remove the fuel level plate, float pin, float and
float valve.

Inspection

Check float valve and valve seat for damage,
blocking.
Check float valve for wearing, and check valve
seat face for wear, dirt.

Float

Fuel level plate

4. FUEL SYSTEM

3 Screws

Float valve

Pin

Pin

Caution

In case of worn out or dirt, the float valve and
valve seat will not tightly close causing fuel level
to increase and as a result, fuel flooding. A worn
out or dirty float valve must be replaced with a
new a new one.

Float

Check for wear or damage

Float valve

4-7

To this chapter contents

4. FUEL SYSTEM

Remove main jet, needle jet holder, needle jet,
slow jet and air adjustment screw.

Caution

Take care not to damage jets and adjust screw.

y Before removing adjustment screw, turn it all

the way down and note the number of turns.

y Does not turn adjust screw forcefully to avoid

damaging valve seat face.

Clean jets with cleaning fluid. Then use
compressed air to blow the dirt off.
Blow carburetor body passages with compressed
air.

Assembly

Install main jet, needle jet holder, needle jet, slow
jet and air adjustment screw.

Caution

Needle jet holder

Needle jet

Main jet

Slow jet

Set the air adjustment screw in according to
number of turns noted before it was removed.

Install the float valve, float, and float pin.

Checking fuel level

Caution

y Check again to ensure float valve, float for

proper installation.

y To ensure correct measurement, position the

float meter in such a way so that float chamber
face is vertical to the main jet.

Fuel level: 14.8mm

Installation of carburetor

Install carburetor in the reverse order of removal.
Following adjustments must be made after
installation.

˙Throttle cable adjustment.
˙Idle adjustment

Air adjustment screw

Float gauge

Lock nut

4-8

Throttle adjustment screw

To this chapter contents

Adjustment of Idle Speed

Caution

y Air screw was set at factory, so no adjustment

is needed. Note the number of turns it takes to
screw it all the way in for ease of installation.

y The parking brake must be used to stop the

ATV to perform the adjustments.

Use a tachometer when adjusting engine RPM.
Screw in air adjustment screw gently, then back up
to standard turns.

Standard turns: 2 turns

Warm up engine; adjust the throttle stopper screw
of throttle valve to standard RPM.

Idle speed rpm: 1700 ± 100 rpm

Connect the hose of exhaust analyzer to exhaust
front end. Press test key on the analyzer.
Adjust the pilot screw and read CO reading on the
analyzer

CO standard value: 1.0~1.5 %

Accelerate in gradual increments; make sure rpm
and CO value are in standard value after engine
running in stable. If rpm and CO value fluctuated,
repeat the procedures described above for
adjusting to standard value.

Parking brake

Air adjustment screw

4. FUEL SYSTEM

Throttle valve stopper screw

4-9

To this chapter contents

4. FUEL SYSTEM

Fuel Tank

Fuel unit removal

Open the seat.
Remove the front cover and fuel tank.
Remove the side covers and lower side covers.
Remove the front fender.
(Covers remove please
Disconnect fuel unit coupler.
Remove fuel unit (4 bolts).

Caution

˙Do not bend the float arm of fuel unit
˙Do not fill out too much fuel to fuel tank.

Fuel unit inspection (Refer to electrical equipment

chapter 17).

Fuel unit installation

Install the gauge in the reverse order of removal.

refer chapter 13)

4 bolts

Coupler

Caution

Do not forget to install the gasket of fuel unit or
damage it.

Fuel tank removal

Open the seat.
Remove the front cover and fuel tank.
Remove the side covers and lower side covers.
Remove the front fender.
(Covers remove please
Disconnect fuel unit coupler.
Remove fuel unit (4 bolts).
Remove the fuel tube.
Remove the

Remove fuel tank front and rear side 4 bolts, and
then remove fuel tank.

vacuum tube.

refer chapter 13)

Vacuum tube

FRONT

Fuel tube

Installation

Install the tank in the reverse order of removal.

4-10

REAR

4 bolts

To this chapter contents

Air Cleaner

Removal

Loosen the clamp strip of air cleaner and
carburetor, and then remove the vapor hose.

Loosen the clamp strip of air cleaner, and then
remove the air cleaner vapor hose.
Remove the air cleaner (4 bolts).

Installation

Install the tank in the reverse order of removal.

Cleaning air cleaner element

Remove the air cleaner cover (4 catch hooks).

Remove element mounting screw.
Loosen the clamp strip of air cleaner element, and
then remove the air cleaner element.
Clean the element with non-flammable or
high-flash point solvent and then squeeze it for
dry.

Clamp

Clamp

4. FUEL SYSTEM

Clamp

4 bolts

4 hooks

1 screw

Caution

Never use gasoline or acid organized solvent to
clean the element.

Soap the element into cleaning engine oil and then
squeeze it out. Install the element onto the
element seat and then install the air cleaner cover.

4-11

To this chapter contents

4. FUEL SYSTEM

Notes:

4-12

Home page

Contents

Precautions in Operation..................... 5-1

Engine Installation................................ 5-6

5. ENGINE REMOVAL

Removal of Engine ............................... 5-2

Precautions in Operation

General Information

y The engine has to be supported with special service tools that can be lifted or adjustable.
y Engine shall be removal in the conditions of necessary repair or adjustment to the only.
y The following parts can be serviced as engine mounted on frame:

Carburetor.
Drive pulley, drive belt, clutch, and movable drive face assembly.
Start motor.
AC. Generator, oil pump and start one way clutch.
Transmission.

