This service manual contains the technical data of each component inspection and
repair for the SANYANG HD 125 / 200 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, HD 125 / 200, are different from that
of the photos, pictures shown in this manual, the actual vehicle shall prevail.
Specifications are subject to change without notice.
Service Department
SANYANG INDUSTRY CO., LTD.
Homepage
Contents
HOW TO USE THIS MANUAL
This service manual describes basic information of different system parts and
system inspection & service for SANYANG HD 125/200 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 information and special tools
manual.
The third to the 11th chapters cover engine and driving systems.
The 12th chapter is cooling system.
The 13th to the 16th chapter is contained the parts set of assembly frame body.
The 17th chapter is electrical equipment.
The 18th chapter is wiring diagram.
Please see index of content for quick having the special parts and system
information.
There are 4 buttons, “Forward”, “Contents”, “How to use this manual” and
“Mechanism Illustrations” on the CD-R version, and can be access to these items
by click the mouse.
If user wants to look for the content of each chapter, selecting the words of each
chapter on the contents can reach to each chapter. There are two buttons,
“Homepage and contents, onto the top line of first page of the each chapter. Thus,
if the user needs to check other chapters, he can click the top buttons to back the
homepage or contents. The content of each chapter can be selected too.
Therefore, when needs to checking the content inside of the chapter, click the
content words of the chapter so that can back to the initial section of the content.
In addition, there is a “To this chapter contents” button at the second page of each
content so that clicking the button can back to the contents of this chapter.
Parts to Be Greased........................... 1-17
Symbols and Marks
Symbols and marks are used in this manual to indicate what and where the special service are needed, in
case supplemental information is procedures needed for these symbols and marks, explanations will be
added to the text instead of using the symbols or marks.
Warning
Caution
Engine oil
Means that serious injury or even death may result if procedures are not
followed.
Means that equipment damages may result if procedures are not followed.
Limits to use SAE 10W-30 API SG class oil. Warranty will not cover the
damage that caused by not apply with the limited engine oil.
(Recommended oil: KING MATE G-3 oil)
1
Grease King Mate G-3 is recommended.
King Mate gear oil serials are recommended. (Bramax HYPOID GEAR OIL
Gear oil
Locking sealant
Oil seal
Renew
Brake fluid
Special tools
Correct
Wrong
Indication Indication of components.
# 140)
Apply sealant, medium strength sealant should be used unless otherwise
specified.
Apply with lubricant.。
Replace with a new part before installation.
Use recommended brake fluid DOT3 or WELLRUN brake fluid.
Special tools
Meaning correct installation.
Meaning wrong installation.
Directions
Indicates position and operation directions
Components assembly directions each other.
Indicates where the bolt installation direction, --- means that bolt cross
through the component (invisibility).
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1. GENERAL INFORMATION
General safety
Carbon monoxide
If you must run your engine, ensure the place is
well ventilated. Never run your engine in a closed
area. Run your engine in an open area, if you
have to run your engine in a closed area, be sure
to use an extractor.
Caution
Exhaust contains toxic gas which may cause one
to lose consciousness and even result in death.
Gasoline
Gasoline is a low ignition point and explosive
material. Work in a well-ventilated place, no flame
or spark should be allowed in the work place or
where gasoline is being stored.
Caution
Gasoline is highly flammable, and may explode
under some conditions, keep it away from
children.
Used engine oil
Caution
Prolonged contact with used engine oil (or
transmission oil) may cause skin cancer although
it might not be verified.
We recommend that you wash your hands with
soap and water right after contacting. Keep the
used oil beyond reach of children.
Hot components
Caution
Components of the engine and exhaust system
can become extremely hot after engine running.
They remain very hot even after the engine has
been stopped for some time. When performing
service work on these parts, wear insulated
gloves and wait until cooling off.
Battery
Caution
• Battery emits explosive gases; flame is strictly
prohibited. 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 and then go to hospital to see an
ophthalmologist.
• If you swallow it by mistake, drink a lot of
water or milk, and take some laxative such as
castor oil or vegetable oil and then go to see a
doctor.
• Keep electrolyte beyond reach of children.
Brake shoe
Do not use an air hose or a dry brush to clean
components of the brake system, use a vacuum
cleaner or the equivalent to avoid dust flying.
Caution
Inhaling brake shoe or pad ash may cause
disorders and cancer of the breathing system
Brake fluid
Caution
Spilling brake fluid on painted, plastic, or rubber
parts may cause damage to the parts. Place a
clean towel on the above-mentioned parts for
protection when servicing the brake system.
Keep the brake fluid beyond reach of children.
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Service Precautions
y Always use with Sanyang genuine parts and
recommended oils. Using non-designed parts
for Sanyang motorcycle may damage the
motorcycle.
y Special tools are designed for remove and
install of components without damaging the
parts being worked on. Using wrong tools may
result in parts damaged.
y When servicing this 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.
1. GENERAL INFORMATION
y Never bend or twist a control cable to prevent
unsmooth control and premature worn out.
y Rubber parts may become deteriorated when
old, and prone to be damaged by solvent and oil.
Check these parts before installation to make
sure that they are in good condition, replace if
necessary.
y When loosening a component which has
different sized fasteners, operate with a
diagonal pattern and work from inside out.
Loosen the small fasteners first. If the bigger
ones are loosen first, small fasteners may
receive too much stress.
y Store complex components such as
transmission parts in the proper assemble order
and tie them together with a wire for ease of
installation later.
y Clean the outside of the parts or the cover
before removing it from the motorcycle.
Otherwise, dirt and deposit accumulated on the
part's surface may fall into the engine, chassis,
or brake system to cause a damage.
y Wash and clean parts with high ignition point
solvent, and blow dry with compressed air. Pay
special attention to O-rings or oil seals because
most cleaning agents have an adverse effect on
them.
y Note the reassemble position of the important
components before disassembling them to
ensure they will be reassembled in correct
dimensions (depth, distance or position).
y Components not to be reused should be
replaced when disassembled including gaskets
metal seal rings, O-rings, oil seals, snap rings,
and split pins.
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1. GENERAL INFORMATION
y The length of bolts and screws for assemblies,
cover plates or boxes is different from one
another, be sure they are correctly installed. In
case of confusion, Insert the bolt into the hole to
compare its length with other bolts, if its length
out side the hole is the same with other bolts, it
is a correct bolt. Bolts for the same assembly
should have the same length.
y Tighten assemblies with different dimension
fasteners as follows: Tighten all the fasteners
with fingers, then tighten the big ones with
special tool first diagonally from inside toward
outside, important components should be
tightened 2 to 3 times with appropriate
increments to avoid warp unless otherwise
indicated. Bolts and fasteners should be kept
clean and dry. Do not apply oil to the threads.
y Remove residues of the old gasket or sealant
before reinstallation, grind with a grindstone if
the contact surface has any damage.
y The ends of rubber hoses (for fuel, vacuum, or
coolant) should be pushed as far as they can go
to their connections so that there is enough
room below the enlarged ends for tightening the
clamps.
Groove
Clamp
Connector
y Rubber and plastic boots should be properly
reinstalled to the original correct positions as
designed.
y When oil seal is installed, fill the groove with
grease, install the oil seal with the name of the
manufacturer facing outside, check the shaft on
which the oil seal is to be installed for
smoothness and for burrs that may damage the
oil seal.
Manufacturer's name
1-4
Boots
y The tool should be pressed against two (inner
and outer) bearing races when removing a ball
bearing. Damage may result if the tool is
pressed against only one race (either inner race
or outer race). In this case, the bearing should
be replaced. To avoid damaging the bearing,
use equal force on both races.
Both of these examples can result in
bearing damage.
To this chapter contents
y Lubricate the rotation face with specified
lubricant on the lubrication points before
assembling.
y Check if positions and operation for installed
parts is in correct and properly.
y Make sure service safety each other when
conducting by two persons.
1. GENERAL INFORMATION
y After service completed, make sure all
connection points is secured.
Battery positive (+) cable should be connected
firstly.
y And the two posts of battery have to be greased
after connected the cables.
y Make sure that the battery post caps are
located in properly after the battery posts had
been serviced.
y Note that do not let parts fall down.
y Before battery removal operation, it has to
remove the battery negative (-) cable firstly.
Notre tools like open-end wrench do not contact
with body to prevent from circuit short and
create spark.
y If fuse burned, it has to find out the cause and
solved it. And then replace with specified
capacity fuse.
