Sym Fiddle II 125 AW12W, Fiddle II 125, AW12W Service Manual

SERVICE MANUAL

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Fiddle II 125 – AW12W

SYM FORWARD

This service manual contains the technical data of each component
inspection and repair for the SYM series motorcycle. 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 motorcycle are different from that of the
photos, pictures shown in this manual, the actual vehicle shall prevail.
Specifications are subject to change without notice.

This manual that contains all data, illustration, indication and specifications
is based on current production information. SYM reserves the right to make
changes at any time without notice and without incurring any obligation
whatever. No part of this manual can be duplicated by any means without
written permission of SANYANG.

SERVICE DEPARTMENT

SAN YANG INDUSTRY CO., LTD.

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HOW TO USE THIS MANUAL SYM

This service manual describes basic information of different system parts and
system inspection & service for SYM series motorcycles. 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.
The third to the eleventh chapters cover engine and driving systems.
The twelfth to fifteenth chapters are contained the parts set of assembly
body.
The sixteenth chapter is electrical equipment.

The seventh chapter is for wiring diagram.
Please see index of content for quick having the special parts and system
information.

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SYM CONTENTS

CONTENTS

GENERAL INFORMATION/TROUBLE DIAGNOSIS...................................1

MAINTENANCE INFORMATION .................................................................2

LUBRICATION SYSTEM..............................................................................3

FUEL SYSTEM.............................................................................................4

ENGINE REMOVAL......................................................................................5

CYLINDER HEAD/VALVE............................................................................6

CYLINDER/PISTON......................................................................................7

"V" TYPE BELT DRIVING SYSTEM/KICK STARTER ARM .......................8

FINAL DRIVING MECHANISM.....................................................................9

A.C. GENERATOR/STARTING CLUTCH....................................................10

CRANKCASE/CRANKSHAFT .....................................................................11

BODY COVER..............................................................................................12

BRAKE SYSTEM..........................................................................................13

STEERING/FRONT WHEEL/FRONT SHOCK ABSORBER........................14

REAR WHEEL/SUSPENSION......................................................................15

ELECTRICAL EQUIPMENT.........................................................................16

ELECTRICAL DIAGRAM .............................................................................17

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MECHANISM ILLUSTRATIONS SYM

Light/starter switch

Front disk brake

Exhaust muffler

Ignition switch

Gear oil draining
bolt

Battery/Fuse/CDI

Front brake lever

Rea

r

brake lever

Ai

r

cleane

r

Gearoil filling
bolt

Oil level

Tail light

Front turn
signal light

Fuel tank / Fuel unit

High&Low beam/Seat
open/turn signal/horn

Head light/
Position light

Rear turn
signal light

Engine number/engine
oil draining bolt

Ignition coil

Frame numbe

r

Meter

A.C. Generator

Start magnetic switch

Horn/REG.REC

RR. turning
signal light

Tail light

Front turn
signal light

Winker relay

Engine control
switch

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SPECIAL TOOL

1

ITEM: R/L CRANKCASE DISASSEMBLE TOOL

NO：SYM-1120100

PURPOSE: DISASSEMBLE CRANKCASE

ITEM: CRANK PULLER

NO：SYM-1130000

PURPOSE: INSTALL CRANKCASE

ITEM: OUTER BEARING PULLER

NO：SYM-6204010

PURPOSE: REMOVE THE BEARING

ITEM: ACG FLYWHEEL PULLER

NO：SYM-3110A00
PURPOSE:

REMOVE ACG FLYWHEEL

ITEM: LOCK NUT PULLER

NO：SYM-9020100

PURPOSE:

REMOVE THE LOCK NUT

ITEM: UNIVERSAL HOLDER

NO：SYM-2210100
PURPOSE:HOLD THE MDF/CLUTCH OUTER

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SPECIAL TOOL

2

ITEM: CLUTCHSPRING COMPRESSOR

NO：SYM-2301000
PURPOSE:DISASSEMBLE THE CLUTCH

ITEM: CLUTCH NUT WRENCH

NO：SYM-9020200
PURPOSE:LOOSE THE CLUTCH NUT

ITEM: GY6 STARTER GEAR PULLER

NO：SYM-2822100-GY6

PURPOSE:REMOVE THE

STARTER GEAR

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-1

SYMBOLS AND MARKS....................1-1

GENERAL SAFETY............................1-2

SERVICE PRECAUTIONS.................1-3

SPECIFICATIONS..............................1-9

TORQUE VALUES (ENGINE)..............1-10

TORQUE VALUES (FRAME)...............1-11

TROUBLES DIAGNOSIS..................... 1-12

LUBRICATION POINTS....................... 1-16

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

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

Caution

Means that equipment damages may result if procedures are not followed.

Engine oil

Limits to use SAE 10W-30 API SH/CD class oil. Warranty will not cover the
damage that caused by not apply with the limited engine oil.

Grease

King Mate G-3 is recommended.

Locking sealant

Apply sealant, medium strength sealant should be used unless otherwise
specified.

Oil seal

Apply with lubricant.

Renew

Replace with a new part before installation.

Brake fluid

Use recommended brake fluid DOT3 or WELLRUN brake fluid.

Special tools

Special service tools.

Correct

Meaning correct installation.

Wrong

Meaning wrong installation.

Indication

Indication of components.

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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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

1-2

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

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

Used engine oil

Caution

Hot components

Caution

Battery

Caution

Brake shoe

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

Caution

Brake fluid

Caution

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

 Battery emits explosive gases; flame is

strictly prohibited. Keep 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, 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.

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

Prolonged contact with used engine oil (or
transmission oil) may cause skin cancer
although it might not be verdict.

Inhaling asbestos dust may cause disorders
and cancer of the breathing system.

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 brake fluid beyond reach of children.

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.

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-3

SERVICE PRECAUTIONS

 Always use with SANYANG genuine parts

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

 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.

 When servicing this motorcycle, 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.

 Clean the outside of the parts or the cover

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

 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.

 Never bend or twist a control cable to prevent

stiff control and premature worn out.

 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.

 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.

 Store complex components such as

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

 Note the reassemble position of the important

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

 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/TROUBLE DIAGNOSIS SYM

1-4

 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.

 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.

 When oil seal is installed, fill the groove with

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

 Remove residues of the old gasket or sealant

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

 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.

 Rubber and plastic boots should be properly

reinstalled to the original correct positions as
designed.

 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.

Manufacturer's
name

Groove

Clamp

Connector

Boots

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-5

 Lubricate the rotation face with specified

lubricant on the lubrication points before
assembling.

 Check if positions and operation for installed

parts is in correct and properly.

 Make sure service safety each other when

conducting by two persons.

 Note that do not let parts fall down

 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.

 After service completed, make sure all

connection points is secured. Battery
positive (+) cable should be connected firstly.
And the two posts of battery have to be
greased after connected the cables.

 Make sure that the battery post caps are

located in properly after the battery posts had
been serviced.

 If fuse burned, it has to find out the cause

and solved it. And then replace with
specified capacity fuse.

capacity
verification

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

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 When separating a connector, it locker has to

be unlocked firstly. Then, conduct the
service operation.

 Do not pull the wires as removing a

connector or wires. Hold the connector
body.

 Make sure if the connector pins are bent,

extruded or loosen.

 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.

 Check if the connector is covered by the twin

connector boot completely and secured
properly.

 Before terminal connection, check if the boot

is crack or the terminal is loose.

 Insert the terminal completely. Check if the

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

 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.

 Wire band and wire harness have to be

clamped secured properly.

 Do not squeeze wires against the weld or its

clamp.

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-7

 Do not let the wire harness contact with

rotating, moving or vibrating components as
routing the harness.

 Keep wire harnesses far away from the hot

parts.

 Route wire harness to avoid sharp edges or

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

 Route harnesses so that they neither pull too

tight nor have excessive slack.

 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.

 Secure the rubber boot firmly as applying it

on wire harness.

 Never use wires or harnesses which

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

 Never clamp or squeeze the wire harness as

installing other components.

Do not touch it.

Do not extend
it too much.

Please do not clip or
squeeze the wire.

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

1-8

 Do not let the wire harness been twisted as

installation.

 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.

 Before operating a test instrument, operator

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

 With sand paper to clean rust on connector

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

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

Clean rust.

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-9

SPECIFICATIONS

MAKER SANYANG MODEL ALA125CC (AW12W-6)

Overall Length 1870mm Front TELESCOPIC FORK

Overall Width 698 mm

Suspen

sion

System

Rear UNIT SWING

Overall Height 1325 mm Front 110/70-12 47J

DIMENSION

Wheel Base 1325mm

Tire

Specifi

cations

Rear 120/70-12 51J

Front 41kg

Rear 68kg

Front DISK (ø 190 mm)

Curb Weight

Total 109kg

Brake

System

Rear DRUM (ø 130 mm)

Passengers/

Weight

Two men/110 kg Max. Speed ＞92km/h

Front 85kg

Performa

nce

Climb Ability ＞28°

Rear 134kg Primary Reduction BELT

WEIGHT

Total Weight

Total 219kg

Secondary

Reduction

GEAR

Type

4-STROKE ENGINE

(OHC)

Clutch Auto centrifugal clutch

Installation and

arrangement

Vertical, below center,

incline 80°

Deceleration

equipment

Transmission C.V.T.

Fuel Required Unleaded gasoline Speedometer 0 ~ 140 km/h

Cycle/Cooling

4-stroke/forced air

cooled

Horn 93~112dB

Bore 52.4 mm Muffler Expansion & Pulse Type

Stroke 57.8 mm

Exhaust Pipe Position

and Direction

Right side, and

Backward

Cylinder

Number/Arran

gement

Single Cylinder

Lubrication System

Forced-circulation&

splashing

Displacement 124.6 cc

CO <2.0 g/km

Compression

Ratio

9.6 : 1 HC

<0.8 g/km

Max. HP 6.25KW/8000 rpm

Exhaust

Emission

NOx <0.15 g/km

EURO3

Max. Torque 8.33N.m /6500 rpm

Air Filtration Paper filter

Ignition C.D.I.