Specification

5

Item Capacity

Replacement 1200 c.c.

Engine oil capacity

Disassembly 1400 c.c.

Replacement 650 c.c.

Gear oil capacity

Disassembly 750 c.c.

Engine & radiator 780 c.c.

Coolant capacity

Reservoir 420 c.c. AS indicator shown

Total 1200 c.c.

Torque Value

Engine hanger bolt 7.5~9.5kgf-m
Exhaust muffler mounting bolt 2.8~3.2kgf-m

Exhaust muffler connection nut 1.0~1.4kgf-m

5-1

To this chapter contents

5. ENGINE REMOVAL

Removal of Engine

Remove the seat.

Remove battery negative post (-).
Remove battery positive (+) post.

Remove front fender and the footrest (refer chapter 13).

Remove starter motor wire.

Remove the spark plug cap.

Disconnect A.C. Generator wire couplers.

Positive

Spark plug cap

A.C.G wire couplers

Negative

Starter motor wire

5-2

To this chapter contents

Remove muffler protect (2 bolts).

Loosen muffler front side bolt.

Remove 2 bolts, and then remove the exhaust muff ler.

Remove 2 nuts, and then remove exhaust pipe.

5. ENGINE REMOVAL

2 bolts

2 bolts

2 bolts

2 nuts

5-3

To this chapter contents

5. ENGINE REMOVAL

Loosen 1 screw and disconnect the choke cable.

Remove fuel pipe and vacuum pipe.
Release the clamp strip of air cleaner duct.

Disconnect the carburetor upper parts and cable.

Release the 2 nuts of carburetor insulator, and
then remove the carburetor.

Release the clamp strips of left crankcase cover
ducts, and then remove the ducts.

Vacuum pipe

2 nuts

Clamps

1 screw

Choke cable

Fuel pipe

Clamp

5-4

To this chapter contents

Remove coolant drain bolt, and drain out coolant.
Remove coolant inlet hoses from water pump.

Remove the thermo-sensor wire, by-pass pipe and
coolant outlet hose.

Remove gear change lever (1 bolt).

Remove change switch couplers.

Water hoses clamp

Drain bolt

By-pass pipe

Thermo-sensor wire

5. ENGINE REMOVAL

Outlet hose

1 bolt

Change switch couplers

5-5

To this chapter contents

5. ENGINE REMOVAL

Loosen speedometer cable mounting nut, and
then remove the cable.
Remove 3 bolts and remove drive chain protector.
Turn the socket bolt clockwise, and then remove
speedometer gear box.

Caution

The socket bolt is provided with left turn
thread.

Remove 2 bolts, and then remove the drive
sprocket fixing plate, drive chain and drive
sprocket.

Remove the rear side engine hanger mounting
nuts and bolts.

Remove the front side engine hanger mounting
nut and bolt
Remove left side engine hanger, and then remove
engine by left side.

Speedometer cable

Socket bolt

2 bolts

3 bolts

Engine Installation

Check if the bush of engine hanger parts for
damage.
Install engine in the reverse procedures of
removal.

Caution

y Pay attention of foot & hand safety as engine

installation to avoid hurting.

y Do not bend or twist wires.
y Cables wires have to be routed in accordance

with normal layout.

Engine hanger Bolt:
Torque value: 7.5~9.5kgf-m

5-6

2 nuts

1 nut

Home page

Contents

Mechanism Diagram··························· 6-1
Precautions in Operation··················· 6-2
Troubleshooting·································· 6-3
Cylinder Head Removal······················ 6-4
Cylinder Head Inspection··················· 6-7

Mechanism Diagram

1.0~1.4kgf-m

6. CYLINDER HEAD/VALVE

Valve Stem Replacement··················· 6-10
Valve Seat Inspection and Service··· 6-11
Cylinder Head Reassembly··············· 6-13
Cylinder Head Installation················· 6-14
Valve Clearance Adjustment············· 6-16

6

1.0~1.4kgf-m

1.0~1.4kgf-m

1.0~1.4kgf-m

0.7~1.1kgf-m

1.0~1.4kgf-m

3.6~4.0kgf-m

2.4~3.0kgf-m

1.0~1.2kgf-m

1.0~1.2kgf-m

6-1

To this chapter contents

6. CYLINDER HEAD/VALVE

Precautions in Operation

General Information

y This chapter is contained maintenance and service for cylinder head, valve, and camshaft as well as

rocker arm.
y Cylinder head service can be carried out when engine is in frame.