Capacity
verification
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1. GENERAL INFORMATION
y When separating a connector, it locker has to
be unlocked firstly. Then, conduct the service
operation.
y Do not pull the wires as removing a connector
or wires. Hold the connector body.
y Make sure if the connector pins are bent,
extruded or loosen.
y Insert the terminal completely.
Check if the terminal is covered by the boot.
Do not let boot open facing up.
y Secure wires and wire harnesses to the frame
with respective wire bands at the designated
locations. Tighten the bands so that only the
insulated surfaces contact the wires or wire
harnesses.
y Insert the connector completely.
If there are two lockers on two connector sides,
make sure the lockers are locked in properly.
Check if any wire loose.
y Check if the connector is covered by the twin
connector boot completely and secured
properly.
y Wire band and wire harness have to be
clamped secured properly.
y Do not squeeze wires against the weld or its
clamp.
y Before terminal connection, check if the boot is
crack or the terminal is loose.
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y Do not let the wire harness contact with rotating,
moving or vibrating components as routing the
harness.
y Keep wire harnesses far away from the hot
parts.
Never Touch
1. GENERAL INFORMATION
y Protect wires or wire harnesses with electrical
tape or tube if they contact a sharp edge or
corner. Thoroughly clean the surface where
tape is to be applied.
y Secure the rubber boot firmly as applying it on
wire harness.
y Route wire harnesses to avoid sharp edges or
corners and also avoid the projected ends of
bolts and screws.
y Route harnesses so that they neither pull too
tight nor have excessive slack.
y Never use wires or harnesses which insulation
has been broken. Wrap electrical tape around
the damaged parts or replace them.
y Never clamp or squeeze the wire harness as
installing other components.
Never clamp or
squeeze the wire
harness
Never too tight
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1. GENERAL INFORMATION
y Do not let the wire harness been twisted as
installation.
y Wire harnesses routed along the handlebar
should not be pulled too tight or have excessive
slack, be rubbed against or interfere with
adjacent or surrounding parts in all steering
positions.
y With sand paper to clean rust on connector
pins/terminals if found. And then conduct
connection operation later.
Clean rust
y Before operating a test instrument, operator
should read the operation manual of the
instrument. And then, conduct test in
accordance with the instruction.
Do you know how to set the
instrument to its
measurement position and
the insert locations of its
two probes?
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Specifications
MAKER SANYANG MODEL LH18W-6
Overall Length 2064 mmFront Telescopic Fork
Overall Width 760 mm
Overall Height 1165 mmFront 100 / 80 – 16 50P/TL
Dimension
Weight
Wheel Base 1385 mm
Curb Weight
Passengers/Weight Two /110 kgMax. Speed Above 108 km/hr
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 performed 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
Item
Every
300KM
I C R
I C R
I I R
C C
R Replacement for every 1000 km
I I
I I
I I
I I
I I
I I
I I
I I R
R Replacement for every 5000 km
L
I I
I I
A I
I I
I I
I R
C
I I
I I
I I
I
I I
I A
I C
Replacement for every 2000 km
I I C
I
I I
I I
I I R
1 Month
every
1,000KM
3 month
every
3,000KM
6 month
every
6000KM
1 year
every
12,000KM
15 month
every
14,500KM
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Fuel Lines / Cable
Remove luggage box.
Remove rear carrier.
Remove body covers.
Check all lines, and replace it when they are
deterioration, damage or leaking.
Warning
Gasoline is a low ignition material so any kind of
fire is strictly prohibited as dealing it.
Acceleration Operation
Have a wide open of throttle valve as handle in
any position and release it to let back original (full
closed) position.
Check handle if its operation is smooth.
Check acceleration cable and replace it if
deteriorated, twisted or damaged.
Lubricate the cable if operation is not smooth
Measure the throttle grip free play in its flange
part.
Adjustment can be done in either end.
Secondary adjustment is conducted from top side.
Remove rubber boot, loosen fixing nut, and then
adjust it by turning the adjustment nut.
Primary adjustment is conducted from bottom
side.
Loosen fixing nut, and adjust by turning the
adjustment nut.
Tighten the fixing nut, and check acceleration
operation condition.
Free play: 2~6 mm.
2. MAINTENANCE INFORMATION
Fuel tank
Fuel filter
Fuel hose
Vacuum hose
Throttle grip
Adjustment nut
Adjustment nut
Lock nut
2~6 mm
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2. MAINTENANCE INFORMATION
Air Cleaner
Air Cleaner Element
Remove 6 screws from the air cleaner cover and
then remove the cover.
Remove 4 screws, and then remove the air
cleaner element.
Caution
The air cleaner element is made of paper so do
not soap it into water or wash it with water.
Spark Plug
Remove central cover.
Remove spark plug cap.
Clean dirt around the spark plug hole.
Remove spark plug.
Measure the spark plug gap.
Spark plug gap:0.8 mm
Carefully bend ground electrode of the plug to
adjust the gap if necessary.
Hold spark plug washer and install the spark plug
by screwing it.
Checks and adjustment must be performed when
the engine temperature is below 35℃.
Remove trunk.
Remove central cover.
Remove valve adjustment cap.
Remove cylinder head side cover.
Turn camshaft bolt in C.W. direction and let the “T”
mark on the camshaft sprocket align with cylinder
head mark so that piston is placed at TDC position
in compression stroke.
Caution
Do not turn the bolt in C.C.W. direction to prevent
from camshaft bolt looseness.
Valve clearance inspection and adjustment.
Check & adjust valve clearance with feeler gauge.
Valve clearance (IN/EX): 0.12 ± 0.02 mm
Loosen fixing nut and turn the adjustment nut for
adjustment.
2. MAINTENANCE INFORMATION
Timing mark
Caution
Re-check the valve clearance after tightened the
fixing nut.
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2. MAINTENANCE INFORMATION
Carburetor Idle Speed Adjustment
Caution
y Inspection & adjustment for idle speed have to
be performed after all parts in engine that
needed adjustment have been adjusted.
y Idle speed check and adjustment have to be
done after engine is being warm up. (It is
enough that operates engine from stop to
running for 10 minutes.)
Park the motorcycle with main stand and warm up
engine.
Connect tachometer (the wire clamp of tachometer
is connected to the high tension cable).
Open carburetor cover from the luggage box.
Turn the throttle valve stopper screw to specified
idle speed.
Specified idle speed: 1600 ± 100 rpm
Ignition cable
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 1600±100 rpm.
3. Insert the exhaust sampling pipe of exhaust
analyzer into the front section of exhaust pipe.
Adjust the air adjustment screw so that
emission value in idle speed is within standard.
4. Slightly accelerate the throttle valve and
release it immediately. Repeat this for 2~3
times.
5. Read engine RPM and value on the exhaust
analyzer. Repeat step 2 to step 4 procedures
until measured value within standard.
Emission standard CO: below 2.5~3.5%
HC: below 2000ppm
Stopper screw
Air adjustment screw
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Ignition System
Caution
y C.D.I ignition system is set by manufacturer so
it can not be adjusted.
y Ignition timing check procedure is for checking
whether CDI function is in normal or not.
Remove right side cover.
Remove ignition timing hole cap located in front
upper side of engine right cover.
Connect tachometer and ignition lamp.
Start engine.
As engine in idle speed: 1600 rpm, aim at the
mark “F” with the ignition lamp. Then, it is means
that ignition timing is correct.
Increase engine speed to 6000 rpm to check
ignition advance degree. If indent is located within
the ignition advance degrees, it is means that the
ignition advance degree is in normal.
If ignition timing is incorrect, check CDI set, pulse
rotor and pulse generator. Replace it if
malfunction of these parts is found.
2. MAINTENANCE INFORMATION
Cylinder Compression Pressure
Warm up engine.
Turn off the engine.
Remove the trunk.
Remove the central cover.
Remove spark plug cap and spark plug.
Install compression gauge.
Full open the throttle valve, and rotate the engine
by means of starter motor.
Caution
Rotate the engine until the reading in the gauge
no more increasing.
Usually, the highest pressure reading will be
obtained in 4~7 seconds.
Compression pressure: 12 ± 2 Kg/cm²
Check following items if the pressure is too low:
y Incorrect valve clearance.
y Valve leaking.
y Cylinder head leaking, piston, piston ring and
cylinder worn out.
If the pressure is too high, it means carbon
deposits in combustion chamber or piston head.
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2. MAINTENANCE INFORMATION
Drive Belt
Remove mounting bolt located under air cleaner.
Remove 7 bolts of the engine left side cover and
the cover.
Check if the belt is crack or worn out.
Replace the belt if necessary or in accord with the
periodical maintenance schedule to replace it.