Noise Emission < 77dB

ENGINE

Starting System Kick & electrical starter

Engine Weight(dry

weight)

30kg

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

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TORQUE VALUES (ENGINE)

ITEM Q'TY

THREAD DIA

(mm)

TORQUE

VALUE(Kg-m)

REMARKS

A.C. generator fixing bolts 2 6 0.8~1.2
Pulse generator hex bolts 2 5 0.35~0.5
Gear oil filling bolt 1 8 1.0~1.4
Oil pump flat bolts 2 6 0.8~1.2
Crankcase flange bolts 2 6 0.8~1.2
Oil pump drive sprocket nut 1 6 0.8~1.2
Cylinder/cylinder head two-ends

bolts

4 8 0.7~1.1 Tighten to crankcase

Oil pump drive separator bolts 2 6 0.8~1.2
Cam holder nuts 4 8 1.8~2.2
Start clutch lock nut 1 22 9.0~10.0
Camshaft chain adjuster bolts 2 6 0.8~1.2
Cylinder head bolts 3 6 0.8~1.2
Cylinder head cover bolts 4 6 0.8~1.2
Right crankcase cover bolts 10 6 0.8~1.2
Flywheel nut 1 12 5.0~6.0
Shroud A/B tapping screws 3 5 0.8~1.2
Cooling fan bolts 4 6 0.8~1.2
Cooling fan cover 2 6 0.8~1.2
Transmission(Gear box) bolts 7 8 1.8~2.2
RR. brake arm bolt 1 6 0.8~1.2
Crankcase draining plug bolt 1 12 3.5~4.5
Drive pulley nut 1 12 5.0~6.0
Drive face nut 1 12 5.0~6.0
Start motor bolts 2 6 0.8~1.2
Left crankcase cover bolts 10 6 0.8~1.2
Carburetor nuts 2 6 0.8~1.2
A.I. fixing hex cap nuts 2 6 0.8~1.2
Valve adjustment fixing nuts 2 5 1.0~1.5 Apply oil to thread
Gear oil draining plug bolt 1 12 3.5~4.5
Camshaft chain tensioner pivot 1 6 0.8~1.2 Hex socket bolt
Spark plug 1 10 1.0~1.4
Engine oil strainer cap 1 30 1.0~2.0
Kick starter arm bolt 1 6 0.8~1.2
Exhaust pipe bolts 2 8 3.0~3.6
Exhaust pipe connecting nuts 2 6 1.0~1.4

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-11

TORQUE VALUES (FRAME)

ITEM Q'TY

THREAD DIA

(mm)

TORQUE

VALUE(Kg-m)

REMARKS

Mounting bolt for steering
handlebar

1 10 4.0~5.0

Mounting nut for steering rod 1 25.4 1.0~2.0
Cone seat for steering rod 1 25.4 0.2~0.3

Front wheel axle nut 1 12 5.0~7.0
Rear wheel axle nut 1 16 11.0~13.0

Wheel hub/rim mounting
nuts

8 8 2.8~3.2

Speedometer cable locking
screw

1 5 0.15~0.3

Front shock absorber
mounting bolts

4 8 2.4~3.0

Rear shock absorber upper
connection bolt

1 10 3.5~4.5

Rear shock absorber lower
connection bolt

1 8 2.4~3.0

Brake lever bolts 2 6 0.8~1.2
Front brake hose bolts 2 10 3.3~3.7

Front brake air-bleeding
valve

1 6 0.8~1.0

Front brake disc mounting
bolts

4 10 4.0~4.5

Front brake clipper mounting
bolts

2 10 3.1~3.5

Drum brake arm bolts
(front/rear)

2 6 0.8~1.2

Engine suspension bolts 2 10 4.5~5.5 On frame side
Engine connection bolt 1 10 4.5~5.5 On engine side

Main stand nut 1 10 3.5~4.5
Foot-starting lever bolt 1 6 1.6~1.8
Air cleaner bolts 2 6 1.0~1.4

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

5mm bolt、nut

0.45~0.60kgf-m

3mm screw

0.05~0.08kgf-m

6mm bolt、nut

0.80~1.20kgf-m 4mm screw 0.10~0.15kgf-m

8mm bolt、nut

1.80~2.50kgf-m 5mm screw 0.35~0.50kgf-m

10mm bolt、nut

3.00~4.00kgf-m

6mm screw、SH nut

0.70~1.10kgf-m

12mm bolt、nut

5.00~6.00kgf-m

6mm bolt、nut

1.00~1.40kgf-m

8mm bolt、nut

2.40~3.00kgf-m

10mm bolt、nut

3.50~4.50kgf-m

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

1-12

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

No fuel is supplied to
carburetor

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

perform cylinder
compression pressure test.

Check if sparks Weak sparks, no spark

at all

Low compression
pressure or no pressure

Re-start by following the
starting procedures

No ignition

There are some signs of
ignition, nut engine can
not be started

Remove the spark plug
again and check it.

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

Dry spark plug

Wet spark plug

Blowing in normal

Blowing clogged

1. No fuel in fuel tank

2. Check if the pipes, fuel tank to
carburetor and intake vacuum,
are clogged.

3. Float valve clogged

4. Lines in fuel tank evaporation
system clogged

5. Malfunction of fuel pump

6. Loosen or damaged fuel pump
vacuum hose

7. Fuel filter clogged

1. Malfunction of spark plug

2. Spark plug foul

3. Malfunction of CDI set

4. Malfunction of AC generator

5. Ignition coil is in open or short
circuit

6. Ignition coil leads open or short
circuit

7. Malfunction of main switch

1. Piston ring seized

2. Malfunction of cylinder valves

3. Worn cylinder and piston ring

4. Cylinder gasket leak

5. Sand hole in compression parts

1. Malfunction of throttle valve
operation

2. Air sucked into intake manifold

3. Incorrect ignition timing

1. Fuel level in carburetor too high

2. Malfunction of throttle valve
operation

3. Throttle valve opening too wide

1. Malfunction of automatic by­starter

cylinder compression
pressure normal

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-13

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.

Engine speed can not be
increased.

Check ignition timing
(Using ignition lamp)

Check cylinder compression
pressure (using compression
pressure gauge)

Ignition timing correct

Incorrect ignition timing

Compression pressure correct

No compression

Check if carburetor jet is
clogged

No clogged Clogged

Remove spark plug

Check if engine over heat

No foul or discoloration Fouled and discoloration

No knock

Knock

1. Air cleaner clogged

2. Poor fuel supply

3. Lines in fuel tank evaporation
system clogged

4. Exhaust pipe clogged

5. Fuel level too low in carburetor

6. Fuel nozzle clogged in

1. Malfunction of CDI

2. Malfunction of AC alternator

1. Cylinder & piston ring worn out

2. Cylinder gasket leaked

3. Sand hole in compression parts

4. Valve deterioration

5. Seized piston ring

1. Remove foreign

1. Remove dirt

2. Incorrect spark plug heat range

1. Piston and cylinder worn out

2. Lean mixture

3. Poor fuel quality

4. Too much carbon deposited in
combustion chamber

5. Ignition timing too advanced

6. Poor circuit on the cooling
s

y

stem

Normal

Engine overheat

Continually drive in
acceleration or high speed

1. Too much carbon deposited in
combustion chamber

2. Lean mixture

3. Poor fuel quality

4. Ignition timing too advanced

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

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

D. Engine runs sluggish (High speed)

Check ignition timing

(using ignition lamp)

Good spark Poor

No air sucked Air sucked

Good Poor

Abnormal

Air sucked through

carburetor gasket

Adjust the air screw of
carburetor

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

Normal

Check and adjustment Fault condition Probable causes

Check for fuel supplying
system in automatic fuel cup

Check if carburetor clogged

1. Incorrect ignition timing (malfunction
of CDI or AC alternator)

1. Rich mixture (loosen the screw)

2. Lean mixture (tighten the screw)

1. Poor heat insulation gasket

2. Carburetor lock loose

3. Poor intake gasket

4. Poor carburetor O-ring

5. Vacuum hose crack

1. Spark plug fouled

2. Malfunction of CDI

3. Malfunction of AC generator

4. Malfunction of ignition coil

5. Open or short circuit in spark plug
leads

6. Malfunction of main switch

1. Insufficient fuel in fuel tank

2. Fuel filter clogged

3. Restricted fuel tank vent

Good

Poor

Check and adjustment Fault condition Probable causes

Check ignition timing

1. Malfunction of CDI

2. Malfunction of AC alternator

Normal Abnormal

No clogged Clogged

1. Cleaning

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SYM 1. GENERAL INFORMATION/TROUBLE DIAGNOSIS

1-15

E. CLUTCH, DRIVING AND DRIVING PULLEY

1. Clutch ling spring broken

2. Clutch outer stick with clutch balance weights

3. Connection parts in clutch and shaft worn out
or burned

Engine can be started but
motorcycle can not be moved.

FAULT CONDITIONS PROBABLE CAUSES

1. Driving belt worn out or deformation

2. Driving disk damaged

3. Driving pulley spring broken

4. Clutch ling broken

5. Driving slide-shaft gear groove broken

6. Transmission gear damaged

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

Poor initial driving ( Poor
climbin

g p

erformance

)

1. Driving belt worn out or deformation

2. Balance weight roller worn out

3. Driving sliding gear shaft worn out

4. Driving disk spring deformation

5. Driving sliding gear shaft worn out

6. Greased in driving belt and sliding gear.

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1. GENERAL INFORMATION/TROUBLE DIAGNOSIS SYM

1-16

LUBRICATION POINTS

A

cceleration cable/ Front & rear

brake lever pivot

Steering shaft bearing

Speedometer gear /
Front wheel bearing

Side stand shaft

Main stand shaft

Rear wheel bearing

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SYM 2. MAINTENANCE INFORMATION

2-1

PRECAUTIONS IN OPERATION.......2-1

PERIODICAL MAINTENANCE SCHEDULE........2-2

LUBRICATION SYSTEM....................2-3

FUEL SYSTEM...................................2-4

AIR CLEANER....................................2-5

THROTTLE VALVE OPERATION......2-5

VALVE CLEARANCE INSPECTION & ADJUSTMENT ......2-6

CARBURETOR IDLING SPEED ADJUSTMENT .2-7

IGNITION SYSTEM/SPARK PLUG ..2-8

CYLINDER COMPRESSION PRESSURE

.2-9

DRIVING SYSTEM.............................2-9

STEERING SYSTEM .........................2-10

SUSPENSION SYSTEM ....................2-10

FRONT DISK BRAKE SYSTEM.........2-11

DRUM BRAKE SYSTEM....................2-13

WHEEL/TIRE......................................2-14

BATTERY...........................................2-15

HEADLIGHT ADJUSTMENT..............2-15

NUTS、BOLTS TIGHTEN..................2-15

PRECAUTIONS IN OPERATION

Specification

Main 5000 c.c.

Fuel Tank Capacity

auxiliary 1500 c.c.
capacity 800 c.c.

Engine Oil

change 750 c.c.

capacity 120 c.c.

Transmission Gear oil

change 110 c.c.