Specification

Item Standard Limit

Compression pressure 12±2 kg/cm2 ---

Camshaft Height of cam lobe

ID of valve rocker arm 11.982~12.000 12.080

Rocker arm

OD of valve rocker arm shaft 11.966~11.984 11.936

OD of valve stem

Intake 34.880 34.860
Exhaust 34.740 34.725

Intake 4.975~4.990 4.900
Exhaust

4.950~4.975

4.900

ID of valve guide 5.000~5.012 5.030
Clearance between

valve stem and guide

Valve

Free length of valve
spring

Valve seat width 1.600 ---

Valve clearance

Tilt angle of cylinder head --- 0.050

Intake 0.010~0.037 0.080
Exhaust 0.025~0.062 0.100
Inner 38.700 35.200
outer 40.400 36.900

Intake 0.10±0.02mm --­Exhaust 0.15±0.02mm ---

Torque Value

Cylinder head cover bolt 1.0~1.4kgf-m
Exhaust pipe stud bolt 2.4~3.0kgf-m
Cylinder head bolt 1.0~1.4kgf-m
Cylinder head Nut 3.6~4.0kgf-m
Sealing bolt of cam chain auto-tensioner 0.8~1.2kgf-m
Bolt of cam chain auto-tensioner 1.2~1.6kgf-m
Cylinder side cover bolt 1.0~1.4kgf-m
Cam sprocket bolt 1.0~1.4kgf-m
Tappet adjustment screw nut 0.7~1.1kgf-m
Spark plug 1.0~1.2kgf-m

Tools
Special service tools

Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve spring compressor

6-2

To this chapter contents

6. CYLINDER HEAD/VALVE

Troubleshooting

Engine performance will be affected by troubles on engine top parts. The trouble usually can be
determined or by performing cylinder compression test and judging the abnormal noise generated.

Low compression pressure

1. Valve

y Improper valve adjustment

y Burnt or bent valve

y Improper valve timing

y Valve spring damage

y Valve carbon deposit.

2. Cylinder head

y Cylinder head gasket leaking or damage

y Tilt or crack cylinder

3. Piston

y Piston ring worn out.

High compression pressure

y Too much carbon deposit on combustion chamber or piston head

Noise

y Improper valve clearance adjustment
y Burnt valve or damaged valve spring
y Camshaft wear out or damage
y Chain wear out or looseness
y Auto-tensioner wear out or damage
y Camshaft sprocket
y Rocker arm or rocker arm shaft wear out

6-3

To this chapter contents

6. CYLINDER HEAD/VALVE

Cylinder Head Removal

Remove engine. (Refer to chapter 5)
Remove the inlet pipe (2 nuts).

Remove 1 bolt of thermostat and then remove the
thermostat.
Remove hole bolt and spring for the cam chain
tensioner.
Loosen 2 bolts, and then remove tensioner.
Remove thermostat (2 bolts).

Remove Air Injection system (AI) pipe mounting
bolts.
Remove spark plug.

Remove the side cover mounting blots of cylinder
head, and then take out the side cover.

2 nuts

Tensioner bolts

4 bolts

3 bolts

Thermostat bolts

Spark plug

6-4

To this chapter contents

Remove left crankcase cover, and turn the
Turn the drive face, and align the timing mark on
the sprocket with that of cylinder head, piston is at
TDC position.
Remove cam sprocket bolts and then remove the
sprocket by prying chain out.

Remove cam shaft setting plate (1 bolt).

Remove rocker arm shafts and rocker arms.

Special Service Tool:
Rocker arm and cam shaft puller

Remove cam shafts.

Special Service Tool:
Rocker arm and cam shaft puller

6. CYLINDER HEAD/VALVE

Timing mark

2 bolts

Cam shaft setting plate

Rocker arm shafts

Rocker arm shaft and

cam shaft puller

Cam shafts

Rocker arm

shaft and cam
shaft puller

6-5

To this chapter contents

6. CYLINDER HEAD/VALVE

Remove the 2 cylinder head mounting bolts from
cylinder head right side, and then remove 4 nuts
and washers from cylinder head upper side.
Remove the cylinder head.

Remove cylinder head gasket and 2 dowel pins.
Remove chain guide.
Clean up residues from the matching surfaces of
cylinder and cylinder head.

Caution

y Do not damage the matching surfaces of

cylinder and cylinder head.

y Avoid residues of gasket or foreign materials

falling into crankcase as cleaning.

Use a valve cotter remove & assembly tool to
press the valve spring, and then remove valves.

4 Nuts

2 bolts

Gasket

Chain guide

Dowel pins

Caution

y In order to avoid loosing spring elasticity, do not

press the spring too much. Thus, press length

is based on the valve cotter in which can be

removed.

Special Service Tool:
Valve cotter remove & assembly tool

Valve cotter remove

and assembly tool

Inlet valve

Exhaust valve

Inner spring

Outer spring

Spring retainer

Cotter

6-6

To this chapter contents

Remove valve stem seals.

Clean carbon deposits in combustion chamber.
Clean residues and foreign materials on cylinder
head matching surface.

Caution

Do not damage the matching surface of cylinder
head.

Cylinder Head Inspection

Check if spark plug and valve holes are cracked.
Measure cylinder head warp with a straightedge
and thickness gauge.

Service limit: 0.05 mm

Camshaft

Inspect cam lobe height for damaged.

Service Limit:

IN: Replacement when less than 34.860mm
EX: Replacement when less than 34.725mm

Inspect the camshaft bearing for looseness or
wear out. If any damage, replace whole set of
camshaft and bearing.

6. CYLINDER HEAD/VALVE

Valve stem seals

6-7

To this chapter contents

6. CYLINDER HEAD/VALVE

Rocker Arm

Measure the cam rocker arm I.D., and wear or
damage, oil hole clogged?