Width limit: 18.5mm or above
7 bolts
Teeth
Width
Brake System (Front Disk Brake)
Brake System Hose
Make sure the brake hoses for corrosion or
leaking oil.
Brake Fluid
Check brake fluid level in the brake fluid
reservoir. If the level is lower than the LOWER
limit, add brake fluid to UPPER limit. Also check
brake system for leaking if low brake level found
Brake hose
Caution
y In order to maintain brake fluid in the reservoir
in horizontal position, do not remove the cap
until handle stop.
y Do not operate the brake lever after the cap
had been removed. Otherwise, the brake fluid
will spread out if operated the lever.
y Do not mix non-compatible brake fluid together.
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Filling Out Brake Fluid
Tighten the drain valve, and add brake fluid.
Operate the brake lever so that brake fluid
contents inside the brake system hoses.
Air Bleed Operation
Connect a transparent hose to draining valve.
Hold the brake lever and open air bleeding valve.
Perform this operation alternative until there is no
air inside the brake system hoses.
Caution
Before closing the air bleed valve, do not release
the brake lever.
Added Brake Fluid
Add brake fluid to UPPER limit lever.
Recommended brake fluid: DOT3 or DOT4 WELL
RUN brake fluid.
2. MAINTENANCE INFORMATION
Screws
Master cylinder cap
Diaphragm plate
Diaphragm
Air bubble
Drain valve
Upper
Caution
Never mix or use dirty brake fluid to prevent from
damage brake system or reducing brake
performance.
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
It is not necessary to remove brake hose when
replacing the brake lining.
Remove the brake clipper bolt, and take out the
clipper.
Caution
Do not operate the brake lever after the clipper
removed to avoid clipping the brake lining.
Pry out the brake lining with a flat driver if lining is
clipped.
Caliper bolt
Transparent hose
Brake caliper
Lining
Brake disk
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2. MAINTENANCE INFORMATION
Make sure the brake lining condition. Replace
the lining if the brake lining wear limitation groove
close to the brake disc.
Brake Lining Replacement
Compress the caliper and let the brake lining out
of the caliper mounting plate. Compress the brake
lining locking spring. Remove the inner brake
lining firstly and then remove the outer brake
lining.
Compress the brake caliper at first as installation.
Install the inner brake lining firstly, and then install
the outer brake lining.
Caution
In order to maintain brake power balance, the
brake lining must be replaced with one set.
Brake Light Switch/Starting Inhibitor
Switch
The brake lamp switch is to light up brake lamp as
brake applied.
Make sure that electrical starter can be operated
only under brake applying.
Headlight Beam Distance
Turn on main switch
Headlight beam adjustment. Turn the headlight
adjustment screw to adjust headlight beam high.
Lining
Brake lining wear
limitation groove
Master cylinder
Brake switch
Caution
y To adjust the headlight beam follows related
regulations.
y Improper headlight beam adjustment will
make in coming driver dazzled or insufficient
lighting.
Clutch Disc Wear
Run the motorcycle and increase throttle valve
opening gradually to check clutch operation.
If the motorcycle is in forward moving and shaking,
check clutch disc condition. Replace it
Adjust screw
Clutch weight
Drive plate
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Side Stand
Check side stand spring for damage or looseness.
Press down side stand and pull it with spring
gauge. If gauge reading is over 2 kg, it means that
the spring capacity is in normal.
Check if side stand set is operated smoothly.
Make sure that side stand is no bending or
deformation.
Cushion
Warning
y Do not ride the motorcycle with poor cushion.
y Looseness, wear or damage cushion will make
poor stability and drive-ability.
2. MAINTENANCE INFORMATION
Side stand
Front cushion
Press down the front cushion for several times to
check it operation.
Check if it is damage
Replace relative parts if damage found.
Tighten all nuts and bolts.
Rear Cushion
Press down the front cushion for several times to
check it operation.
Check if it is damage
Replace relative parts if damage found.
Park motorcycle with main stand.
Turn the rear wheel forcefully and check if engine
bracket bushing worn out
Replace the bushing if looseness found.
Tighten all nuts and bolts.
Nuts, Bolts Tightness
Perform periodical maintenance in accord with the
Periodical Maintenance Schedule
Check if all bolts and nuts on the frame are
tightened securely.
Check all fixing pins, snap rings, hose clamps, and
wire holders for security.
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2. MAINTENANCE INFORMATION
Wheel/Tire
Caution
Tire pressure check should be done as cold
engine.
Check if tire surface is ticked with nails, stones or
other materials.
Appointed tire pressure
Tire size Front tire Rear tire
Tire
pressure as
cold engine
(Kg/cm²)
Check if front and rear tires’ pressure is in normal.
Measure tire thread depth from tire central
surface.
Replace the tire if the depth is not come with
following specification:
Load for
under 90 Kg
Full loaded
Front tire: 1.5 mm
Rear tire: 2.0 mm
1.75 2.25
1.75 2.5
Steering Handle Top Bearing
〝△〞mark
磨損極限指標
Caution
Check all wires and cables if they are interfered
with the rotation of steering handle bar.
Lift the front wheel out of ground.
Turn handle from right to left alternative and check
if turning is smoothly.
If handle turning is uneven and bending, or the
handle can be operated in vertical direction, then
adjust the handle top bearing.
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2. MAINTENANCE INFORMATION
Special Tools List
NAME
R/L. CRANK DISASS. TOOL
NAME
NO SYM-1120000-H9A NO SYM-1130000-H9A NO SYM-9100200-H9A
CRANK SHAFT PULLER
NAME
L. CRANK SHAFT BRG. DRIVER
(ψ30mm)
CRANK CASE BUSH PULLER
NAME
NAME
CRANK SHAFT BRG. FIXING
SOCKET
NAME
NO SYM-9100210-H9A NO SYM-1120310 NO SYM-1120320
(ψ22mm)
CRANK CASE BUSH PULLER
NAME
VALVE COTTER REMOVE &
ASSEMBLY TOOL
NAME
NO SYM-1471110/20 NO SYM-9001200 NO SYM-9001209
TAPPET ADJUSTING WRENCH
NAME
TAPPET ADJUSTER
NAME
UNIVERSAL HOLDER
NAME
CLUTCH NUT WRENCH
NAME
NO SYM-2210100 NO SYM-9020200 NO SYM-2301000
CLUTCH SPRING
COMPRESSOR
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2. MAINTENANCE INFORMATION
NAME
INNER BEARING PULLER
NAME
NO SYM-6204002 NO SYM-6204001 NO SYM-3110A00
OUTER BEARING PULLER
NAME
AC.G. FLYWHEEL PULLER
NAME
(12*20*5)
WATER PUMP OIL SEAL
DRIVER
(6901)
NAME
WATER PUMP BEARING
DRIVER
NAME
WATER PUMP MECHANICL
SEAL DRIVER
NO SYM-9120500-H9A NO SYM-9100100 NO SYM-1721700-H9A
NAME
(6301)
BEARING DRIVER
NAME
(6204)
BEARING DRIVER
(6203/6004UZ)
NAME
BEARING DRIVERØ17mm
NO SYM-9610000 NO SYM-9110400 NO SYM-9620000
(27*42*7)
OIL SEAL DRIVER
NAME
(20*32*6)
OIL SEAL DRIVER
NAME
(25*40*8)
OIL SEAL DRIVER
NAME
NO SYM-9120200 NO SYM-9121600 NO SYM-9125500
2-14
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NAME Drive shaft puller NAME Drive shaft install bush NAME Extension bush (long)
NO SYM-1130000-L NO SYM-1130010 NO SYM-1130031
2. MAINTENANCE INFORMATION
NAME Extension bush (short) NAME NAME
NO SYM-1130032 NO NO
NAME NAME NAME
NO NO NO
NAME NAME NAME
NO NO NO
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2. MAINTENANCE INFORMATION
Note:
2-16
Home page
Contents
Precautions in Operation···················· 3-2
Troubleshooting ·································· 3-2
Engine Oil············································· 3-3
y Oil leaking
y Valve guide or seat worn out
y Piston ring worn out
Low oil pressure
y Low engine oil level
y Clogged in oil strainer, circuits or pipes
y Oil pump damage
Dirty oil
y No oil change in periodical
y Cylinder head gasket damage
y Piston ring worn out
3-2
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Engine Oil
Turn off engine, and park the motorcycle in flat
surface with main stand.
Check oil level with oil dipstick
So not screw the dipstick into engine as
checking.
If oil level is nearly low level, fill out
recommended oil to upper level.