Clearance of throttle valve 2~6 mm
Spark plug A7RC Gap: 0.6~0.7 mm
“F” Mark in idling speed

Before TDC 13º±3º /1800 rpm below
Full timing advanced Before TDC 26º / 8000 rpm
Idling speed 1700±100 rpm
Cylinder compression pressure 13 kg/cm²
Valve clearance: IN/EX

0.12±0.02/ 0.12±0.02 mm

Tire dimension front / rear 110/70-12 47J / 120/70-12 51J

single Front: 1.75 kg/cm² rear: 2.00 kg/cm²

Tire pressure (cold)

Two persons Front: 1.75 kg/cm² rear: 2.25 kg/cm²

Battery capacity 12V 7Ah (MF battery)
Play of drum brake lever 10~20 mm

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2. MAINTENANCE INFORMATION SYM

2-2

PERIODICAL MAINTENANCE SCHEDULE

Mainte
nance

Code

Item Initial 300KM

1 Month

Every1000KM

3 month

Every3000KM

6 month

Every6000KM

1 year

Every12000K

M

1

☆Air cleaner

I C C R

2

☆2nd air jet leaner

I C C R

3

☆Fuel filter

I I R

4

☆Oil filter

C C C

5

☆Engine oil change

R

Replacement for every 1000km

6 Tire pressure

I I

7 Battery inspection

I I

8 Brake & free play check

I I

9 Steering handle check

I I

10 Cushion operation check

I I

11 Every screw tightening check

I I

12 Gear oil check for leaking

I I

13

☆Spark plug check or change

I I R

14

☆Gear oil change

R

Replacement for every 5000km

15 Frame lubrication

L

16 Exhaust pipe

I I

17

☆Ignition timing

I I

18

☆Emission check in Idling

A I

19

☆Throttle operation

I I

20

☆Engine bolt tightening

I I

21

☆CVT driving device (belt﹞

I R

22

☆CVT driving device (roller)

C

23 Lights/electrical equipment/mutli-meters

I I

24 Main/side stands & springs

I I

25 Fuel pipes

I I

27 Cam chain

I I

28

☆Valve clearance

I A

29

☆Crankcase vapor control System

I C

30

☆Crankcase blow-by over-flow pipe

I

Replacement for every 2000km

31

☆2nd air jet system

I I C

32

☆vapor control system

I

Code: I ~ Inspection, cleaning, and adjustment R ~ Replacement C ~ Cleaning (replaced if necessary) L ~ Lubrication

Have your motorcycle checked, adjusted, and recorded maintenance data periodically by your SYM Authorized Dealer to
maintain the motorcycle 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. These marks “☆” in the schedule are emission control items. According to EPA regulations, these items

must be perform normally periodical maintenance following the use r manual instructions. They are
prohibited to be adjusted or repaired by unauthorized people. Otherwise, SYM is no responsible for the
charge.

2. Clean or replace the air cleaner element more often when the motorcycle is operated on dusty roads or in the
Heavily- polluted environment.

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

4. 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.

c. Replace worn out pistons, cylinder head.

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SYM 2. MAINTENANCE INFORMATION

2-3

LUBRICATION SYSTEM

Engine Oil Capacity

Caution

Remove dipstick to check the oil level. If oil
level is below the lower limit mark, add oil to
the specified upper limit mark.

Oil change

Shut off the engine and remove dipstick.
Remove the oil drain plug on the bottom-left
of crankcase to drain oil.
After draining out oil, clean oil plug and its
+-gasket and reinstall. Replace the gasket if
it is damaged.
Torque value: 3.5~4.5 kgf-m

Caution

Add oil to the specified capacity.
Oil Viscosity: SAE 10W-30, recommended
using King-Mate serial oil.

Engine oil capacity:
Disassembly: 850cc
Change: 750cc

When checking for oil leak, run the engine at
idle speed for a few minutes, then check oil
capacity with dipstick.

Cleaning the oil strainer

Drain oil from engine, remove the strainer
cover, spring and strainer.
If there is an accumulation on the screen,
wash it off with suitable solvent
(recommended using compressed air).
Check O-ring for damage, replace if
necessary.
Reinstall strainer, spring, O-ring and strainer
cover.

Torque value: 1.0~2.0 kgf-m



The vehicle must be parked on a level
ground when checking oil capacity.

 Run the engine for 2-3 minutes then stop,

wait about 2-3 more minutes allowing
engine oil to settle before checking the oil
level.

Warm up the engine. This will make the oil
flow out easily.

Oil drain plug

Dipstick

strainer cove

r

oil straine

r

spring

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2. MAINTENANCE INFORMATION SYM

2-4

Gear Oil
Inspection

Check gear oil if leaking.
Park the motorcycle with main stand on flat
level place.
Turn off engine and remove the gear oil
draining plug.
Place a measurement cup under the draining
hole.
Remove the oil drain plug and drain gear oil
into a measurement cup.
Check gear oil if enough.

Replacement

At first, remove the gear oil refilling bolt, and
then remove the draining plug.

Install the draining plug after drained oil out.

Torque value: 3.5~4.5 kgf-m

Caution

Fill out gear oil to specified quantity from the
engine oil filling hole.
Install the oil filling bolt.

Torque value: 1.0~1.4 kgf-m
Quantity: 100 c.c.

Recommended: King-Mate HYPOID GEAR
OIL ( #140 ).

Fuel System

Fuel Pipe

Remove luggage box, rear center cover,
body cover, and rear fender, as well as front
inner box.
Check all pipes, and replace it when they are
deterioration, damage or leaking.

Warning

Fuel filter

Remove the fuel tank.
Remove fuel pipe from the fuel filter.
Replace the fuel filter with new one.
Install the fuel filter.

Caution

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

Inspect if washer is in good condition.
Replace it with new one if it was deformed
or damaged.

The arrow on the fuel filter means the flow
direction of fuel and check it if leaking after
installation.

Gear oil refilling bolt

Gear oil draining plug

Fuel filte

r

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SYM 2. MAINTENANCE INFORMATION

2-5

AIR CLEANER

Element

Remove 6 screws from the air cleaner cover.
Remove element of air cleaner (2 screws).
Check the element if dirt or damaged.
Replace it with new one if dirt or damaged.

Caution

THROTTLE VALVE OPERATION

Have a wide open of throttle valve as handle
bar in any position and release it to let back
original (full closed) position.
Check handle bar if its operation is smooth.
Check throttle valve cable and replace it if
deteriorated, twisted or damaged.
Lubricate the cable if operation is not
smooth.
Measure handle bar free play in its flange
part.

Free play：2~6 mm

Adjustment can be done in either ends.
Secondary adjustment is conducted from top
side.
Remove rubber boot, loosen fixing nut, and
then adjust it by turning the adjustment nut.

 Air cleaner element contains a paper

made filter so do not try to clean it.

 Make sure that the air cleaner cover had

been installed properly after installation.

2~6 mm

Fixing nut

Adjustment nut

Rubber boot

screws×2

Air cleaner element

screws×6

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2. MAINTENANCE INFORMATION SYM

2-6

Primary adjustment is conducted from button
side.
Loosen fixing nut, and adjust by turning the
adjustment nut.
Tighten the fixing nut, and check
acceleration operation condition.

Caution

VALVE CLEARANCE ADJUSTMENT

Caution

Remove luggage box and front center cover.
Remove the left body cover & left side cover.
Remove cylinder head cap.
Remove the ignition timing check hole on the
cooling fan cover.
With “T” type wrench, turn crankshaft in
clockwise motion so that mark (“T”) on the
generator flywheel aligns with the mark on
the crankshaft, and camshaft is at TDC
position also as same as level of cylinder
head top-end. A single hole on camshaft
sprocket is forward to up. (Piston is at TDC
position in the compression stroke.)

Caution

When always riding in rainy area or full
throttle position, maintenance period must
be shorted. The deposits can be seen in
the transparent section of draining hose.

Checks and adjustment must be performed
when engine is cold (below 35℃).

The crankshaft can not be rotated in
counter-clockwise to prevent from damage
so that valve clearance can not be
measured.

Ignition timing mark

TDC mark

Inspection hole

Adjustment nut

Fixing nut

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SYM 2. MAINTENANCE INFORMATION

2-7

VALVE CLEARANCE INSPECTION
AND ADJUSTMENT

Check & adjust valve clearance with feeler
gauge.

Valve clearance (IN/EX):

0.12±0.02/0.12±0.02 mm

Loosen fixing nut and turn the adjustment
nut for adjustment.

Caution

CARBURETOR IDLE SPEED
ADJUSTMENT

Caution

Park the motorcycle with main stand and
warn up engine.
Open the carburetor cover from the luggage
box.
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 idle speed adjustment screw and
let engine runs in 1700±100 rpm.

3. Insert the exhaust sampling muffler 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.

EXHAUST EMISSION(EURO3):

CO＜2.0g/km
HC＜0.8g/km
NOX＜0.15g/km

It has to make sure that valve-rocker arm is
be adjusted to standard level when
adjusting it, and re-check the valve
clearance after tightened the fixing nut.



Inspection & adjustment for idle speed
have to be performed after all other parts
in engine that needed adjustment have
been adjusted.

 Idle speed check and adjustment have to

be done after engine is being warm up
(around 10 minutes).

Throttle valve stopper screw

Ignition coil cable

Air adjustment screw

Feeler gauge

Fixing nut

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2. MAINTENANCE INFORMATION SYM

2-8

IGNITION SYSTEM

Ignition timing

Caution

Remove ignition timing hole cap located on
the cooling fan cap, or remove the cooling
fan cap.
Check ignition timing with ignition light.
Start engine and set engine idle speed in
1700±100 rpm, and if the mark aligns with
the “F”, then it means that ignition timing is
correct.
Increase engine speed to 8000 rpm to check
ignition timing advance. If the detent aligns
with advance mark “װ”, then it means ignition
timing advance is in functional. If not,
check CDI set, pulse flywheel, and pulse
generator. Replace these components if
malfunction of these parts are found.

SPARK PLUG

Appointed spark plug: A7RC

Remove luggage box.
Remove center cover.
Remove spark plug cap.
Clean dirt around the spark plug hole.
Remove spark plug.
Measure spark plug gap.

Spark plug gap: 0.6~0.7 mm

Carefully bend ground electrode of the plug
to adjust the gap if necessary.
Screw the park plug into the plug hole with
hands, then tighten the plug with a wrench to
prevent from damaging the spark plug's
thread.

Torque value: 1.0~1.2 kgf-m

Connect spark plug cap.

C.D.I ignition system is set by manufacturer
so it can not be adjusted.
Ignition timing check procedure is for
checking whether C.D.I. function is in normal
or not.

Ignition light

F mark

0.6~0.7mm

Side electrode

Center electrode

Spark plug

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SYM 2. MAINTENANCE INFORMATION

2-9

CYLINDER COPMRESSION PRESSURE

Warn up engine and then turnoff the engine.
Remove the luggage box and the center
cover.
Remove spark plug cap and spark plug.
Install compression gauge.
Full open the throttle valve, and rotate the
engine by means of stepping the
kick-starting lever.

Caution

Compression pressure: 13 Kg/cm²

Check following items if the pressure is too
low:

 Incorrect valve clearance
 Valve leaking
 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.

DRIVING SYSTEM

DRIVING BELT

Remove left side cover.
Remove mounting bolt located under air
cleaner.
Remove 9 bolts of the engine left crankcase.
Remove the left crankcase 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: above 18.5 mm

Clutch pad

Start the motorcycle and gradually increase
throttle valve openness to check clutch pad
operation.
If the motorcycle moves with shaking, then
check its clutch pad for wearing. Replace it
if necessary.

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

Gear teeth

Width

Cylinder
pressure
gauge

Clutch

Clutch pad

Spark plug

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2. MAINTENANCE INFORMATION SYM

2-10

STEERING SYSTEM

Caution

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

SUSPENSION SYSTEM

Warning

Front shock absorber

Hold front brake lever and press down the
front shock absorber for several times to
check its operation.
Hold front brake lever and push forward the
front shock absorber for several times to
check its locking status.
Check if it is scratched or leaking.
Replace damaged and non-repairable
components.
Tighten all nuts and bolts.

Rear Shock absorber

Press down the rear shock absorber for
several times to check its operation.
Check if it is scratched or leaking.
Replace damaged and non-repairable
components.
Park the motorcycle with main standard.
Start engine and let the rear wheel rotate
after increased engine rpm. Check engine
for any parts loose or shaking. Also check
the engine suspension bushing for wear out.
Replace the bushing if worn out.
Tighten all nuts and bolts.