Service Limit: Replace when it is less than

12.080 mm.

Rocker Arm Shaft

Measure the active O.D. of the cam rocker arm
shaft and cam rocker arm.

Service Limit: Replace when it is less than

11.936 mm.

Calculate the clearance between the rocker arm
shaft and the rocker arm.

Service Limit: Replace when it is less than 0.10
mm.

Valve spring free length

Measure the free length of intake and exhaust
valve springs.

Service limit:
Inner spring 35.20 mm
Outer spring 36.90 mm

Valve stem

Check if valve stems are bend, crack or burn.
Check the operation condition of valve stem in
valve guide, and measure & record the valve stem
outer diameter.

Service Limit: IN: 4.90 mm

EX: 4.90 mm

6-8

To this chapter contents

Valve guide

Caution

Before measuring the valve guide, clean carbon
deposits with reamer.

Tool: 5.0 mm valve guide reamer

Measure and record each valve guide inner
diameters.

Service limit: 5.03 mm

The difference that the inner diameter of valve
guide deducts the outer diameter of valve stem is
the clearance between the valve stem and valve
guide.

Service Limit: IN→0.08 mm

EX→0.10 mm

6. CYLINDER HEAD/VALVE

5.0 mm valve guide reamer

Caution

If clearance between valve stem and valve guide
exceeded service limit, check whether the new
clearance that only replaces new valve guide is
within service limit or not. If so, replace valve
guide.

Correct it with reamer after replacement.
If clearance still exceeds service limit after
replaced valve guide, replace valve stem too.

Caution

It has to correct valve seat when replacing valve
guide.

6-9

To this chapter contents

6. CYLINDER HEAD/VALVE

Valve Stem Replacement

Heat up cylinder head to 100~150 ℃ with heated
plate or toaster.

Caution

y Do not let torch heat cylinder head directly.

Otherwise, the cylinder head may be deformed

as heating it.

y Wear on a pair of glove to protect your hands

when operating.

Hold the cylinder head, and then press out old
valve guide from combustion chamber side.

Tool: Valve guide driver: 5.0 mm

Caution

y Check if new valve guide is deformation after

pressed it in.

y When pressing in the new valve guide, cylinder

head still have to be kept in 100~150

℃.

Valve guide driver

5.0mm

Valve guide driver

5.0 mm

Adjust the valve guide driver and let valve guide
height is in 13 mm.
Press in new valve guide from rocker arm side.

Tool: Valve guide driver: 5.0 mm

Wait for the cylinder head cooling down to room
temperature, and then correct the new valve guide
with reamer.

Caution

y Using cutting oil when correcting valve guide

with a reamer.

y Turn the reamer in same direction when it be

inserted or rotated.
Correct valve seat, and clean up all metal residues

from cylinder head.

Tool: Valve guide reamer: 5.0 mm

Valve guide reamer 5.0 mm

6-10

To this chapter contents

Valve Seat Inspection and Service

Clean up all carbon deposits onto intake and
exhaust valves.
Apply with emery slightly onto valve contact face.
Grind valve seat with a rubber hose or other
manual grinding tool.

Caution

y Do not let emery enter into between valve stem

and valve guide.

y Clean up the emery after corrected, and apply

with engine oil onto contact faces of valve and
valve seat.

Remove the valve and check its contact face.

Caution

Replace the valve with new one if valve seal is
roughness, wear out, or incomplete contacted
with valve seat.

Valve seat inspection

If the valve seat is too width, narrow or rough,
corrects it.

Valve seat width

Service limit: 1.6mm

Check the contact condition of valve seat.

Valve seat grinding

The worn valve seat has to be ground with valve
seat chamfer cutter.
Refer to operation manual of the valve seat
chamfer cutter.
Use 45° valve seat chamfer cutter to cut any rough
or uneven surface from valve seat.

Caution

After valve guide had been replaced, it has to be
ground with 45° valve seal chamfer cutter to
correct its seat face.

Use 32° cutter to cut a quarter upper parts out.

6. CYLINDER HEAD/VALVE

Valve seat width

Roughness

45°

Old valve seat width

32°

6-11

To this chapter contents

6. CYLINDER HEAD/VALVE

Use 60° cutter to cut a quarter lower parts out.
Remove the cutter and check new valve seat.

Use 45° cutter to grind the valve seat to specified
width.

Caution

Make sure that all roughness and uneven faces
had been ground.

Grind valve seat again if necessary.

Coat the valve seat surface with red paint.
Install the valve through valve guide until the valve
contacting with valve seat, slightly press down the
valve but do not rotate it so that a seal track will be
created on contact surface.

Contact surface too high

Old valve seat width

60°

1.0mm

Old valve seat width

45°

Caution

The contact surfaces of valve and valve seat are
very important to the valve sealing capacity.

If the contact surface too high, grind the valve seat
with 32° cutter.
Then, grind the valve seat to specified width.

If the contact surface too low, grind the valve seat
with 60° cutter.
Then, grind the valve seat to specified width.

6-12

Contact surface too low

32°

Old valve seat width

60°

V

To this chapter contents

After the valve seat ground, coat valve seat
surface with emery and then slightly press the
ground surface.
Clean up all emery coated onto cylinder and valve
after ground.