Oil Change
Caution
Drain oil as engine warmed up so that make sure
oil can be drained smoothly and completely.
Place a oil pan under the motorcycle, and remove
oil drain bolt.
After drained, make sure washer can be re-used.
Install oil drain bolt.
Torque value:1.9~2.5kgf-m
3. LUBRICATION SYSTEM
Drain bolt
Engine Oil Strainer Clean
Drain engine oil out.
Remove oil strainer and spring.
Clean oil strainer.
Check if O-ring can be re-used.
Install oil strainer and spring.
Install oil strainer cap.
Torque value:1.9~2.5kgf-m
Add oil to crankcase (oil viscosity SAE 10W-30)
Recommended using King serial oil.
Engine oil capacity: 0.8L when replacing
Install dipstick, start the engine for running
several minutes.
Turn off engine, and check oil level again.
Check if engine oil leaks.
Oil strainer cap
3-3
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3. LUBRICATION SYSTEM
Oil Pump
Oil Pump Removal
Remove generator and starting gear. (Refer to
chapter 10) 。
Remove snap ring and take out oil pump driving
chain and sprocket.
Make sure that pump shaft can be rotated freely.
Remove 2 bolts on the oil pump, and then
remove oil pump.
Clip
Oil Pump Disassembly
Remove the screws on oil pump cover and
disassemble the pump as illustration shown.
Oil Pump Inspection
Check the clearance between oil pump body and
outer rotor.
Limit: 0.25 mm
2 screws
3-4
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Check clearance between inner and outer rotors.
Limit: 0.20 mm
Check clearance between rotor side face and
pump body
Limit: 0.12 mm
Oil Pump Re-assembly
Install inner and outer rotors into the pump body
Align the indent on driving shaft with that of inner
rotor. Install the driving shaft
Install fixing pin
Install the oil pump cover and fixing pin properly
3. LUBRICATION SYSTEM
Pin
1 Screw
3-5
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3. LUBRICATION SYSTEM
Oil Pump Installation
Install the oil pump, and then tighten bolts.
Torque value:0.8~1.2kgf-m
Make sure that oil pump shaft can be rotated
freely.
Install oil pump driving chain and sprocket, and
then install snap ring onto oil pump shaft.
Install starting gear and generator.
(Refer to chapter 10)
3-6
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Gear Oil
Oil level inspection
Park the motorcycle on flat surface with main
stand.
Turn off engine and remove oil inspection bolt.
Gear lubrication oil quantity has to be measured
with measure device.
If oil level is too low, add gear oil. Recommended
using King series oils.
Install oil inspection bolt.
Gear Oil Change
Remove oil level inspection bolt.
Remove drain plug and drain oil out.
Install the drain plug after drained.
Torque value: 1.0~1.4kgf-m
Make sure that the drain plug washer can be
re-used.
Add oil to specified quantity from the inspection
hole.
Gear Oil Quantity: 100 c.c. when replacing
Make sure that the bolt washer can be re-used,
and install the bolt.
Start engine and run engine for 2-3 minutes.
Turn off engine and make sure that oil level is in
correct level.
Make sure that no oil leaking.
Air Cleaner..........................................4-11
4
To fuel vapor separator
4-1
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4. FUEL SYSTEM
Precautions in Operation
General Information
Warning
Gasoline is a low ignition point and explosive materials, so always work in a well-ventilated place and
strictly prohibit flame when working with gasoline.
Cautions
y Do not bend off throttle cable. Damaged throttle cable will make unstable drive-ability.
y When disassembling fuel system parts, pay attention to O-ring position, replace with new one as
re-assembly
y There is a drain screw in the float chamber for draining residual gasoline.
y Do not disassemble auto by-starter and air cut valve arbitrarily.
Specification
ITEM LH12W-6 LH18W-6
Carburetor diameter 24 mm 25 mm
I.D. number CVK039 CVK066
Fuel level 20.5 mm 20.5 mm
Main injector #105 #108
Idle injector #35 #35
Idle speed 1600±100 rpm 1600±100 rpm
Throttle handle clearance 2~6 mm 2~6 mm
Pilot screw 2 1/4 turns 1 1/2 turns
Tool
Special service tools
Vacuum/air pressure pump
Fuel level gauge
4-2
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Trouble Diagnosis
Poor engine start
y No fuel in fuel tank
y Clogged fuel tube
y Too much fuel in cylinder
y No spark from spark plug(malfunction of ignition
system )
y Clogged air cleaner
y Malfunction of auto by-starter
y Malfunction of throttle operation
Stall after started
y Malfunction of auto by-starter
y Incorrect ignition timing
y Malfunction of carburetor
y Dirty engine oil
y Air existing in intake system
y Incorrect idle speed
4. FUEL SYSTEM
Mixture too lean
y Clogged fuel injector
y Vacuum piston stick and closed
y Malfunction of float valve
y Fuel level too low in float chamber
y Clogged fuel tank cap vent
y Clogged fuel filter
y Obstructed fuel pipe
y Clogged air vent hose
y Air existing in intake system
Mixture too rich
y Clogged air injector
y Malfunction of float valve
y Fuel level too high in float chamber
y Malfunction of auto by-starter
y Dirty air cleaner
Rough idle
y Malfunction of ignition system
y Incorrect idle speed
y Malfunction of carburetor
y Dirty fuel
Intermittently misfire as acceleration
y Malfunction of ignition system
Late ignition timing
y Malfunction of ignition system
y Malfunction of carburetor
Power insufficiency and fuel consuming
y Fuel system clogged
y Malfunction of ignition system
4-3
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4. FUEL SYSTEM
Carburetor removal
Remove the luggage box.
Loosen the adjustment nut and fixing nut of throttle
valve cable, and release the cable from carburetor.
Disconnect automatic by-starter connector.
Release the clamp strip of air cleaner.
Remove fuel pipe, vacuum hose.
Release the clamp strip of carburetor insulator.
Vacuum chamber
Auto by-starter
Air cleaner clamp
Vacuum hose
Throttle cable
Air cleaner clamp
Fuel pipe
2 Screws
Removal
Loosen drain screw, and drain out residual fuel in
float chamber.
Remove 2 screws of vacuum chamber cover and
the cover.
Remove compress spring and vacuum piston.
Spring
4-4
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Check if the vacuum piston for wear out, crack or
other damage.
Check if the diaphragm for damage or crack.
Installation
Install needle, spring and needle seat to vacuum
piston.
Install vacuum piston to carburetor body and align
the indent on the diaphragm.
Install compress spring.
Install vacuum chamber cover and tighten 2
screws.
4. FUEL SYSTEM
Needle seat
Piston
Needle
Spring
2 Screws
Caution
y Do not damage vacuum diaphragm.
y When tightening the vacuum chamber screw,
hold down vacuum piston.
4-5
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4. FUEL SYSTEM
Air Cut-Off Valve
Inspection
Disconnect vacuum hose and air vent hose from
the air cut-off valve.
Connect a hose from vacuum hose connector to
vacuum pump.
Connect air pump to air vent hose.
Apply with specified vacuum to air cut-off valve.
Vacuum value: 420~500 mm-Hg
Pump compressed air from air pump to air vent
hose.
Caution
The vacuum can not be over 600 mm-Hg. Or the
air cut-off will be damaged.
If the valve is in normal, it will restrict air-flow.
If air-flow is no restrict, replace carburetor
assembly.
4-6
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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 starter with a new one if
resistance value exceeds standard.
Remove carburetor, allow it to cool off for 30
minutes.
Connect a pressure tester from air pump.
Connect by-starter 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 by-starter
circuit with compressed air. If air flows 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.
4. FUEL SYSTEM
Screw ×1
Auto by– starter
Plate
Screw ×1
Installation
Install auto by-starter to the bottom of 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.
Needle
4-7
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4. FUEL SYSTEM
Float Chamber
Disassembly
Remove 3 mounting screws and remove float
chamber cover.
Remove the float pin and float.
Checking
Check float valve and valve seat for damage,
blocking.
Check float valve for wearing, and check valve
seat face for wear, dirt.
Caution
In case of worn out or dirt, the float valve and
valve seat will not tightly close causing fuel level
to increase and as a result, fuel flooding. A worn
out or dirty float valve must be replaced with a
new a new one.
Remove main jet, fuel needle jet holder, needle jet,
slow jet, pilot screw.
Float
FloatPin
Needle jet
Pin
3 Screws
1 Screw
Float valve
Slow jet
Caution
Take care not to damage jets and adjust screw.
y Before removing adjustment screw, turn it all
the way down and note the number of turns.
y Do not turn adjust screw forcefully to avoid
damaging valve seat face.