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

 Do not ride the motorcycle with poor

shock absorber.

 Looseness, wear or damage shock

absorber will make poor stability and
driveability.

Rear Shock absorber

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SYM 2. MAINTENANCE INFORMATION

2-11

FRONT DISC BRAKE SYSTEM

BRAKE SYSTEM HOSE

Make sure the brake hoses for corrosion or
leaking oil, and also check brake system for
leaking.

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

FILLING OUT BRAKE FLUID

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

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



In order to maintain brake fluid in the
reservoir in horizontal position, do not
remove the cap until handle bar stop.

 Do not operate the brake lever after the

cap had been removed. Otherwise, the
brake fluid will spread out if operated the
lever.

 Do not mix non-compatible brake fluid

together.

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

Brake fluid cap

Low brake level

Transparent hose

Bubbles

Draining valve

Brake hose

Lower limit

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2. MAINTENANCE INFORMATION SYM

2-12

ADDED BRAKE FLUID

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

Caution

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

Remove the brake clipper bolt, and take out
the clipper.

Caution

Pry out the brake lining with a flat driver if
lining be clipped.

Remove brake lining bolt.
Take out the lining.

Caution

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

It is not necessary to remove brake hose
when replacing the brake lining.

Do not operate the brake lever after the
clipper removed to avoid clipping the brake
lining.

In order to maintain brake power balance,
the brake lining must be replaced with one
set.

Brake ling wear limit

Brake clipper

Brake disc

Brake

clipper bolt

Bolt

Brake lining

Brake fluid cap

Low limit

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SYM 2. MAINTENANCE INFORMATION

2-13

DRUM BRAKE SYSTEM

Front Brake Free Play: (Drum brake)

Measure free play of rear brake level at the
end of the lever.

Free play: 10-20 mm

Adjust the free play by turning the front brake
adjustment nut if necessary.

REAR BRAKE FREE PLAY: (DRUM
BRAKE TYPE)

Measure the free play of the front brake lever
at the end of the lever.

Free play: 10-20 mm

Adjust the free play by turning the front brake
adjustment nut if necessary.

BRAKE CONFIRAMTION

Caution



A

fter brake adjustment, it has to check
the brake operation to make sure the
front and rear wheel can be braked.

 Pull the brake lever, and make sure that

the wear limit marks of brake ling on the
both front & rear brake arm are closer
and touch to the “△” marks. If so,
replace the brake ling with new one.

10∼20mm

Adjustment nut

Increasing free
play

Decreasing free play

“△” mark

A

djustment nut

Increasing

free play

Decreasing

free play

“△”marks

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2. MAINTENANCE INFORMATION SYM

2-14

BRAKE LIGHT SWITCH

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

WHEEL/TIRE

Check if both front and rear tire pressure are
within specification.

Caution

Appointed tire pressure

Tire size Front tire Rear tire

Load for
single

1.75 2.00

Tire
pressure
as cold tire
(Kg/cm²)

Load for
two
persons

1.75

2.25

Appointed Tire
Front/Rear wheel:

120/70-12 47J/ 130/70-12 51J

Check if tire surface is ticked with nails,
stones or other materials.
Check if tire surface or wall for crack or
damaged, and replace it if necessary.
The tire tread depth can be checked by
visual inspection or depth gauge.
 Replace the tire if tire tread dent or

unusual wearing out.

 The tire should be replaced if the wear

limit mark (△) is in visible.

Measure tire thread depth from tire center
surface.
Replace the tire if the depth is not come with
following specification:

Front tire: 1.5 mm
Rear tire: 2.0 mm

Caution

Tire pressure check should be done as cold
tire.

Wear limit indictor

〝△〞mark

The wear limit marks (△) are located
around the tire wall even for inspection.

Brake light switch

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SYM 2. MAINTENANCE INFORMATION

2-15

BATTERY

Battery Removal

Remove the 4 screws on the floor panel.
Remove battery cap. (4 screws)

Battery cables removal:

1. At first, remove the negative “-” cable.

2. Then, remove the positive “+” cable.

3. Remove the battery.

If there is some rust on battery posts, clean it
with steel brush.
Install the battery in the reverse procedures
of removal.

Caution

HEADLIGHT ADJUSTMENT

Turn the headlight adjustment bolt. And
adjust the headlight beam height.
Then, tighten the adjustment bolt after the
beam height in proper position.

Caution

NUTS, BOLTS TIGHTENESS

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 (pipe)
clamps, and wire holders for security.

 To adjust the headlight beam follows

related regulations.

 Improper headlight beam adjustment will

make in coming driver dazzled or
insufficient lighting.

 If there is rust on the posts very serious,

spray some hot water on the posts.
Then, clean it with steel brush so that
can remove rust for more easily.

 Apply some grease on the posts after

rust removed to prevent from rust again.

Battery cover screws

Headlight adjustment bolt

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SYM 3. LUBRICATION SYSTEM

3-1

MECHANISM DIAGRAM....................3-1

OPERATIONAL PRECAUTIONS .......3-2

TROUBLE DIAGNOSIS......................3-2

ENGINE OIL.......................................3-3

CLEANING ENGINE OIL STRAINER...3-3

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

GEAR OIL ............................................3-7

MECHANISM DIAGRAM

Valve rocker
arm

Camshaft

Scoop lubrication

Forcedly lubrication

Forcedly
lubrication

Inner passage

Connecting rod

Oil pump

Oil strainer

Crankshaft

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3. LUBRICATION SYSTEM SYM

3-2

OPERATIONAL PRECAUTIONS

General Information

 This chapter contains maintenance operations for the engine oil pump, engine oil and

gear oil.

Specifications

Engine oil quantity Disassembly 850 c.c.

Replacement 750 c.c.

Oil viscosity SAE 10W-30 or equivalent

(Recommended King-Mate
serial oils)

Gear Oil Disassembly 110 c.c.

Replacement 100 c.c.

Oil viscosity of gear oil SAE 85W-140

(Recommended King-Mate
gear oil series SYM
HYPOID GEAR OIL)

unit : mm

Items Standard Limit

Inner rotor clearance

- 0.12

Clearance between outer

rotor and body

- 0.12

Oil pump

Clearance between rotor

side and body

0.05~0.10 0.20

Torque value

Engine oil drain plug 3.5~4.5kgf-m
Engine oil screen cover 1.0~2.0kgf-m
Gear oil drain bolt 3.5~4.5kgf-m
Gear oil filling bolt 1.0~1.4kgf-m
Oil pump drive sprocket nut 0.8~1.2kgf-m

TROUBLE DIAGNOSIS

Low engine oil level

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

Low Oil Pressure

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

Dirty oil

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

Oil viscosity

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SYM 3. LUBRICATION SYSTEM

3-3

ENGINE OIL

Turn off engine, and park the motorcycle in
flat ground with main stand.
Check oil level with oil dipstick after 3-5
minutes.
Do not rotate the dipstick into engine as
checking.
If oil level is nearly low level, fill out
recommended oil to upper level.

Oil Replacement

Caution

Place an oil pan under the motorcycle, and
remove oil strainer cap.
Make sure if the aluminum washer of the
draining bolt is damaged. If so, replace it
with new one.
Install the drain bolt and tighten it.

Torque value: 3.5~4.5 kgf-m

CLEANING ENGINE OIL STRAINER

Remove the oil strainer cap.
Remove oil strainer and spring.
Clean oil strainer (recommended using
compressed air to clean dirty foreign).
Check if the strainer and O-ring of the oil
strainer are broken. Replace with new one if
found.
Install the oil strainer and spring.
Install the oil strainer cap and tighten it.

Torque value: 1.0~2.0 kgf-m

Fill out oil to the oil filler (Oil viscosity SAE
10W-30) (Recommended King-Mate serial
oils).

Engine oil quantity: Replacement 750 c.c.

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

Oil

strainer cap

Dipstick

Oil drain plug

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3. LUBRICATION SYSTEM SYM

3-4

OIL PUMP

Oil Pump Removal

Remove the alternator (refer to chapter10).
Remove the engine right cover.
Remove the one-way clutch and starting
gear (1 nut).

Make sure that the pump axle can be rotated
freely.
Remove the oil pump cover (2 bolts), and
then the oil pump driving gear nut and the
gear and oil pump driver chain.
Remove oil pump body bolts (2 bolts).

Oil Pump Disassembly

Remove the screw on oil pump cover.
Disassemble the oil pump as illustration shown.

Right crankcase

Oil pump cover

Oil pump shaft

Inner rotor

Outer rotor

Starting gear

Right crankcase cover

Oil pump outer cover

Oil pump body

Oil pump driving gear

Starting clutch

Oil pump driving chain

Oil strainer

bolts

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SYM 3. LUBRICATION SYSTEM

3-5

Oil Pump Inspection

Check the clearance between oil pump body
and outer rotor.

Limit: below 0.12 mm

Check clearance between inner and outer
rotors.

Limit: below 0.12 mm

Check clearance between rotor side face
and pump body.

Limit: below 2.0 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 driving shaft.
Install the oil pump cover and fixing pin
properly and then tighten screw. (1 screw)

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3. LUBRICATION SYSTEM SYM

3-6

Oil Pump Installation

Install the oil pump (2 bolts).

Install oil pump driver chain and drive gear.

Install oil pump outer cover (2 bolts).

Install the starting gear and the alternator.
(Refer to chapter 10)

2 bolts

2 bolts

oil pump driver
chain

drive gear

oil pump outer cover

Start drive gear

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SYM 3. LUBRICATION SYSTEM

3-7

GEAR OIL

Oil Level Inspection

Park the motorcycle on flat ground with main
stand.
Turn off engine and remove both engine oil
filling bolt and oil draining bolt.

Remove gear oil filling hole bolt and place a
measurement cup under the draining plug.
Remove the oil draining plug and the pour
gear oil into the measurement cup.
Measure the gear oil quantity if within
standard value.
Add specified gear oil if the oil level too low.
Standard quantity: 110cc.
Replacement: 100 cc.

Gear Oil Replacement

Remove the gear oil filling hole bolt and its
draining plug and then drain oil completely.
Install the draining plug and tighten it. (Make
sure if the plug washer is damaged. If so,
replace it with new one.)

Torque Value：3.5~4.5 kgf-m
Add new gear oil (100 c.c.) from the gear oil

filling hole and then install the gear oil filling
hole bolt after added oil. And then, tighten
the bolt.

Torque Value: 1.0~1.4 kgf-m
※Recommended to apply with SYM

HYPOID GEAR OIL (SAE 85W-140)

Start engine and run it for 2~3 minutes.
Turn off engine and check if oil leaking.