Cylinder Head Reassembly

Lubricate valve stem with engine oil, and then
insert the valve into valve guide.
Install new valve stem oil seal.
Install valve springs and retainers.

Caution

The closed coils of valve spring should face down
to combustion chamber.

Use a valve cotter remove & assembly tool to
press the valve spring, and then remove valves.

6. CYLINDER HEAD/VALVE

Valve spring retainer

alve cotter

Valve spring

Valve stem seal

Inlet valve

Exhaust valve

Caution

In order to avoid damaging the valve stem and
the cylinder head, in the combustion chamber
place a rag between the valve spring
remover/installer as compressing the valve spring
directly.

Special Service Tool:
Valve cotter remove & assembly tool

Tap the valve stems gently with a plastic hammer
to make sure valve retainer and valve cotter is
settled.

Caution

Place and hold cylinder head on to working table
so that can prevent from valve damaged.

Valve cotter remove

and assembly tool

6-13

To this chapter contents

6. CYLINDER HEAD/VALVE

Cylinder Head Installation

Clean up all residues and foreign materials onto
the matching surfaces of both cylinder and
cylinder head.
Install chain guide, dowel pins and a new cylinder
head gasket onto the cylinder.

Caution

Do not damage the matching surfaces of cylinder
and cylinder head.
Avoid residues of gasket or foreign materials
falling into crankcase as cleaning.

Install 4 washers and tighten 4 nuts on the cylinder
head upper side, and then tighten 2 cylinder head
mounting bolts of cylinder head right side.

Torque value:
Nut 3.6~4.0kgf-m
Bolt 1.0~1.4kgf-m

Install camshaft into cylinder head, and install
rocker arm, rocker arm shaft.

Install rocker arm pin mounting plate.

Gasket

Chain guide

Dowel pins

4 Nuts

2 bolts

Cam shaft setting plate

6-14

To this chapter contents

Install cam chain on to sprocket and align the
timing mark on the sprocket with that of cylinder
head.
Align sprocket bolt hole with camshaft bolt hole.
Tighten the sprocket mounting bolts.

Caution

Make sure timing marks are matched.

Install cylinder head side cover (3 bolts).
Install thermostat (2 bolts).

Loosen auto tensioner adjustment bolt and
remove bolt and spring.
Install tensioner and install spring and adjustment
bolt.

Install cylinder cover (4 bolts).

6. CYLINDER HEAD/VALVE

2 bolts

3 bolts

Tensioner adjustment bolt

Thermostat bolts

Timing mark

4 bolts

6-15

To this chapter contents

6. CYLINDER HEAD/VALVE

Install Air Injection system (AI) pipe. (4 bolts)
Install inlet pipe onto cylinder
Install and tighten spark plug

Torque value: 1.0~2.0kgf-m

Caution

This model is equipped with more precision
4-valve mechanism so its tighten torque can not
be exceeded standard value in order to avoid
causing cylinder head deformation, engine noise
and leaking so that motorcycle’s performance be
effected.

Install the engine onto frame (refer chapter 5).

Valve Clearance Adjustment

Loosen Air Injection system (AI) pipe upper side
bolt (2 bolts).
Remove cylinder head cover.

Remove the cylinder head side cover.
Remove left crankcase cover, and turn the drive
face, and align the timing mark on the cam
sprocket with that of cylinder head, piston is at
TDC position.
Loosen valve clearance adjustment nuts and bolts
located on valve rocker arm.
Measure and adjust valve clearance with feeler
gauge.
After valve clearance had been adjusted to
standard value, hold adjustment bolt and then
tighten the Adjustment nut.

Standard Value: IN 0.10 ± 0.02 mm

EX 0.15 ± 0.02 mm

Install the cylinder head side cover.
Start the engine and make sure that engine oil
flows onto the cylinder head.
Stop the engine after confirmed, and then install
the cylinder head cover and AI pipe.

4 bolts

Spark plug

Timing mark

Caution

y If lubricant does not flow to cylinder head,

engine components will be worn out seriously.

Thus, it must be confirmed.

y When checking lubricant flowing condition, run

the engine in idle speed. Do not accelerate

engine speed.

6-16

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Contents

7. CYLINDER/PISTON

Mechanism Diagram···························· 7-1
Precautions in Operation ···················· 7-2
Trouble Diagnosis································ 7-2
Cylinder and Piston Removal ············· 7-3

Mechanism Diagram

Piston Ring Installation ···················7-6
Piston Installation ···························· 7-7
Cylinder Installation························· 7-7

1.0~1.4kgf-m

7

0.8~1.2kgf-m

7-1

To this chapter contents

7. CYLINDER/PISTON

Precautions in Operation

General Information

y Both cylinder and piston service cannot be carried out when engine mounted on frame.