Clean jets with cleaning fluid. Then use
compressed air to blow the dirt off.
Blow carburetor body passages with compressed
air.
Needle jet holder
Main jet
Needle jet
Slow jet
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Assembly
Install main jet, fuel needle jet holder, fuel needle
jet slow jet and pilot screw.
Caution
Set the pilot screw in according to number of turns
noted before it was removed.
Install the float valve, float, and float pin.
Checking fuel level
Caution
y Check again to ensure float valve, float for
proper installation.
y To ensure correct measurement, position the
float meter in such a way so that float chamber
face is vertical to the main jet.
Fuel level: 20.5 mm
Installation of carburetor
Install carburetor in the reverse order of removal.
Following adjustments must be made after
installation.
˙Throttle cable adjustment.
˙Idle adjustment
4. FUEL SYSTEM
Pilot screw
Float gauge
Adjustment of pilot screw
Caution
y Pilot screw was set at factory, so no
adjustment is needed. Note the number of
turns it takes to screw it all the way in for ease
of installation.
y The main stand must be used to support the
motorcycle to perform the adjustments.
Use a tachometer when adjusting engine RPM.
Screw in adjustment screw gently, then back up to
standard turns.
Standard turns:2±1/2(1 1/2~2 1/2) turns
Warm up engine, adjust the stopper screw of
throttle valve to standard RPM.
Idle speed rpm: 1600 ± 100 rpm
Connect the hose of exhaust analyzer to exhaust
front end. Press test key on the analyzer.
Adjust the pilot screw and read CO reading on the
analyzer
CO standard value: 1.0~1.5 %
Accelerate in gradual increments, make sure rpm
and CO value are in standard value after engine
running in stable. If rpm and CO value fluctuated,
repeat the procedures described above for
adjusting to standard value.
Throttle cable adjust nut
Idle adjustment screw
Pilot screw
4-9
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4. FUEL SYSTEM
Fuel Tank
Fuel unit removal
Open the seat.
Remove the luggage box (6 bolts and 1 screw).
Remove rear carrier (4 bolts).)
Remove body cover.
Disconnect fuel unit connector.
Remove fuel unit (4 screws).
Caution
˙Do not bend the float arm of fuel unit
˙Do not fill out too much fuel to fuel tank.
Fuel unit inspection. (Refer to electrical equipment
chapter 17)
Fuel unit installation
Install the gauge in the reverse order of removal.
Fuel unit connector
Caution
Do not forget to install the gasket of fuel unit or
damage it.
Fuel tank removal
Remove the Fuel cut valve assembly and Fuel
tube.
Remove fuel tank (4 screws).
Fuel cut valve
Fuel tube
4 bolts
Installation
Install the tank in the reverse order of removal.
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Air Cleaner
Removal
Open the seat.
Remove the luggage box (6 bolts and 1 screw).
Loosen the clamp strip of air cleaner.
Remove the Vapor hose.
Remove the Air cleaner (2 bolts).
Installation
Install the tank in the reverse order of removal.
4. FUEL SYSTEM
Clamp strip of air cleaner
Cleaning air cleaner element
Remove air cleaner cover (6 screws).
Remove the Air cleaner element. (Screw×4)
With compressed air to cleaning dirty around the
element. Replace it if it is too dirty to clean.
6 Screws
Screw×4
Caution
The air cleaner element is made of paper so do
not soap it into water or wash it with water.
4-11
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4. FUEL SYSTEM
Notes:
4-12
Home page
Contents
Precautions in Operation....................5-1
Removal of Engine ..............................5-2
y The engine has to be supported with special service tools that can be lifted or adjustable.
y The following parts can be serviced as engine mounted on frame.
y Carburetor.
y Driving pulley, driving belt, clutch, and driving disc assembly.
y Final gear reduction mechanism.
Open seat and remove the luggage box (6 bolts
and 1 screw).
Remove rear carrier (4 bolts).
Remove battery cover (2 screws).
Remove battery negative (-) post.
Remove battery positive (+) post.
Remove tail light connector.
Remove right and left body cover (2 bolts).
Disconnect the auto by-starter wire connector.
Disconnect A.C.G wire connectors.
Remove starter motor wire from relay.
Remove spark plug cap.
Remove fuel pipe, vacuum tube and throttle valve
wire from carburetor.
Loosen the screw of air cleaner duct strip, and
then remove the duct.
A.C.G wire coupler
Spark plug cap
Auto by-starter &
AC. G. coupler
Starter relay
5-2
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Remove water hoses from water pump.
Remove the thermo-sensor wire.
Remove the muffler (3 bolts, 2 nuts).
Remove rear inner fender
Water hoses
Water pump
Thermo-sensor wire
3 bolts
Right side
5. ENGINE REMOVAL
2 nuts
Left side
2 Bolts
1 Bolt
5-3
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5. ENGINE REMOVAL
Remove the mounting bolt of right-rear cushion.
Remove the rear fork mounting bolt. (2 bolts)
Remove rear wheel mounting nut.
Remove rear fork and collars.
Remove rear wheel.
Remove the mounting bolt of left-rear cushion.
Rear wheel axle nut
2 Bolts
5-4
Left-rear cushion bolt
To this chapter contents
Remove the right and left side engine hanger
mounting bolts and nuts, then remove engine.
Caution
˙Support engine and frame separately with
special supporters to prevent from engine or
frame falling down.
Engine Hanger removal
5. ENGINE REMOVAL
Left side
Engine hanger nut and bolt
Right side
Engine mounting nut and bolt
Remove the engine mounting bolt and nut, then
remove engine hanger.
Engine mounting nut and bolt
5-5
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5. ENGINE REMOVAL
Removal of Engine Hanger Bush
Check if engine hanger bush and cushion rubber
bush for damage.
Pressing out
If engine hanger and the rear cushion rubber bush
damaged. Then, with the bush remover / presser,
Ø 30mm & Ø 22mm, to press the bush out, and
replace it with new one.
Engine hanger bush: ψ 30mm
Rear cushion bush: ψ 22mm
Place the detent section of the bush remover
toward the bush, and drive both the pressing ring
and bolt in to press the bush out.
Pressing In
Bush
Place the flat section of the remover toward the
bush, and then drive the bush, pressing ring, and
bolt in to install the bush.
5-6
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Engine Hanger Installation
Install engine hanger onto engine.
Install engine mounting bolts & nuts and then
tighten the nuts.
Torque value: 4.0~5.0kgf-m
Engine Installation
Check if the bush of engine hanger parts and
cushion for damage.
Install engine in the reverse procedures of
removal.
Caution
y Pay attention of foot & hand safety as engine
installation to avoid hurting.
y Do not bend or twist wires.
y Cables wires have to be routed in accordance
Mechanism Diagram··························· 6-1
Precautions in Operation··················· 6-2
Troubleshooting·································· 6-3
Cylinder Head Removal······················ 6-4
Cylinder Head Disassembly··············· 6-6
Cylinder Head Inspection··················· 6-7
Mechanism Diagram
0.8~1.2kgf-m
6. CYLINDER HEAD/VALVE
Valve Stem Replacement··················· 6-8
Valve Seat Inspection and Service··· 6-9
Cylinder Head Reassembly··············· 6-11
Cylinder Head Installation················· 6-12
Valve Clearance Adjustment············· 6-14
6
0.8~1.2kgf-m
2.0~2.4kgf-m
1.0~1.2kgf-m
2.0~2.4kgf-m
6-1
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6. CYLINDER HEAD/VALVE
Precautions in Operation
General Information
y This chapter is contained maintenance and service for cylinder head, valve, and camshaft as well as
rocker arm.
y Cylinder head service can be carried out when engine is in frame.