Filling bolt

Draining bolt

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SYM 4. FUEL SYSTEM

4-1

MECHANISM ILLUSTRATION.............4-1

PRECAUTIONS IN OPERATION.........4-2

TROUBLE DIAGNOSIS........................4-3

CARBURETOR REMOVAL..................4-4

VACUUM CHAMBER...........................4-4

AIR CUT-OFF VALVE ..........................4-6

AUTO BY-STARTER.......................... 4-7

FLOAT CHAMBER.............................4-8

INSTALLATION OF CARBURETOR..4-9

IDLE SPEED ADJUSTMENT..............4-9

FUEL TANK........................................4-10

AIR CLEANER....................................4-11

MECHANISM ILLUSTRATION

Carburetor

Fuel strainer

Fuel tank cap

Fuel unit

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4. FUEL SYSTEM SYM

4-2

PRECAUTIONS IN OPERATION

General Information

Warning

Cautions

Specification

Item Specification
Main jet 110#
Slow jet 35#
Idle speed 1700±100 rpm

Fuel quantity
adjustment screw

2 1/8±3/4 turns

Level in float chamber 3.0±1 mm
Jet needle DB4E6 add 1 unit 0.5mm washer
Throttle handle free play 2~6 mm

Torque value

Fuel valve tightening nut: 1.5~2.0 Kgf-m

Tool

Special service tools

Vacuum/air pressure pump

General service tools

Fuel level gauge

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.



Do not bend or twist throttle valve cable. Damaged cable will make unstable
driveability.

 When disassembling fuel system parts, pay attention to O-ring position, replace with

new one as re-assembly

 There is a drain screw in the float chamber for draining residual gasoline.
 Do not disassemble automatic by-starter and air cut-off valve arbitrarily.

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SYM 4. FUEL SYSTEM

4-3

TROUBLE DIAGNOSIS

Poor engine start

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

ignition system)

 Clogged air cleaner
 Malfunction of automatic by-starter

 Malfunction of throttle valve operation

Stall after started

 Malfunction of automatic by-starter
 Incorrect ignition timing
 Malfunction of carburetor
 Dirty engine oil
 Air existing in intake system

 Incorrect idle speed

Rough idle

 Malfunction of ignition system
 Incorrect idle speed
 Malfunction of carburetor

 Dirty fuel

Intermittently misfire as acceleration



Malfunction of ignition system

Late ignition timing

 Malfunction of ignition system

 Malfunction of carburetor

Power insufficiency and fuel consuming

 Fuel system clogged

 Malfunction of ignition system

Mixture too lean

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

 Air existing in intake system

Mixture too rich

 Clogged air injector
 Malfunction of float valve
 Fuel level too high in float chamber
 Malfunction of automatic by-starter

 Dirty air cleaner

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4. FUEL SYSTEM SYM

4-4

Carburetor Removal

Remove the luggage box.
Loosen the adjustment nut and fixing nut of
throttle valve cable, and release the cable
from carburetor.
Remove fuel pipe, vacuum hose.
Disconnect auto by-starter connectors.
Release the clamp strip of air cleaner.
Release the clamp strip of carburetor isolator.
Take the carburetor out.

VACUUM CHAMBER
Removal

Loosen drain screw, and drain out residual
fuel in float chamber.
Remove screws (2 screws) of vacuum
chamber cover and the cover.

Remove compress spring and vacuum
piston.

throttle valve cable

clamp strip of
isolator

vacuum
hose

Screws×2

Vacuum Chamber cove

r

Vacuum piston

compress
spring

vacuum hose

auto by-starte

r

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SYM 4. FUEL SYSTEM

4-5

Remove fuel needle seat, spring, and
injector needle.
Check if the vacuum piston for wear out,
crack or other damage.
Check if the diaphragm for damage or crack.

Cautions

Installation

Install injector needle, spring and fuel needle
seat to vacuum piston.

Cautions

Install vacuum piston to carburetor body.
Install compress spring.

Install vacuum chamber cover and tighten 2
screws.

Do not damage vacuum diaphragm.

 Note direction as installing the piston

set because wrong direction of the
piston cab not be installed.

 Align the indent of vacuum

diaphragm with the carburetor body.

fuel needle
seat

injector
needle

Piston spring

piston

fuel needle
spring

piston diaphragm lock
position

screws×2

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4. FUEL SYSTEM SYM

4-6

AIR CUT-OFF VALVE

Removal

Remove the vacuum hose clamp and then
the vacuum hose.

Remove the screws (screw x 2) of the air
cut-off valve and its cover.

Remove the spring and vacuum diaphragm.
Check if the vacuum diaphragm for
deterioration or crack.

Installation

Install the valve as reverse order of removal.

Cautions

Do not damage the vacuum diaphragm
or in opposite installation direction.

S

crews ×

2

vacuum diaphragm

screws

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SYM 4. FUEL SYSTEM

4-7

AUTO BY-STARTER

Inspection

Turn off engine and waiting for over 10
minutes for cooling.
Check resistance across the two terminals of
the auto by-starter

Resistance value: Max. 10Ω (Measured
after engine stopped for more than 10

minutes)

Replace the auto by-starter with a new one if
resistance value exceeds standard.
Remove the carburetor, allow it to cool off for
30 minutes.
Connect a hose to fuel richment circuit.
Pump compressed air to the circuit.
Replace the auto by-starter if the circuit
clogged.

Connect battery posts (12V) to starter’s
connectors. After 5 minutes, test the rich
circuit with compressed air. If air flow
through the circuit, then replace the starter.

Removal

Remove fixing plate screw, and then remove
the plate and auto by-starter from carburetor.

Valve inspection

Check if auto by-starter and valve needle for
damage or wear out.

Installation

Install auto by-starter to the carburetor body.
Install fixing plate to the upper groove of auto
by-starter, and install its flat surface to
carburetor. Install screw and tighten it.

Cautions

Align the round point of the starter with
the screw hole of air intake side.

valve needle

fixing plate

Screws × 2

fixing plate

automatic
by-starter

Screws
×2

round point

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4. FUEL SYSTEM SYM

4-8

FLOAT CHAMBER

Disassembly

Remove 4 mounting screws and then the
float chamber cover.
Remove the float pin and float valve.

Checking

Check float needle valve and valve seat for
drop difference damage, wear out, dirty or
clogged.

Cautions

Remove main jet, fuel needle jet holder, fuel
needle jet, slow jet, fuel amount adjustment
screw.

Cautions

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

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.

 Take care not to damage jets and adjust

screw.

 Before removing adjustment screw, turn

it all the way down and note the number
of turns.

 Do not turn adjustment screw forcefully

to avoid damaging valve seat face.

screws× 4

float

float pin

main jet

fuel needle jet

fuel needle holder

slow jet

float

float pin

float needle
valve

float pin

main jet

slow jet

fuel needle

j

et

fuel needle
holder

fuel amount

ad

j

ustment screw

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SYM 4. FUEL SYSTEM

4-9

Installation

Install main jet, fuel needle jet seat, fuel needle jet,
slow speed jet and fuel amount adjustment screw.

Cautions

Install the float valve, float, and float pin.

Checking Fuel Level

Cautions

Fuel level: 3.0±1mm

INSTALLATION OF CARBURETOR

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

 Throttle valve cable clearance adjustment

 Idle speed adjustment

IDLE SPEED ADJUSTMENT

Caution

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

Standard turns: 2 1/8±3/4 turns

Warm up engine, adjust throttle valve stopper
screw to standard RPM.

Idle speed rpm: 1700±100 rpm

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

CO standard value: 1.0~1.5 %

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

Set the adjustment screw in according to
n

umber o

f turns noted before it was removed.



Check again to ensure float valve, float for

proper installation.

 To ensure correct measurement, position

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

 Fuel amount adjust 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.

 Never screw in forcedly to avoid damaging

the screw seat.

 The main stand must be used to support the

motorcycle to perform the adjustments.

float mete

r

fuel amount
adjustment screw

Throttle valve cable
adjustment nut

throttle valve
stopper screw

air volume
adjustment screw

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4. FUEL SYSTEM SYM

4-10

FUEL TANK

Fuel unit removal

Open the seat.
Remove the luggage box. (6 bolts)
Remove the engine starter control switch
wire connector .
Disconnect fuel unit connector.
Remove fuel unit.

Cautions

Fuel unit inspection. (Refer to chapter 16 ­electrical equipment).

Fuel unit installation
Install the gauge in the reverse order of
removal.

Cautions

FUEL TANK REMOVAL

Open the seat.
Remove the luggage box assembly (6 bolts).
Disconnect the engine start control switch
connector.
Disconnect the fuel unit connector.

Remove the fuel pipe, fuel filter.
Remove the fuel tank (2 bolts).

Fuel Tank Installation

Install the tank in the reverse order of
removal.



Do not bend the float arm of fuel unit.

 Do not fill out too much gasoline to

fuel tank.

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

fuel unit

gasket

Fuel unit connecto

r

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SYM 4. FUEL SYSTEM

4-11

AIR CLEANER

Removal

Remove the seat .
Remove the luggage box assembly (6 bolts).
Disconnect the engine start control switch
connector.
Loosen the clamp strip of air cleaner.
Remove evaporative return hose.
Remove the air cleaner body bolts (2 bolts).
Remove the air cleaner.

Installation

Install the air cleaner in the reverse order of
removal.

Air Cleaner Element Cleaning
Remove the air cleaner cover (6 screws).

Remove the air cleaner element (2 screws).
With compressed air to clean dirty around
the element. Replace it if it is too dirty to
clean.

Cautions

The air cleaner element is made of
paper so do not soap it into water or
wash it with water.

air filter strap

screws×2

Air cleaner element

bolts×2

screws×6

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SYM 5. REMOVAL OF ENGINE

5-1

MECHANISM DIAGRAM......................5-1

OPERATIONAL PRECAUTIONS .........5-2

ENGINE REMOVAL .............................5-3

REMOVAL OF ENGINE SUSPENSION BUSHING .5-6

ENGINE SUSPENSION FRAME..........5-7

INSTALLATION OF ENGINE............... 5-8

MECHANISM DIAGRAM

3.5~4.5kgf-m

2.4~3.0kgf-m

4.5~5.5kgf-m

4.5~5.5 kgf-m

4.5~5.5kgf-m

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5. REMOVAL OF ENGINE SYM

5-2

OPERATIONAL PRECAUTIONS

General Information

 Engine must be supported by a bracket or adjustable tool in height.
 The following parts can be serviced with the engine installed on the frame.

1. Carburetor

2. Driving disk, driving belt, clutch, and transporting disk

3. Final reduction gear mechanism

Specification

Specification

Disassemble 850 c.c.

Engine Oil Capacity

Replacement 750 c.c.

Disassemble 110 c.c.

Gear Oil Capacity

Replacement 100 c.c.

Torque Values

Engine suspension bolt (frame side) 4.5~5.5kgf-m
Engine suspension nut (engine side) 4.5~5.5kgf-m
Bolt of rear shock absorber upper connection 3.5~4.5kgf-m
Bolt of rear shock absorber lower connection 2.4~3.0kgf-m

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SYM 5. REMOVAL OF ENGINE

5-3

ENGINE REMOVAL

Open the seat.
Remove the luggage box assembly (4
bolts ).
Remove the body cover .
Remove the power connector of auto by­start.
Remove the generator wire and pulse
generator connector.

Remove the starter motor wire on the Starter
magnetic switch.

Remove the spark plug.

Spark plug

Starter magnetic switch

Auto by-start

connector

G

enerato

r

connector

pulse generator

connector

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5. REMOVAL OF ENGINE SYM

5-4

Remove the fuel pipe, vacuum hose, and
throttle valve cable from the carburetor.
Loose the strap screw of the air cleaner
guide, and then the air cleaner guide.

Remove the exhaust muffler (Bolts ×
2, Nuts × 2).