UA25A

Specification Unit：mm

Item Standard Limit

Cylinder

Piston/
Piston ring

OD of piston pin 16.994~17.000 16.960
Clearance between piston and piston pin 0.002~0.014 0.020
ID of connecting rod small-end 17.016~17.034 17.064

ID 70.995~71.015 71.100
Bend - 0.050

Clearance between piston
rings

Ring-end gap

OD of piston (2nd) 70.430~70.480 70.380
Clearance between piston and cylinder 0.010~0.040 0.100
ID of piston pin boss 17.002~17.008 17.020

Top ring 0.015~0.050 0.090

nd

ring 0.015~0.050 0.090

2
Top ring 0.150~0.300 0.500
2nd ring 0.300~0.450 0.650
Oil ring side rail 0.200~0.700 -

Trouble Diagnosis

Low or Unstable Compression Pressure

y Cylinder or piston ring worn out

Knock or Noise

y Cylinder or piston ring worn out
y Carbon deposits on cylinder head top-side
y Piston pin hole and piston pin wear out

7-2

Smoking in Exhaust Pipe

y Piston or piston ring worn out
y Piston ring installation improperly
y Cylinder or piston damage

Engine Overheat

y Carbon deposits on cylinder head top side
y Cooling pipe clogged or not enough in coolant

flow

To this chapter contents

7. CYLINDER/PISTON

Cylinder and Piston Removal

Remove cylinder head (refer to chapter 6).
Remove coolant hose from cylinder.
Remove cylinder.

Cover the holes of crankcase and cam chain with
a piece of cloth.
Remove piston pin clip, and then remove piston
pin and piston.

Remove cylinder gasket and dowel pin.
Clean up all residues or foreign materials from
the two matching surfaces of cylinder and
crankcase.

Coolant hose

Dowel pins

Caution

y Soap the residues into solvent so that the

residues can be removed more easily.

Inspection

Check if the inner diameter of cylinder is wear out
or damaged.
In the 3 positions, top, center and bottom, of
cylinder, measure the X and Y values respective
in the cylinder.

Service limit: 71.100 mm

Top
Center

Bottom

7-3

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7. CYLINDER/PISTON

Check cylinder if warp.

Service limit: 0.05 mm

Measure clearance between piston rings and
grooves.

Service Limit: Top ring: 0.09 mm

nd

2

ring: 0.09 mm

Remove piston rings

Check if the piston rings are damaged or its
grooves are worn.

Caution

Pay attention to remove piston rings because
they are fragile.

Place piston rings respective into cylinder below
20 mm of cylinder top. In order to keep the piston
rings in horizontal level in cylinder, push the rings
with piston.

Service Limit: Top ring: 0.50 mm

nd

ring: 0.65 mm

2

7-4

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7. CYLINDER/PISTON

Measure the outer diameter of piston pin.

Service Limit: 16.96 mm

Measure the inner diameter of connecting rod
small end.

Service Limit: 17.064 mm

Measure the inner diameter of piston pin hole.
Service Limit: 17.02 mm
Calculate clearance between piston pin and its
hole.

Service Limit: 0.02 mm

Measure piston outer diameter.

Caution

The measurement position is 10 mm distance
from piston bottom side, and 90° to piston pin.

Service limit：70.380 mm

Compare measured value with service limit to
calculate the clearance between piston and
cylinder.

7-5

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7. CYLINDER/PISTON

Piston Ring Installation

Clean up piston top, ring groove, and piston surface.
Install the piston ring onto piston carefully.
Place the openings of piston ring as diagram shown.

Caution

y Do not damage piston and piston rings as installation.
y All marks on the piston rings must be forwarded to up side.
y Make sure that all piston rings can be rotated freely after installed.

Top ring

nd

2

ring

Oil ring

Top groove

nd

2

groove

Oil groove

7-6

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7. CYLINDER/PISTON

Clean up all residues and foreign materials on
the matching surface of crankcase. Pay
attention to not let these residues and foreign
materials fall into crankcase.

Caution

Soap the residues into solvent so that the
residues can be removed more easily.

Piston Installation

Install piston and piston pin, and place the IN
marks on the piston top side forward to inlet
valve.

Install new piston pin clip.

Caution

y Do not let the opening of piston pin clip align

with the piston cutout.

y Place a piece of cloth between piston and

crankcase in order to prevent snap ring from
falling into crankcase as operation.

IN mark

Clip end gap

Cylinder Installation

Install dowel pins and new gasket.

Cutout

Dowel pins

7-7

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7. CYLINDER/PISTON

Coat some engine oil to inside of cylinder, piston
and piston rings.
Care to be taken when installing piston into
cylinder. Press piston rings in one by one as
installation.

Caution

Do not push piston into cylinder forcefully
because piston and piston rings will be
damaged.。

Install coolant hose onto cylinder.
Install cylinder head (refer to Chapter 6).

Coolant hose

7-8

Home page

Contents

Mechanism Diagram ··························· 8-1
Maintenance Description···················· 8-2
Trouble Diagnosis······························· 8-2
Left Crankcase Cover ························· 8-3

Mechanism Diagram

8. V-BELT DRIVING SYSTEM

Drive Belt··············································8-5
Drive Face·············································8-7
Clutch Outer/Driven Pulley··················8-10

8

5.0~6.0kgf-m

8.5~10.5kgf-m

5.0~6.0kgf-m

8-1

To this chapter contents

8. V-BELT DRIVING SYSTEM

Maintenance Description

Precautions in Operation
General Information

y Drive face, clutch outer, and driven pulley can be serviced on the motorcycle.
y Drive belt and drive pulley must be free of grease.