Specification
Item Standard Limit
Compression pressure 12+/2 kg/cm2 ---
Intake 30.800~30.920 3.075 Camshaft Height of cam lobe
Exhaust 30.411~30.531 30.26
ID of valve rocker arm 12.000~12.018 12.10 Rocker arm
OD of valve rocker arm shaft 11.966~11.984 11.910
Valve
Guide seat 5.000~5.012 5.030
Intake 4.975~4.990 4.900 OD of valve stem
Exhaust 4.955~4.970 4.900
Intake 0.010~0.037 0.080 Clearance between
valve stem and guide
Free length of valve spring 35.000 31.500
Valve seat width 1.000 1.6
Tilt angle of cylinder head --- 0.05
Exhaust 0.030~0.057 0.100
Torque Value
Cylinder head bolt (LH) 2.0~2.4kgf-m
Cylinder head Nut 2.0~2.4kgf-m
Sealing bolt of cam chain auto-tensioner 0.8~1.2kgf-m
Bolt of cam chain auto-tensioner 1.2~1.6kgf-m
Cam sprocket cover bolts 0.8~1.2kgf-m
Cam sprocket bolt 0.8~1.2kgf-m
Spark plug 1.0~1.2kgf-m
Tools
Special service tools
Valve reamer: 5.0mm
Valve guide driver: 5.0mm
Valve spring compressor
6-2
To this chapter contents
6. CYLINDER HEAD/VALVE
Troubleshooting
Engine performance will be effected by troubles on engine top parts. The trouble usually can be
determined or by performing cylinder compression test and judging the abnormal noise generated.
Low compression pressure
1. Valve
y Improper valve adjustment
y Burnt or bent valve
y Improper valve timing
y Valve spring damage
y Valve carbon deposit.
2. Cylinder head
y Cylinder head gasket leaking or damage
y Tilt or crack cylinder
3. Piston
y Piston ring worn out.
High compression pressure
y Too much carbon deposit on combustion chamber or piston head
Noise
y Improper valve clearance adjustment
y Burnt valve or damaged valve spring
y Camshaft wear out or damage
y Chain wear out or looseness
y Auto-tensioner wear out or damage
y Camshaft sprocket
y Rocker arm or rocker arm shaft wear out
6-3
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6. CYLINDER HEAD/VALVE
Cylinder Head Removal
Remove seat, luggage box and body cover.
Remove engine. (Refer to chapter 5)
Remove the clamp strip bolt of carburetor, and
disconnect vacuum tube from the carburetor
insulator.
Remove Air Injection system (AI) pipe mounting
bolt.
Remove 1 bolt of thermostat and then remove the
thermostat.
Remove hole cap for the adjustment bolt of cam
chain tensioner, and then loosen the tensioner by
turning a flat-driver in C.W direction.
Remove the side cover mounting blots of cylinder
head, and then take out the side cover.
Remove cam sprocket bolts and then remove the
sprocket by prying chain out.
Vacuum tube
AI. Pipe bolt
Hole cap of adjustment bolt
Clamp strip
Thermostat bolt
2 bolts
2 bolts
6-4
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Remove the 2 cylinder head mounting bolts from
cylinder head right side, and then remove 4 nuts
and washers from cylinder head upper side.
Remove the cylinder head.
Remove 2 bolts of carburetor insulator and then
take the insulator out.
Remove cylinder head gasket and 2 dowel pins.
Remove chain guide.
Clean up residues from the matching surfaces of
cylinder and cylinder head.
6. CYLINDER HEAD/VALVE
2 Insulator bolts
Cylinder head mounting
Carburetor insulator
4 Nuts
Dowel pin
Caution
y Do not damage the matching surfaces of
cylinder and cylinder head.
y Avoid residues of gasket or foreign materials
falling into crankcase as cleaning.
Chain guide
Gasket
6-5
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6. CYLINDER HEAD/VALVE
Cylinder Head Disassembly
Remove the hole cap of intake & exhaust valve
clearance adjustment. There are 6 bolts. Then,
remove the cap.
Remove the rocker arm pin stopper plate, and
then screw a 5mm bolt into the rocker arm pin.
Finally, remove the pin and the rocker arm.
Screw a 6 mm bolt into cam sprocket mounting
bolt hole, and then pull the camshaft out.
Use a valve compressor to press the valve spring.
Stopper plate bolt
Caution
y In order to avoid loosing spring elasticity, do not
press the spring too much. Thus, press length
is based on the valve cotter in which can be
removed.
Special Service Tool:
Valve spring remover (SYM-1471110)
Valve spring installer (SYM-1471120)
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 surface of cylinder
head.
6-6
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Cylinder Head Inspection
Check if spark plug and valve holes are cracked.
Measure cylinder head warp with a straightedge
and thickness gauge.
Service limit: 0.5 mm
Valve spring free length
Measure the free length of intake and exhaust
valve springs.
Service limit: 28.90 mm
Valve stem
Check if valve stems are bend, crack or burn.
Check the operation condition of valve stem in
valve guide, and measure & record the valve stem
outer diameter.
Service Limit: IN: 4.90 mm
EX: 4.90 mm
Valve guide
Caution
Before measuring the valve guide, clean carbon
deposits with reamer.
Tool: 5.0 mm valve guide reamer
Measure and record each valve guide inner
diameters.
Service limit: 5.03 mm
The difference that the inner diameter of valve
guide deducts the outer diameter of valve stem is
the clearance between the valve stem and valve
guide.
Service Limit: IN→0.08 mm
EX→0.10 mm
6. CYLINDER HEAD/VALVE
5.0 mm valve guide reamer
6-7
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6. CYLINDER HEAD/VALVE
Caution
If clearance between valve stem and valve guide
exceeded service limit, check whether the new
clearance that only replaces new valve guide is
within service limit or not. If so, replace valve
guide.
Correct it with reamer after replacement.
If clearance still exceeds service limit after
replaced valve guide, replace valve stem too.
Caution
It has to correct valve seat when replacing valve
guide.
Valve Stem Replacement
Heat up cylinder head to 100~150 ℃ with heated
plate or toaster.
Caution
y Do not let torch heat cylinder head directly.
Otherwise, the cylinder head may be deformed
as heating it.
y Wear on a pair of glove to protect your hands
when operating.
Hold the cylinder head, and then press out old
valve guide from combustion chamber side.
Valve guide driver
5.0mm
Tool: Valve guide driver: 5.0 mm
Caution
y Check if new valve guide is deformation after
pressed it in.
y When pressing in the new valve guide, cylinder
head still have to be kept in 100~150
Adjust the valve guide driver and let valve guide
height is in 13 mm.
Press in new valve guide from rocker arm side.
Tool: Valve guide driver: 5.0 mm
Wait for the cylinder head cooling down to room
temperature, and then correct the new valve guide
with reamer.
℃.
Caution
y Using cutting oil when correcting valve guide
with a reamer.
y Turn the reamer in same direction when it be
inserted or rotated.
Correct valve seat, and clean up all metal residues
from cylinder head.
Tool: Valve guide reamer: 5.0 mm
Valve guide driver
5.0 mm
Valve guide reamer 5.0 mm
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Valve Seat Inspection and Service
Clean up all carbon deposits onto intake and
exhaust valves.
Apply with emery slightly onto valve contact face.
Grind valve seat with a rubber hose or other
manual grinding tool.
Caution
y Do not let emery enter into between valve stem
and valve guide.
y Clean up the emery after corrected, and apply
with engine oil onto contact faces of valve and
valve seat.
Remove the valve and check its contact face.
Caution
Replace the valve with new one if valve seal is
roughness, wear out, or incomplete contacted
with valve seat.
Valve seat inspection
If the valve seat is too width, narrow or rough,
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 ground with valve
seat chamfer cutter.
Refer to operation manual of the valve seat
chamfer cutter.
Use 45° valve seat chamfer cutter to cut any rough
or uneven surface from valve seat.
Caution
After valve guide had been replaced, it has to be
ground with 45° valve seal chamfer cutter to
correct its seat face.
Use 32° cutter to cut a quarter upper part out.
6. CYLINDER HEAD/VALVE
Valve seat width
Roughness
45°
Old valve seat width
32°
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6. CYLINDER HEAD/VALVE
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
Make sure that all roughness and uneven faces
had been ground.
Grind valve seat again if necessary.
Coat the valve seat surface with red paint.
Install the valve through valve guide until the valve
contacting with valve seat, slightly press down the
valve but do not rotate it so that a seal track will be
created on contact surface.
Contact surface too high
Old valve seat width
60°
1.0mm
Old valve seat width
45°
Caution
The contact surfaces of valve and valve seat are
very important to the valve sealing capacity.
If the contact surface too high, grind the valve seat
with 32° cutter.
Then, grind the valve seat to specified width.
If the contact surface too low, grind the valve seat
with 60° cutter.
Then, grind the valve seat to specified width.
6-10
Contact surface too low
32°
Old valve seat width
60°
V
To this chapter contents
After the valve seat ground, coat valve seat
surface with emery and then slightly press the
ground surface.
Clean up all emery coated onto cylinder and valve
after ground.
Cylinder Head Reassembly
Lubricate valve stem with engine oil, and then
insert the valve into valve guide.
Install new valve stem oil seal.