Remove the rear wheel (Nut × 1).

Remove the air cleaner connection bolts (2
bolts).

Nut ×1

Bolts×2

bolts×2

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SYM 5. REMOVAL OF ENGINE

5-5

Remove the rear brake cable nut.
Remove the rear brake cable.
Remove the rear shock absorber lower bolt.

Loose the strap screw of engine left guide,
and then remove the engine left guide.

Remove the engine suspension nut and bolt
(engine side), and then remove the engine.

Caution

Check if the engine suspension, rear shock
absorber bushing, and cushion rubber for
damage. Replace them with new ones if so.

Strap screw of guide

 With a bracket to support the engine

to prevent from it damage by falling
down as removing the engine.

Engine suspension bolt/nut

Brake cable nut

Rear shock
absorber bolt

Bushing

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5. REMOVAL OF ENGINE SYM

5-6

REMOVAL OF ENGINE
SUSPENSION BUSHING

If engine suspension frame and the cushion
rubber of rear shock absorber bushing
damaged. Then, with the bushing remover /
presser, Φ28mm &Φ20mm, to press the
bushing out, and replace it with new one.

Engine suspension bushing: Φ28mm
Rear shock absorber bushing: Φ20mm

Pressing out

Place the detent section of the bushing
remover toward the bushing, and drive both
the pressing ring and bolt in to press the
bushing out.

Pressing In
Place the flat section of the remover toward
the bushing, and then drive the bushing,
pressing ring, and bolt in to install the
bushing.

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SYM 5. REMOVAL OF ENGINE

5-7

ENGINE SUSPENSION FRAME

Removal

Remove the right side bolt of engine
suspension frame.

Remove the left side bolt of engine
suspension frame.

Check if the engine suspension frame
bushing and cushion rubber for damage. If
so, replace with new ones.

Installation

Tighten the bolts and nuts of engine
suspension frame.

Engine suspension frame nut:
Torque Value: 4.5~5.5 kgf-m

Bolt of engine suspension
frame (left side)

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5. REMOVAL OF ENGINE SYM

5-8

INSTALLATION OF ENGINE

Check if the bushings of engine suspension
frame and shock absorber for damaged. If so,
replace with new ones.
Install the engine according to the reversing
order of removal.

Caution

Engine suspension nut:
Torque Value: 4.5~5.5kgf-m

Rear shock absorber bolt:
Torque Value: Top: 3.5~4.5kgf-m

lower: 2.4~3.0kgf-m

Rear wheel axle nut:
Torque Value: 11.0~13.0kgf-m

 Notice both feet and hands safety for

squeezing as engine installation.

 Do not bent or squeeze each wires or

hose.

 Route all cables and wires in

accordance with the routine layout.

Engine suspension nut×1

Rear shock
absorber lower bolt

Brake cable nut

Rear wheel axle nut×1

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SYM 6. CYLINDER HEAD/VALVE

6-1

MECHANISM DIAGRAM....................6-1

PRECAUTIONS IN OPERATION.......6-2

TROUBLE SHOOTING.......................6-3

CAMSHAFT REMOVAL .....................6-4

CYLINDER HEAD REMOVAL............6-6

CYLINDER HEAD DISASSEMBLY ....6-7

CYLINDER HEAD INSPECTION..........6-8

VALVE SEAT INSPECTION AND SERVICE

6-10

CYLINDER HEAD REASSEMBLY.......6-12

CYLINDER HEAD INSTALLATION......6-13

CAMSHAFT INSTALLATION ...............6-13

VALVE CLEARANCE ADJUSTMENT..6-14

MECHANISM DIAGRAM

1.0~1.4 kgf-m

1.0~1.5 kgf-m

1.0~1.4 kgf-m

0.8~1.2 kgf-m

1.8~2.2 kgf-m

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6. CYLINDER HEAD/VALVE SYM

6-2

PRECAUTIONS IN OPERATION

General Information

 This chapter is contained maintenance and service for cylinder head, valve, and camshaft

as well as valve rocker arm.

 Cylinder head service cannot be carried out when engine is in frame.

Specification unit: mm

Item Standard Limit

Compression pressure 13 kgf/cm² -

Intake 25.965 25.290

Camshaft

Height of cam lobe

Exhaust 25.81 25.120

ID of valve rocker arm 10.00 10.000~10.015

Rocker

arm

OD of valve rocker arm shaft 10.00 9.985~10.00

Intake 5.00 4.975~4.99

OD of valve stem

Exhaust 5.00 4.97~4.98

OD of Guide 5.00 5.030

Intake 0.020~0.045 0.080

Clearance between

valve stem and guide

Exhaust 0.030~0.057 0.100

Outer 32.56 32.26

Free length of valve

spring

Inner 35.25 34.75~35.75

Valve

Valve seat width 1.000 1.600

Connection Flatness of cylinder head

- 0.050

Torque Value

Cylinder head cover bolts 0.8~1.2kgf-m
Holder nuts 1.0~1.5kgf-m
Cylinder head bolts 0.8~1.2kgf-m
Valve adjustment fixing nuts 1.0~1.5kgf-m
Camshaft chain auto-adjuster bolts 0.8~1.2kgf-m
Timing gear cover bolts 0.7~1.1kgf-m (apply with oil on bolt thread & seat)
Spark plug 1.0~1.4kgf-m

TOOLS
Special service tools

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

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SYM 6. CYLINDER HEAD/VALVE

6-3

TROUBLE SHOOTING

Engine performance will be effected by troubles on engine top end. The troubles usually can
be determinate or by performing cylinder compression test and judging the abnormal noise
generated.

Rough Idle

Low compression pressure.

Low compression pressure

1. Valve

 Improper valve adjustment.
 Burnt or bended valve.
 Improper valve timing.
 Valve spring damaged.
 Valve carbon.
 Poor sealing on valve seat.
 Improper spark plug installation.

2. Cylinder head

 Cylinder head gasket leaking or damage.
 Tilt or crack cylinder surface.

3. Piston

 Piston ring worn out.

High compression pressure

 Too much carbon deposit on combustion chamber or piston head.

Noise

 Improper valve clearance adjustment
 Burnt valve or damaged valve spring
 Camshaft wear out or damage
 Cam chain wear out or looseness
 Auto-adjuster wear out or damage of cam chain
 Camshaft sprocket wear out
 Rocker arm or rocker arm shaft wear out

White smoke

 Valve guide or valve stem wear out
 Valve stem seal wear out

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6. CYLINDER HEAD/VALVE SYM

6-4

CAMSHAFT REMOVAL

Remove the shroud of the engine.
Remove the crankcase blow-by system hose
from the cylinder head.
Remove the cylinder head bolts and then
remove the cylinder head (4 bolts).

Loosen the screw of camshaft chain adjuster
and remove O-ring.
With a flat screwdriver to tighten the screw of
camshaft chain adjuster in a clockwise
motion for release adjuster.

Turn the flywheel in counter clockwise
motion with T type wrench until the “T” mark
on flywheel aligned with the mark on the
crankcase so that the hole on the camshaft
sprocket is forward up and piston is at TDC
position.

Remove camshaft holder nut and washer.

Caution

Loosen the nuts diagonally by 2-3
sequences.

TDC mark

Hole

4 nuts

screw

camshaft chain adjuster

Blow-by hose

4 bolts

A

.I

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SYM 6. CYLINDER HEAD/VALVE

6-5

Remove the camshaft holder and rocker arm
set.
Remove the camshaft chain from the
camshaft sprocket.
Remove the camshaft.

Camshaft Inspection

Inspect cam lobe height for damaged.

Service Limit
IN: Replacement when less than 25.29 mm
EX: Replacement when less than 25.12 mm

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

Disassembly Of Camshaft Holder

With a 5 mm bolt to screw in the cam rocker
arm shaft so that take it out.
Remove cam rocker arm.

Inspection Of Camshaft Holder

Check if the camshaft holder, cam rocker
arm and rock arm shaft for wearing out or
damage.

Caution

Measure the cam rocker arm I.D. of the
camshaft holder.

Service Limit: Replace when it is above

12.10 mm



Further check is necessary if any wea

r

is found on the moveable surface of
cam rocker arm.

 Check if the camshaft bearing mounting

surface for wear or damage.

Camshaft
bearin

g

5mm bolt

rocker arm
shaft

rocker arm

rocker arm
shaft

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6. CYLINDER HEAD/VALVE SYM

6-6

Measure the valve rocker arm I.D.

Service Limit: Replace when it is above

10.100 mm

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

Service Limit: Replace when it is above

9.910 mm

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

Service Limit: Replace when it is above

0.10 mm

CYLINDER HEAD REMOVAL

Remove double seat, luggage box and front
center cover.
Remove the engine (refer to Chapter 5).
Remove the cooling fan cover.
Remove the engine shroud (4 bolts).

Remove the camshaft (refer to page 6-4).

Blow-by hose

4 bolts

A

.I

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SYM 6. CYLINDER HEAD/VALVE

6-7

Remove the 2 cylinder head mounting bolts
from cylinder head left side cover.
Remove cylinder head gasket and 2 dowel
pins.
Remove chain plate.
Clean up residues from the matching
surfaces of cylinder and cylinder head.

Caution

CYLINDER HEAD DISASSEMBLY

Use a valve compressor to press the valve
spring.

After removed valve cotters, release the
compressor and then take out spring retainer,
valve spring and valves.

Caution

Special Service Tool: Valve spring compressor.

Remove valve stem guide seal.
Clean carbon deposits in combustion chamber.
Clean residues and foreign materials on
cylinder head matching surface.

Caution



Do not damage the matching surfaces of
cylinder and cylinder head.

 Avoid residues of gasket or foreign

materials falling into crankcase as
cleaning.

In order to avoid to loosing spring
tension, do not compress the spring too
much. Its length is based on the
installation of latch.

Do not damage the matching surface of
cylinder head.

dowel pins

Cylinder head gasket

Chain plate

valve cotters

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6. CYLINDER HEAD/VALVE SYM

6-8

CYLINDER HEAD INSPECTION

Check if spark plug and valve holes are crack.
Measure cylinder head flat with a
straightedge and flat feeler gauge.

Service limit: 0.5mm

Valve spring free length

Measure the free length of intake and
exhaust valve springs.

Standard
Outer : 35.250 mm
Inner : 32.410 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→ 4.900mm
EX→ 4.900mm

Valve guide

Caution

Special Service Tool: 5.0mm valve guide
reamer
Measure and record each valve guide inner
diameters.
Service limit: 5.030mm
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→ 0.08mm
EX→ 0.10mm

Before measuring the valve guide, clean
carbon de

p

osits with reamer.

5.0mm valve guide reamer

The narrow pitch of the spring shall face to the
combustion chamber.

http://www.motorcycle.in.th

SYM 6. CYLINDER HEAD/VALVE

6-9

Caution

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

Caution

Valve guide replacement

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

Caution

Hold the cylinder head, and then press out old

valve guide from combustion chamber side.

Tool: Valve guide driver 5 mm

Caution

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

Tool: Valve guide driver 5 mm

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

Caution

Correct valve seat, and clean up all metal
residues from cylinder head.

Special tool: Valve guide reamer 5 mm

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.

It must correct valve seat when replacing
valve guide.