Specification

Item Standard value Limit
Driving belt width 24.000 mm 22.500 mm
OD of movable drive face boss 29.946~29.980 mm 29.926 mm
ID of movable drive face 30.000~30.040 mm 30.060 mm
OD of weight roller 19.500~20.000 mm 19.000 mm
ID of clutch outer 144.850~145.150 mm 145.450 mm
Thickness of clutch weight 6.000 mm 3.000 mm
Free length of driven pulley spring 102.400 mm 97.400 mm
OD of driven pulley boss 40.950~40.990 mm 40.930 mm
ID of driven face 41.000~41.050 mm 41.070 mm
Weight of weight roller 17.700~18.300 g 17.200 g

Torque value

y Drive face nut: 8.5~10.5kgf-m
y Clutch outer nut: 5.0~6.0kgf-m
y Drive plate nut: 5.0~6.0kgf-m

Special Service Tools

Clutch spring compressor: SYM-2301000
Inner bearing puller:
Clutch nut wrench 39 x 41 mm:
Universal holder:
Bearing driver:

SYM-6204002

SYM-9020200

SYM-2210100

SYM-9100100

Trouble Diagnosis

Engine can be started but motorcycle can
not be moved

1. Worn drive Belt

2. Worn drive face

3. Worn or damaged clutch weight

4. Broken driven pulley

Shudder or misfire when driving

1. Broken clutch weight

2. Worn clutch weight

Insufficient horsepower or poor high
speed performance

1. Worn drive belt

2. Insufficient spring force of driven pulley

3. Worn roller

4. Driven pulley operation un-smoothly

8-2

To this chapter contents

Left Crankcase Cover

Left crankcase cover removal

Release the 2 clamp strips of left crankcase cover
ducts, and then remove the ducts.
Remove left crankcase cover. (9 bolts)
Remove 2 dowel pin and gasket.

Left crankcase cover install

Install left crankcase cover in the reverse
procedures of removal.

8. V-BELT DRIVING SYSTEM

Clamp strips

9 bolts

Dowel pins

Left cover plate

Dowel pins

Bearing setting plate

Drive shaft holder bearing

Left cover plate gasket

8-3

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8. V-BELT DRIVING SYSTEM

Left crankcase cover inspection

Remove 2 bolts to remove left crankcase cover
bearing setting plate.

Check bearing on left crankcase cover.
Rotate bearing’s inner ring with fingers.
Check if bearings can be turned in smooth and
silent, and also check if bearing outer ring is
mounted on cover tightly.

2 bolts

9 bolts

If bearing rotation is uneven, noising, or loose
bearing mounted, then replace it.

8-4

To this chapter contents

Drive Belt

Removal

Remove left crankcase cover.
Hold drive face with universal holder, and remove
nut and drive face.

Special Tool：universal holder

Hold clutch outer with universal holder, and
remove nut, bearing stay collar and clutch outer.

Caution

y Using special service tools for tightening or

loosening the nut.

8. V-BELT DRIVING SYSTEM

Universal holder

Universal holder

Bearing stay collar

y Fixed rear wheel or rear brake will damage

reduction gear system.

Push the drive belt into belt groove as diagram
shown so that the belt can be loosened, and then
remove the driven pulley.
Remove driven pulley. Do not remove drive belt.
Remove the drive belt from the groove of driven
pulley.

Inspection

Check the drive belt for crack or wear. Replace it
if necessary.
Measure the width of drive belt as diagram shown.

Service Limit: 22.5 mm

Replace the belt if exceeds the service limit.

Caution

y Using the genuine parts for replacement.
y The surfaces of drive belt or pulley must be

free of grease.

y Clean up all grease or dirt before installation.

Belt tooth

Width

8-5

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8. V-BELT DRIVING SYSTEM

Installation

Caution

z Pull out driven face to avoid it closing.
z Cannot oppress friction plate comp in order

to avoid creates the distortion or the
damage.

Install drive belt onto driven pulley.

Install the driven pulley that has installed the belt
onto drive shaft.
On the drive belt another end to the movable drive
face.

Install the clutch outer and bearing stay collar.

Driven face

Universal holder

Bearing stay collar

Hold the clutch outer whit universal holder, and
then tighten nut to specified torque value.

Torque value: 5.0~6.0kgf-m

Install the drive face, washer and drive face nut.
Hold drive face with universal holder, and then
tighten nut to specified torque value.

Torque value: 8.5~10.5kgf-m

Universal holder

8-6

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Drive Face

Removal

Remove left crankcase cover.
Hold drive face with universal holder, and then

remove drive face nut.
Remove drive face and drive belt.

Remove movable drive face comp and drive face
boss from crankshaft.

Remove ramp plate.

Crankshaft

8. V-BELT DRIVING SYSTEM

Universal holder

Movable drive face

Drive face boss

Ramp plate

Remove weight rollers from movable drive face.

Movable drive face

Weight roller

8-7

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8. V-BELT DRIVING SYSTEM

Inspection

The weight rollers are to press movable drive face
by means of centrifuge force.
Thus, if weight rollers are worn out or damaged,
the centrifuge force will be affected.
Check if rollers are worn or damaged. Replace it
if necessary.
Measure each roller’s outer diameter. Replace it if
exceed the service limit.

Service limit: 19.0 mm
Weight: 17.2g

Check if drive face boss is worn or damaged and
replace it if necessary.
Measure the outer diameter of movable drive face
boss, and replace it if it exceed service limit.