Install valve springs and retainers.
Caution
The closed coils of valve spring should face down
to combustion chamber.
Use valve spring compressor to press valve
spring.
6. CYLINDER HEAD/VALVE
Intake valve
Valve spring retainer
Exhaust valve
alve cotter
Valve stem seal
Valve spring
Caution
In order to avoid damaging the valve stem and
the cylinder head, in the combustion chamber
place a rag between the valve spring
remover/installer as compressing the valve spring
directly.
Special Service Tool:
Valve spring remover (SYM-1471110)
Valve spring installer (SYM-1471120)
Tap valve stem to make valve retainer and valve
stem sealing properly.
Caution
Place and hold cylinder head on to working table
so that can prevent from valve damaged.
6-11
To this chapter contents
6. CYLINDER HEAD/VALVE
Cylinder Head Installation
Install a new O-ring into the indent of carburetor
insulator, and then install the insulator onto
cylinder head with 2 bolts.
Install camshaft into cylinder head, and align
rocker pin with rocker arm pin hole. Then, insert
the rocker arm pin.
Install rocker arm pin mounting plate.
Clean up all residues and foreign materials onto
the matching surfaces of both cylinder and
cylinder head.
Install chain guide.
Install 2 set pins and cylinder head gasket.
Caution
Do not damage the matching surfaces of cylinder
and cylinder head.
Avoid residues of gasket or foreign materials
falling into crankcase as cleaning.
Loosen the tensioner by turning a flat-driver in
C.W direction.
Install cylinder head.
Chain guide
Carburetor insulator
Stopper plate bolt
Dowel pin
Gasket
6-12
To this chapter contents
Tighten 4 nuts and washers on the cylinder head
upper side, and then tighten 2 cylinder head
mounting bolts of cylinder head side cover.
Torque value: 2.0~2.4kgf-m
Install and tighten spark plug
Torque value: 2.0~2.4kgf-m
Caution
This model is equipped with more precision
4-valve mechanism so its tighten torque can not
be exceeded standard value in order to avoid
causing cylinder head deformation, engine noise
and leaking so that motorcycle’s performance be
effected.
Install cam chain on to sprocket and align the
timing mark on the sprocket with that of cylinder
head.
Align sprocket bolt hole with camshaft bolt hole.
Tighten the sprocket mounting bolt.
6. CYLINDER HEAD/VALVE
2 Insulator bolts
Cylinder head mounting bolts
4 Nuts
Caution
Make sure timing marks are matched.
Install a new O-ring onto thermostat and tighten its
mounting bolts.
Loosen sprocket chain tensioner and let it contact
with chain plate tightly. Tighten the bolt cap of
tensioner adjustment hole.
Install Air Injection system (AI) pipe. (2 bolts)
Install carburetor insulator onto carburetor and
tighten clamp strip bolt. Install the vacuum hose
of carburetor insulator.
Hole cap of adjustment bolt
Vacuum tube
Timing mark
Thermostat bolt
Clamp strip
AI. Pipe bolts
6-13
To this chapter contents
6. CYLINDER HEAD/VALVE
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: IN 0.12 ± 0.02 mm
EX 0.12 ± 0.02 mm
Install the valve clearance adjustment hole cap.
(3 bolts)
Caution
The gasket is paper type. In case of broken,
replace it and clean the Remnant gasket.
Start the engine after assembly. Remove the
intake valve adjustment hole cap and make sure
that engine oil flows onto the cylinder head.
Stop the engine after confirmed, and then install
the intake valve adjustment hole cap.
Install the seat, luggage box and the body cover.
Caution
y If lubricant does not flow to cylinder head,
engine components will be worn out seriously.
Thus, it must be confirmed.
y When checking lubricant flowing condition, run
the engine in idle speed. Do not accelerate
engine speed.
6-14
Home page
Contents
7. CYLINDER/PISTON
Mechanism Diagram······························7-1
Precautions in Operation ······················7-2
Trouble Diagnosis··································7-2
Cylinder Removal···································7-3
y Both cylinder and piston service cannot be carried out when engine mounted on frame.
Specification Unit:mm
LH12W & LH18W
Item Standard Limit
Cylinder
Piston/
Piston ring
OD of piston pin 14.960~15.000 14.930
Clearance between piston and piston pin 0.002~0.014 0.020
ID of connecting rod small-end 15.016~15.034 15.060
ID ( LA18W not included) 56.995~57.015 57.016
Bend - 0.050
Clearance between piston
rings
Ring-end gap
OD of piston ( LA18W not included) 56.985~57.005 56.900
Clearance between piston and cylinder 0.010~0.040 0.100
ID of piston pin boss 15.002~15.008 15.040
Top ring 0.015~0.050 0.090
nd
ring 0.015~0.050 0.090
2
Top ring 0.150~0.300 0.500
2nd ring 0.300~0.450 0.650
Oil ring side rail 0.200~0.700 -
LH18W
Item Standard Limit
Cylinder ID 60.995~61.015 61.016
Piston OD of piston 60.985~61.005 60.900
Trouble Diagnosis
Low or Unstable Compression Pressure
y Cylinder or piston ring worn out
Knock or Noise
y Cylinder or piston ring worn out
y Carbon deposits on cylinder head top-side
y Piston pin hole and piston pin wear out
Smoking in Exhaust Pipe
y Piston or piston ring worn out
y Piston ring installation improperly
y Cylinder or piston damage
Engine Overheat
y Carbon deposits on cylinder head top side
y Cooling pipe clogged or not enough in coolant
flow
7-2
To this chapter contents
7. CYLINDER/PISTON
Cylinder Removal
Remove cylinder head (refer to chapter 6).
Remove coolant hose from cylinder.
Remove cylinder.
Remove cylinder gasket and dowel pin.
Cover the holes of crankcase and cam chain with
a piece of cloth.
Clean up all residues or foreign materials from
the two matching surfaces of cylinder and
crankcase.
Coolant hose
Caution
y Soap the residues into solvent so that the
residues can be removed more easily.
Inspection
Check if the inner diameter of cylinder is wear out
or damaged.
In the 3 positions, top, center and bottom, of
cylinder, measure the X and Y values respective
in the cylinder.
Service limit: LH12W: 57.016
LH18W: 61.10 mm
Check cylinder if warp.
Service limit: 0.05 mm
Top
Center
Bottom
7-3
To this chapter contents
7. CYLINDER/PISTON
Piston Removal
Plug crankcase opening with a cleaning cloth to
prevent from piston pin snap ring or other foreign
materials 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.
Inspection
Measure clearance between piston ring and its
grooves.
Service Limit: Top ring: 0.09 mm
nd
2
ring: 0.09 mm
Remove piston rings
Check if the piston rings are damaged or its
grooves are worn.
Caution
Pay attention to remove piston rings because
they are fragile.
Place piston rings respective into cylinder below
20 mm of cylinder top. In order to keep the piston
rings in horizontal level in cylinder, push the rings
with piston.
Service Limit: Top ring: 0.50 mm
nd
ring: 0.65 mm
2
7-4
To this chapter contents
7. CYLINDER/PISTON
Measure the outer diameter of piston pin.
Service Limit: 15.040 mm
Measure the inner diameter of connecting rod
small end.
Service Limit: 15.06 mm
Measure the inner diameter of piston pin hole.
Service Limit: 15.04 mm
Calculate clearance between piston pin and its
hole.
Service Limit: 0.02 mm
Measure piston outer diameter.
Caution
The measurement position is 10 mm distance
from piston bottom side, and 90° to piston pin.
Service limit:60.90 mm
Compare measured value with service limit to
calculate the clearance between piston and
cylinder.
7-5
To this chapter contents
7. CYLINDER/PISTON
Piston Ring Installation
Clean up piston top, ring groove, and piston surface.
Install the piston ring onto piston carefully.
Place the openings of piston ring as diagram shown.
Caution
y Do not damage piston and piston rings as installation.
y All marks on the piston rings must be forwarded to up side.
y Make sure that all piston rings can be rotated freely after installed.
Top ring
nd
2
ring
Oil ring
Top groove
nd
2
groove
Oil groove
7-6
To this chapter contents
7. CYLINDER/PISTON
Piston Installation
Install piston and piston pin, and place the IN
marks on the piston top side forward to intake
valve.
Install new piston pin snap ring.
Caution
y Do not let the opening of piston pin snap ring
align with the opening piston ring.
y Place a piece of cloth between piston and
crankcase in order to prevent snap ring from
falling into crankcase as operation.
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
Soap the residues into solvent so that the
residues can be removed more easily.