 Do not let torch heat cylinder head

directly. Otherwise, the cylinder head
may be deformed as heating it.

 Wear on a pair of glove to protect your

hands when operating.



Check if new valve guide is deformation
after pressed it in.

 When pressing in the new valve guide,

cylinder head still must be kept in
100~150 ℃.



Using cutting oil when correcting valve
guide with a reamer.

 Turn the reamer in same direction when

it be inserted or rotated.

V

alve guide drive

r

5.0mm

V

alve guide drive

r

5.0mm

13 mm

(0.15in)

Valve guide reamer 5.0mm

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6. CYLINDER HEAD/VALVE SYM

6-10

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

Remove the valve and check its contact
face.

Caution

Valve seat inspection

If the valve seat is too width, narrow or rough,
correct 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 grinded with
valve seat chamfer cutter.
Use 45° valve seat chamfer cutter to cut any
rough or uneven surface from valve seat.

Caution

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

 Do not let emery enter into between

valve stem and valve guide.

 Clean up the emery after corrected,

and apply with red paint onto contact
faces of valve and valve seat.

Replace the valve with new one if valve
seat is roughness, wear out, or
incomplete contacted with valve seat.
If the valve and the valve seat still can
not be matched sealing after grinded,
replace it with new one.

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

valve seat

width

45°

Roughness

32°

Old valve seat width

V

alve seat

width

http://www.motorcycle.in.th

SYM 6. CYLINDER HEAD/VALVE

6-11

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

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

Caution

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.

Caution

If the contact surface too high, grind the
valve seat with 32° cutter.
Then, grind the valve seat with 45° cutter to
specified width.

If the contact surface too low, grind the valve
seat with 60° cutter.
Then, grind the valve seat with 45° cutter to
specified width.

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

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

Old valve seat width

60°

45°

1.0mm

Contact surface too high

32°

Old valve seat
width

Contact surface
too low

60°

Old valve seat
width

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6. CYLINDER HEAD/VALVE SYM

6-12

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

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

Use valve spring compressor to press valve
spring.
Install valve split locks and release the valve
compressor.

Caution

Special tool: valve spring compressor

Tap valve stem to make valve retainer and
valve stem sealing properly.

Caution

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

In order to avoid to loosing spring
tension, do not compress the spring too
much. Its length is based on the
installation of latch.

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

Valve

V

alve stem

oil seal

Valve spring

V

alve spring

retainer

Valve cotters

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SYM 6. CYLINDER HEAD/VALVE

6-13

CYLINDER HEAD INSTALLATION

Install the lock pins and new cylinder head
gasket onto the cylinder head.
Install the camshaft chain plate.

Install the cylinder head.

CAMSHAFT INSTALLATION

Assemble the camshaft holder.
Install the exhaust valve rocker arm set onto
the camshaft holder showing “EX” mark.
Install intake valve rocker arm and rocker
arm shaft.

Caution

With T type wrench to turn crankshaft in a
clockwise motion so that the “T” mark on the
flywheel aligns with the mark on crankcase.
(piston is at TDC position)
Place the TDC marks of the cam sprocket at
same level of the top-end of cylinder head.
The other single hole of the cam sprocket is
in upward. Then, install the cam chain onto
the cam sprocket.

The tangent of rocker shaft of intake
valve should match with the bolt hole of
camshaft mounting seat.

Lock pins

Cylinder head gasket

Chain plate

5mm blot

Rocker
arm shaft

Rocker arm

Camshaft

Cam chain

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6. CYLINDER HEAD/VALVE SYM

6-14

Install the lock pins.
Install the camshaft holder, gasket and nut
onto the cylinder head.
Tighten the cylinder head nuts. (4 nuts)
At first, tighten the 4 nuts on the cylinder top
and then tighten the 2 bolts on the left side of
cylinder head.

Torque value: 1.8~2.2 kgf-m

Install the spark plug and tighten it.

Torque value: 1.0~1.4 kgf-m

Caution

VALVE CLEARANCE ADJUSTMENT

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:

0.12±0.02/ 0.12±0.02 mm

With flat screwdriver, turn the cam sprocket
adjuster in counter-clockwise motion so that
the adjuster is pushed out to contact the cam
chain plate tightly. Apply with oil onto a new
O-ring and then install it onto the adjuster
hole. Tighten the bolt cap of the adjuster
adjustment hole.

Caution

Replace the O-ring of the cylinder head with
new one. Install the cylinder head.

Tighten the cylinder head lock bolts.
Connect the blow-by hose onto the cylinder
head.
Tighten the 2nd air injection (AI) nut.
Install the engine onto the engine frame.
(Refer to Chapter 5)



A

pply with oil onto the thread of cylinder
head bolts and tighten the bolts in
diagonally for 2-3 sequences.

 Do not over tightening the bolts to avoid

the cylinder head deformation, noise
created or leaking so that effects
motorcycle’s performance.

The O-ring must be installed into glove.

pin

holder

Especial tool

Blow-by hose

4 bolts

A

.I

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SYM 7. CYLINDER/PISTON

7-1

MECHANISM DIAGRAM....................7-1

PRECAUTIONS IN OPERATION.......7-2

TROUBLE DIAGNOSIS......................7-2

CYLINDER REMOVAL.......................7-3

PISTON REMOVAL............................7-5

PISTON RING INSTALLATION..........7-7

PISTON INSTALLATION....................7-8

CYLINDER INSTALLATION.............. 7-8

MECHANISM DIAGRAM

0.8~1.2kgf-m

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7. CYLINDER/PISTON SYM

7-2

PRECAUTIONS IN OPERATION

General Information

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

Specification unit: mm

Item Standard Limit
ID 58.50 58.2~58.5
Bend/wrap age

－

0.050

Roundness 0.005 0.050

Cylinder

Cylindrical 0.005 0.050

Top ring 0.025~0.060 0.090

Clearance between
piston rings

2nd ring 0.015~0.050 0.090
Top ring 0.200~0.400 0.500
2nd ring 0.250~0.400 0.650

Ring-end gap

Oil ring

0.200~0.700

－

OD of piston 52.370~52.390 52.300
Piston OD measurement position

Lower-end up 7mm

of piston skirt

－

Clearance between piston and
cylinder

0.010~0.040 0.100

Piston/
Piston ring

ID of piston pin hole 15.002~15.008 15.040

OD of piston pin 14.994~15.000 14.980
Clearance between piston and piston pin 0.002~0.014 0.060
ID of connecting rod small-end 15.005~15.020 15.060

TROUBLE DIAGNOSIS
Low Or Unstable Compression Pressure

Cylinder or piston ring worn out.
Compress pressure to high.
Too much carbon deposited in combustion
chamber and piston.

Knock or Noise

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

Smoking in Exhaust Pipe

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

Engine Overheat

Carbon deposits on cylinder head top side.

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SYM 7. CYLINDER/PISTON

7-3

CYLINDER REMOVAL

Remove cylinder head. (refer to chapter 6)
Remove 2 bolts and then take out the cam
chain auto-adjuster.

Remove cam chain plate.
Remove cylinder.

Remove cylinder gasket and lock pins

Clean the residues attached onto the
matching surfaces of cylinder and
crankcase.

Cylinder

2 bolts

C

am chain

auto-adjuster

C

am chain

guide

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7. CYLINDER/PISTON SYM

7-4

Cover the holes of crankcase and cam chain
with a piece of cleaning cloth.
Clean up all residues or foreign materials
from the two matching surfaces of cylinder
and crankcase.

Caution

INSPECTION

Check if the inner diameter of cylinder is
worn out or damaged.
In the 3 positions (top, center and bottom)
of cylinder, measure the X and Y direction
values respective in the cylinder.
Service limit: 58.00mm
Calculate both the real roundness (the
difference between X and Y motion values)
and the cylindrical roundness (the
difference in the top, center or bottom
positions of X or Y motion values.). Then,
determinate by the max. value.

Service limit
Real roundness: correct or replace as

over 0.05 mm

Cylindrical roundness: correct or replace

as over 0.05 mm

Check Cylinder flat.

Service limit: correct or replace as over

0.05 mm

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

Top
Center

Bottom

Exhaust side

I

ntake side

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SYM 7. CYLINDER/PISTON

7-5

PISTON REMOVAL

Plug crankcase opening with a cleaning cloth
to prevent from piston pin snap ring or other
parts falling into crankcase when
disassembling.
Hold another snap ring with pliers.
Push out the piston pin from the side that not
removed the snap ring.

Remove piston rings.

Caution

Disassemble the piston rings.
Check if the piston rings are damaged or its
grooves are worn.
Cleaning the carbon in piston ring grooves.

Install the piston rings and then measure
clearance between piston ring and its
grooves.

Service Limit: Top ring: replace if over

0.09mm

2nd ring: replace if over

0.09mm

Take out the piston rings and place them
respective into cylinder below 20mm of
cylinder top. Measure each piston ring
gaps.

Caution

Service Limit: Top ring: replace if over

0.50mm

2nd ring: replace if over

0.650mm

Pay attention to remove piston rings
because they are fragile.

Push the piston rings into cylinder with
piston top-end in parallel motion.

Piston ring

Push in

Feeler gauge

Piston

piston ring

Feeler gauge

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7. CYLINDER/PISTON SYM

7-6

Measure the outer diameter of piston pin.

Service Limit: 14.980mm

Measure the inner diameter of connecting
rod small end.

Service Limit: 15.06mm

Measure the inner diameter of piston pin
hole.

Service Limit: 15.04mm

Calculate clearance between piston pin and
its hole.

Service Limit: 0.02mm

Measure piston outer diameter.

Caution

Service limit: 52.30mm

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

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

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SYM 7. CYLINDER/PISTON

7-7

PISTON RING INSTALLATION

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

Caution

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

Top groove

2nd groove

Oil groove

Top ring

2nd ring

Oil ring

Spacer

Side ring

Side ring

Over 20 mm

120°

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7. CYLINDER/PISTON SYM

7-8

PISTON INSTALLATION

Install piston and piston pin, and place the IN
mark on the piston top side forward to intake
valve.
Install new piston pin snap ring.

Caution

CYLINDER INSTALLATION

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

Install 2 lock pins and new gasket.

Coat 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

Install the cam chain plate, the cylinder
gasket and lock pins.
Install cylinder head. (refer to Chapter 6)
Install the cam chain auto-adjuster. (2 bolts)

 Do not let the opening of piston pin snap

ring align with the opening piston ring.

 Place a piece of cleaning cloth between

piston skirt section and crankcase in
order to prevent snap ring from falling
into crankcase as operation.

Do not push piston into cylinder forcefully
because this will cause the piston and the
piston rings to be damaged.

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

Piston pin

IN mark

Piston

2 bolts

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-1

MECHANISM DIAGRAM....................8-1

MAINTENANCE DESCRIPTION........8-2

TROUBLE DIAGNOSIS......................8-2

LEFT CRANKCASE COVER..............8-3

KICK STARTER ARM ........................8-3

DRIVING BELT...................................8-4

SLIDING PULLEY ..............................8-6

CLUTCH/DRIVEN PULLEY............... 8-9

MECHANISM DIAGRAM

5.0~6.0kgf-m

5.0~6.0kgf-m

0.8~1.2kgf-m

5.0~6.0kgf-m

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-2

MAINTENANCE DESCRIPTION

PRECAUTIONS IN OPERATION
GENERAL INFORMATION

• Driving pulley, clutch, and driven pulley can be serviced on the motorcycle.