Service limit: 29.962 mm

Weight roller

Movable drive face

Drive face boss

Measure the inner diameter of movable drive face,
and replace it if it exceed service limit.

Service limit: 30.060 mm

Reassembly/installation
Install weight rollers.

Caution

The weight roller two end surfaces are not
certainly same. In order to lengthen the roller
life and prevented exceptionally wears the
occurrence, Please end surface of the closure
surface counter clockwise assembles onto
movable drive face.

Install ramp plate.

Weight roller

Ramp plate

Closure surface

8-8

Guide collar

To this chapter contents

With 4~5g grease spreads wipes drives in the
movable drive face axis hole.
Install drive face boss.

Caution

The movable drive face surface has to be free of
grease. Clean it with cleaning solvent.

Install movable drive face comp. onto crankshaft.

Driven pulley installation

Press drive belt into pulley groove, and then pull
the belt onto drive shaft.

Install drive face, washer and nut.

8. V-BELT DRIVING SYSTEM

Movable drive face

Crank shaft

Press down

Drive belt

Drive face boss

Drive face boss

Caution

Make sure that two sides of pulley surfaces have
to be free of grease. Clean it with cleaning
solvent.

Hold drives face with universal holder.
Tighten nut to specified torque.

Torque value: 8.5~10.5kgf-m

Install left crankcase cover.

8-9

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8. V-BELT DRIVING SYSTEM

Clutch Outer/Driven Pulley

Disassembly

Remove drive belt, clutch outer and driven pulley.
Install clutch spring compressor onto the pulley
assembly, and operate the compressor to let the
wrench be installed more easily.

Caution

Do not press the compressor too much.

Hold the clutch spring compressor onto bench vise,
and then remove mounting nut with special service
tool.
Release the clutch spring compressor and remove
friction plate, clutch weight and spring from driven
pulley.

Remove seal collar from driven pulley.

Remove guide pin, guide pin roller, and movable
driven face, and then remove O-ring & oil seal
seat from movable driven face.

Clutch nut wrench

Movable driven face

Clutch spring compressor

Seal

Guide pin

Collar

Inspection
Clutch outer

Measure the inner diameter of clutch outer.
Replace the clutch outer if exceed service limit.

Service limit: 145.450 mm

O-ring

Inner
diameter

Guide pin

Guide pin roller

Clutch outer

8-10

To this chapter contents

Clutch lining

Measure each clutch weight thickness. Replace
it if exceeds service limit.

Service limit: 3.0 mm

Driven pulley spring

Measure the length of driven pulley spring.
Replace it if exceeds service limit.

Service limit: 97.4 mm

8. V-BELT DRIVING SYSTEM

Clutch lining

Clutch weight

Driven pulley

Check following items:

y If both surfaces are damaged or worn.
y If guide pin groove is damaged or worn.

Replace damaged or worn components.
Measure the outer diameter of driven face and the
inner diameter of movable driven face. Replace it
if exceeds service limit.

Service limit: Outer diameter 40.93 mm

Inner diameter 41.07 mm

Driven Pulley Bearing Inspection

Check if the inner bearing oil seal is damage.
Replace it if necessary.
Check if needle bearing is damage or too big
clearance. Replace it if necessary.
Rotate the inside of inner bearing with fingers to
check if the bearing rotation is in smooth and silent.
Check if the bearing outer parts are closed and
fixed. Replace it if necessary.

Free length

Driven face

Movable driven face

Guide pin groove

Needle bearing

Outer ball bearing

8-11

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8. V-BELT DRIVING SYSTEM

Clutch weight Replacement

Remove snap ring and washer, and then remove
clutch weight and spring from driving plate.

Caution

Some of models are equipped with one mounting
plate instead of 3 snap rings.

Check if spring is damage or insufficient elasticity.

Check if shock absorption rubber is damage or
deformation. Replace it if necessary.
Apply with grease onto setting pins.

Spring

Clutch weight

Shock absorption rubber

Driving plate

Snap ring

Setting pin

Install new clutch weight onto setting pin and then
push to the specified location.
Apply with grease onto setting pins.
But, the clutch block should not be greased. If so,
replace it.

Caution

Grease or lubricant will damage the clutch weight
and affect the block’s connection capacity.

Install the spring into groove with pliers.

Shock absorption rubber

Clutch weight

Spring

8-12

To this chapter contents

Install snap ring and mounting plate onto setting
pin.

Replacement of Driven Pulley Bearing

Remove inner bearing.

Caution

y If the inner bearing equipped with oil seal on

side in the driven pulley, then remove the oil

seal firstly.

y If the pulley equipped with ball bearing, it has to

remove snap ring and then the bearing.

8. V-BELT DRIVING SYSTEM

Snap ring

Outer bearing

Clipper

Inner needle
bearing

Remove snap ring and then push bearing forward
to other side of inner bearing.
Place new bearing onto proper position and its
sealing end should be forwarded to outside.
Apply with specified oil.

Install new inner bearing.

Caution

y Its sealing end should be forwarded to outside

as bearing installation.

y Install needle bearing with hydraulic presser.

Install ball bearing by means of hydraulic

presser.

Snap ring

Snap ring

Outer bearing

Bearing end

Install snap ring into the groove of drive face.
Align oil seal lip with bearing, and then install the
new oil seal (if necessary).

Inner bearing

8-13