Install dowel 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
Do not push piston into cylinder forcefully
because piston and piston rings will be
damaged.。
Install coolant hose onto cylinder.
Install cylinder head (refer to Chapter 6).
y Drive face, clutch outer, and driven pulley can be serviced on the motorcycle.
y Driving belt and driving pulley must be free of grease.
Specification Unit:mm
Item Standard value (mm) Limit (mm)
Driving belt width 19.000 17.500
ID of drive face boss 27.000~27.021 27.060
OD of drive face 26.970~26.990 26.940
OD of roller 19.950~20.100 19.500
ID of clutch outer 130.000~130.200 130.500
Thickness of clutch weight 4.000~4.100 2.000
Free length of driven pulley spring 88.300 83.200
OD of driven pulley 33.965~33.985 33.940
ID of drive face 34.000~34.025 34.060
Torque value
y Driven face nut: 5.0~6.0kgf-m
y Clutch outer nut: 5.0~6.0kgf-m
Special Service Tools
Clutch spring compressor: SYM-2301000
Inner bearing puller:
Clutch nut wrench 39 x 41 mm:
Universal holder:
Bearing driver:
SYM-6204002
SYM-9020200
SYM-2210100
SYM-9100100
Trouble Diagnosis
Engine can be started but motorcycle can
not be moved
1. Worn driving Belt
2. Worn drive face
3. Worn or damaged clutch weight
4. Broken driven pulley
Insufficient horsepower or poor high
speed performance
1. Worn driving belt
2. Insufficient spring force of driven pulley
3. Worn roller
4. Driven pulley operation un-smoothly
Shudder or misfire when driving
1. Broken clutch weight
2. Worn clutch weight
8-2
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Left Crankcase Cover
Left crankcase cover removal
Remove body cover.
Remove air cleaner. (2 bolts)
Remove L crankcase cover. (7 bolts)
Left crankcase cover install
Install left crankcase cover in the reverse
procedures of removal.
8-3
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Driving Belt
Removal
Remove left crankcase cover
Hold drive face with universal holder, and remove
nut and drive face.
Hold clutch outer with universal holder, and
remove nut and clutch outer.
Caution
y Using special service tools for tightening or
loosening the nut.
y Fixed rear wheel or rear brake will damage
reduction gear system.
Universal holder
Drive belt
Nut
Push the driving belt into belt groove as diagram
shown so that the belt can be loosened, and then
remove the driven pulley.
Remove driven pulley. Do not remove driving
belt.
Remove the driving belt from the groove of driven
pulley.
Inspection
Check the driving belt for crack or wear. Replace
it if necessary.
Measure the width of driving belt as diagram
shown.
Service Limit: 17.5 mm
Replace the belt if exceeds the service limit.
Caution
Universal holder
Belt tooth
Width
y Using the genuine parts for replacement.
y The surfaces of driving belt or pulley must be
free of grease.
y Clean up all grease or dirt before installation.
8-4
To this chapter contents
Installation
Caution
Pull out driven face to avoid it closing.
Install driving belt onto driven pulley.
Install the driven pulley that has installed the belt
onto drive shaft.
On the drive belt another end to the movable drive
face.
Install the clutch outer with universal holder, and
then tighten nut to specified torque value.
Torque value: 5.0~6.0kgf-m
8. V-BELT DRIVING SYSTEM/KICK STARTER
Driven face
Clutch outer
Nut
Universal holder
Install the drive face with universal holder, and
then tighten nut to specified torque value.
Torque value: 5.0~6.0kgf-m
Universal holder
8-5
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Drive Face
Removal
Remove left crankcase cover.
Hold generator flywheel with universal holder, and
then remove drive face nut.
Remove drive face.
Remove driving belt and movable drive face comp
from crankshaft.
Remove ramp plate.
Universal holder
Crankshaft
Ramp plate
Movable drive face
Drive face boss
Remove weight rollers from movable drive face.
Movable drive face
Weight roller
8-6
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Inspection
The weight rollers are to press movable drive face
by means of centrifuge force.
Thus, if weight rollers are worn out or damaged,
the centrifuge force will be effected.
Check if rollers are worn or damaged. Replace it
if necessary.
Measure each roller’s outer diameter. Replace it if
exceed the service limit.
Service limit: 19.50 mm
Weight: 14.5g
Check if drive face boss is worn or damaged and
replace it if necessary.
Measure the outer diameter of movable drive face,
and replace it if it exceed service limit.
Service limit: 26.94 mm
Weight roller
Movable drive face
Drive face boss
Measure the inner diameter of movable drive face,
and replace it if it exceed service limit.
Service limit: 27.06 mm
Reassembly/installation
Install weight rollers.
Caution
The weight roller two end surfaces are not
certainly same. In order to lengthen the roller
life and prevented exceptionally wears the
occurrence, Please end surface of the closure
surface counter clockwise assembles onto
movable drive face.
Install ramp plate.
Weight roller
Guide collar
Closure surface
Ramp plate
8-7
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
With 4~5g grease spreads wipes drives in the
movable drive face axis hole.
Install drive face boss.
Caution
The movable drive face surface has to be free of
grease. Clean it with cleaning solvent.
Install movable drive face comp. onto crankshaft.
Movable drive face
Crank shaft
Driven pulley installation
Press driving belt into pulley groove, and then pull
the belt onto drive shaft.
Install drive face, washer and nut.
Press down
Drive belt
Drive face boss
Drive face boss
Nut
Caution
Make sure that two sides of pulley surfaces have
to be free of grease. Clean it with cleaning
solvent.
Hold drive face with universal holder.
Tighten nut to specified torque.
Torque value: 5.0~6.0kgf-m
Install left crankcase cover.
8-8
Drive face
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Clutch Outer/Driven Pulley
Disassembly
Remove drive belt and clutch outer/driven pulley.
Install clutch spring compressor onto the pulley
assembly, and operate the compressor to let the
wrench be installed more easily.
Caution
Do not press the compressor too much.
Hold the clutch spring compressor onto bench vise,
and then remove mounting nut with special service
tool.
Release the clutch spring compressor and remove
clutch weight and spring from driven pulley.
Remove seal collar from driven pulley.
Remove guide pin, guide pin roller, and movable
driven face, and then remove O-ring & oil seal
seat from movable driven face.
Clutch nut wrench
Movable driven face
Clutch spring compressor
Seal
Collar
Guide pin
Inspection
Clutch outer
Measure the inner diameter of clutch outer.
Replace the clutch outer if exceed service limit.
Service limit: 130.5 mm
O-ring
Inner
diameter
Guide pin
Guide pin roller
Clutch outer
8-9
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Clutch lining
Measure each clutch weight thickness. Replace
it if exceeds service limit.
Service limit: 2.0 mm
Driven pulley spring
Measure the length of driven pulley spring.
Replace it if exceeds service limit.
Service limit: 83.2 mm
Clutch lining
Clutch weight
Driven pulley
Check following items:
y If both surfaces are damaged or worn.
y If guide pin groove is damaged or worn.
Replace damaged or worn components.
Measure the outer diameter of driven face and the
inner diameter of movable driven face. Replace it
if exceeds service limit.
Service limit: Outer diameter 33.94 mm
Inner diameter 34.06 mm
Driven Pulley Bearing Inspection
Check if the inner bearing oil seal is damage.
Replace it if necessary.
Check if needle bearing is damage or too big
clearance. Replace it if necessary.
Rotate the inside of inner bearing with fingers to
check if the bearing rotation is in smooth and silent.
Check if the bearing outer parts are closed and
fixed. Replace it if necessary.
Outer ball bearing
Free length
Driven face
Movable driven face
Guide pin groove
Needle bearing
8-10
To this chapter contents
8. V-BELT DRIVING SYSTEM/KICK STARTER
Clutch weight Replacement
Remove snap ring and washer, and then remove
clutch weight and spring from driving plate.
Caution
Some of models are equipped with one mounting
plate instead of 3 snap rings.
Check if spring is damage or insufficient elasticity.
Check if shock absorption rubber is damage or
deformation. Replace it if necessary.
Apply with grease onto setting pins.
Spring
Clutch weight
Shock absorption rubber
Driving plate
Snap ring
Setting pin
Install new clutch weight onto setting pin and then
push to the specified location.
Apply with grease onto setting pins.
But, the clutch block should not be greased. If so,
replace it.
Caution
Grease or lubricant will damage the clutch weight
and effect the block’s connection capacity.
Install the spring into groove with pliers.
Shock absorption rubber
Clutch weight
Spring
8-11
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