• Driving belt and driving pulley surface must be free of grease.

Specification Unit: mm

Item Standard value Limit

Driving belt width

19.000

17.500

ID of sliding pulley bushing

23.989~24.052

24.060

OD of sliding pulley hub

23.960~23.974 23.940

OD of roller

17.920~18.080 17.400

ID of clutch outer

125.000~125.200 125.500

Thickness of clutch lining

2.000 1.500

Free length of driving pulley
spring

168.900 163.700

OD of driving pulley

33.965~33.985 33.940

ID of sliding pulley

34.000~34.025 34.060

ID: Inner Diameter
OD: Outer diameter

Torque value

Sliding pulley nut: 5.0~6.0kgf-m
Clutch outer nut: 5.0~6.0kgf-m
Driving pulley nut: 5.0~6.0kgf-m
Left crankcase cover bolts: 0.8~1.2kgf-m

Special Service Tools

Clutch spring compressor
Bearing puller (inner type)
Clutch mounting nut wrench
Universal fixture

TROUBLE DIAGNOSIS

Engine can be started but motorcycle
can not be moved

1. Worn driving Belt

2. Worn tilt plate

3. Worn or damaged clutch lining

4. Broken driven pulley

Shudder or misfire when driving

1. Broken clutch lining

2. Worn clutch lining

Insufficient horsepower or poor high
speed performance

1. Worn driving belt

2. Insufficient spring capacity of driven
pulley

3. Worn roller

4. Driven pulley operation un-smoothly

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-3

LEFT CRANKCASE COVER

Left crankcase cover removal

Remove air cleaner. (2 bolts)
Remove kick starter arm. (1 bolt)
Loosen vent strap on the front-left side of
cover, and then remove the vent.
Remove engine left-side cover (8 bolts).

KICK STARTER ARM

Disassembly

Remove the return spring plate (1 bolt), and
remove return spring, starter shaft.
Remove driving gear, friction spring and
washer.

Inspection

Check if starter shaft, driving gear, socket
and bearing hole for wear or damage.
Replace it with new one if necessary.
Check the return spring and friction spring for
spring force or damaged. Replace it with
one if poor parts found.

Reassembly

Apply with some specified grease on the
gear, socket, shaft.
Install the friction spring of driving gear onto
convex part of the case.
Install socket, return spring and starter shaft
as diagram shown.
Install kick starter arm temporary.
Rotate the lever and then align driving gear
with width-tooth on the starter shaft.
Install thrust washer and socket onto starter
shaft.

Installation of the left crankcase
cover

Install the left crankcase cover. (8 bolts)
Install front vent tube of left cover and tighten
the strap.
Install kick starter arm. (1 bolt)
Tighten the air cleaner. (2 bolts)
Install the air cleaner. (6 bolts)

Starter shaft

Return spring

Friction spring

Driving gear

driving gear

starter shaft gear

air cleaner lock nut

kick starter arm

kick starter arm

Kick starter arm

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-4

DRIVING BELT

Removal

Remove left crankcase cover.
Hold the driving pulley with a universal fixture,
and then remove the nut and driving pulley.

Hold driving pulley with universal fixture, and
remove nut and clutch outer.

Caution

Push the driving belt into belt groove as
diagram shown so that the belt can be
loosened, and then remove.
Driving belt and clutch at same time.

Inspection

Check the driving belt for crack or wear.
Replace it if necessary.
Measure the width of driving belt as diagram
shown. Replace the driving belt if it exceed
maintenance limited specification.

Service Limit: 19.0mm

Caution

Using special service tools for tightening or
loosening the nut. Fixed rear wheel or
rear brake only will damage reduction gear
system.

 Using the genuine parts for

replacement.

 The surfaces of driving belt or pulley

must be free of grease.

 Clean up all grease or dirt before

installation.

Nut

Universal fixe

r

Width

Tooth

Driving belt

Universal fixer

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-5

Installation

Pull out the driving pulley and then insert the
driving pulley.

Caution

Install the clutch set with driving belt onto the
driving shaft.
Install the sliding pulley on the other end of
belt.
Install clutch outer.

Install the clutch with universal fixture, and
then tighten nut to specified torque value.

Torque value: 5.0~6.0 kgf-m

Caution

Pull out driving pulley and then insert the
driving belt into the driving pulley so that
the driving belt set can be installed onto
sliding pulley more easily.

Sliding
driven
pulley

Clutch outer

Nut

Universal fixer

When install the driving belt, if there is a
arrow mark, then the arrow mark must
point to rotation motion. If not, the letters
on the belt must be forwarded to
assembly direction.

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-6

SLIDING PULLEY

REMOVAL

Remove left crankcase cover.
Hold driving pulley with universal fixture, and
then remove driving pulley nut.
Remove driving pulley.

Remove the driving belt from the pulley.
Remove sliding pulley set and driving pulley
hub from crankshaft.

Remove tilt plate.

Remove weight rollers from sliding pulley.

Crankshaft

Driving pulley hub

Sliding pulley

Tilt plate

Sliding pulley

Roller

Universal fixture

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-7

Inspection

The operation of sliding pulley is means of
the weight roller to pressing on it with
centrifuge force. And then the speed is
changed by the title plate rotation. Thus, if
weight rollers are wear out or damage, the
centrifuge force will be effected.
Check if rollers are wear out or damage.
Replace it if necessary.
Measure each rollers’ outer diameter.
Replace it if exceed the service limit.

Service limit: 19.50 mm

Check the pulley hub if damaged or wear out.
Replace it if necessary.
Measure the pulley hub’s outer diameter.
Replace it if exceed the service limit.

Service limit: 23.94 mm

Measure the pulley hub’s inner diameter.
Replace it if exceed the service limit.

Service limit: 24.06 mm

Assembly/Installation

Install the weight rollers.

Install the title plate guide boot onto the title
plate.
Install the title plate.

Weight roller

Sliding pulley

Pulley hub

Guide boot

Tilt plate

Weight roller

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-8

Apply with grease 4~5 g to inside of driving
shaft hole, and install driving pulley hub.

Caution

Install siding pulley assembly onto crankshaft.

DRIVING PULLEY INSTALLATION

Press driving belt into pulley groove, and
then press down the up & down sides of the
driving belt to separate it away from the
driving pulley hub.

Caution

Install driving pulley, washer and nut.

Caution

Hold driving pulley with universal fixture.
Tighten nut to specified torque.

Torque value: 5.0~6.0 kgf-m

Install left crankcase cover.

The pulley surface has to be free of
grease. Clean it with cleaning solvent.

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

To press down the up & down sides of
the driving belt can avoid to pressing and
damaging the belt when installing the
driving pulley, and also can make sure
that the driving pulley can be tighten.

Pulley surface

Crankshaft

Pulley hub

Sliding pulley

Driving belt

Press down

Universal fixture

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-9

CLUTCH/DRIVEN PULLEY

DISASSEMBLY

Remove driving belt and clutch/driven pulley.
Install clutch spring compressor onto the
pulley assembly, and operate the
compressor to let nut be installed more
easily.

Caution

Hold the clutch spring compressor onto
bench vise, and then remove mounting nut
with special nut wrench.
Release the clutch spring compressor and
remove clutch and spring from driven pulley.
Remove socket from driven pulley.

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

INSPECTION

Clutch outer

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

Service limit: 125.5 mm

Do not press the compressor too much.

Clutch outer

Inner

diameter

O-ring

Guide pin

Guide pin
roller

Guide pin

Oil seal

Sliding pulley

Socket

Clutch spring compressor

Special nut wrench

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-10

Clutch lining

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

Service limit: 2.0mm

Driven pulley spring

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

Service limit: 163.7mm

Driven pulley

Check following items;

• If both surfaces are damage or wear.

• If guide pin groove is damage or wear.

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

Service limit: Outer diameter 33.94mm
Inner diameter 34.06mm

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.

Free length

Guide pin
groove

Sliding disc

Driven pulley

Clutch

Clutch lining

Needle bearing

Outer ball bearing

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-11

Clutch Block Replacement

Remove snap and washer, and the remove
clutch block and spring from driving plate.
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.

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

Caution

Install the spring snap into groove with pliers.

 Grease or lubricant will damage the

clutch block and effect the block’s
connection capacity.

Shock absorption rubber

Clutch block

Spring

Spring

Driving plate

Snap ring

Clutch block

Shock absorption rubber

Setting pin

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8. V-BELT DRIVING SYSTEM/KICK STARTER ARM SYM

8-12

Install snap ring and mounting plate onto
setting pin.

REPLACEMENT OF DRIVEN PULLEY
BEARING

Remove inner bearing.

Caution

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 grease.
Recommended to use the KING MATE G-3.
Install the snap ring and hold the bearing.

Install a new inner bearing.

Caution

Align oil seal lip with bearing, and then install
the new oil seal (if necessary).

 Its sealing end should be forwarded to

outside as bearing installation.

 Install needle bearing with hydraulic

presser. Install ball bearing by means
of hydraulic presser.

 If the inner bearing equipped with oil

seal on one side in the driven pulley,
then remove the oil seal firstly.

 If the pulley equipped with ball bearing,

it has to remove snap ring and then the
bearing.

Snap ring

Inner bearing

Sealing end

Oil seal

Inner needle
bearing

Outer bearing

Snap ring

Snap ring

Outer bearing

Sealing end

Specified grease

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SYM 8. V-BELT DRIVING SYSTEM/KICK STARTER ARM

8-13

INSTALLATION OF CLUTCH/DRIVEN
PULLEY ASSEMBLY

Install new oil seal and O-ring onto sliding pulley. Apply with specified grease to lubricate
the inside of sliding pulley.

Install sliding pulley onto driven pulley.
Install guide pin and guide pin roller.

Install oil socket.

Install driving belt, spring and clutch into
clutch spring compressor, and press down
the assembly by turning manual lever until
mounting nut that can be installed.
Hold the compressor by bench vise and
tighten the mounting nut to specified torque
with special nut wrench.
Remove the clutch spring compressor.

Torque value: 5.0~6.0 kg-m

Install clutch/driven pulley and driving belt
onto driving shaft.

Oil seal

O-ring

Specified
grease

Oil socket

O-ring

Guide pin

Guide pin
roller

Guide pin

Oil seal

Sliding pulley

Clutch spring compressor

Special nut wrench

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SYM 9. FINAL DRIVING MECHANISM

9-1

MECHANISM DIAGRAM....................9-1

OPERATIONAL PRECAUTIONS .......9-2

TROUBLE DIAGNOSIS......................9-2

DISASSEMBLY OF FINAL DRIVING MECHANISM .........9-3

INSPECTION OF FINAL DRIVING MECHANISM..9-3

BEARING REPLACEMENT................9-4

RE-ASSEMBLY OF FINAL DRIVING MECHANISM.........9-6

MECHANISM DIAGRAM

driving gear

countershaft gear

final driving gear

final driving shaft

countershaft

1.8~2.2 kgf-m

1.0~1.4 kgf-m

3.5~4.5 kgf-m

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