Suzuki EN125-2A Service Manual

SERVICE MANUAL

99500H06100-01E

EN125-2A

Prepared by

Customer Service Department

1st Ed. Aug, 2003

Part No.:99500H06100-01E

Printed in China

JIANG MEN DACHANGJIANG GROUP CO., LTD.

The SUZUKI EN125-2A was designed to offer superior performance through light weight
design and four stroke power. The new EN125-2A represents another major advance by
Suzuki in four stroke motorcycles.

This service manual has been produced primarily for experienced mechanics whose job is
to inspect, repair and service Suzuki Motorcycles. Apprentice mechanics and "do it
yourself " mechanics will also find this manual to be an extremely useful guide.

Model EN125-2A manufactured to standard specifications is the main subject matter of
this manual. However, the EN125-2A machines distributed in your country might differ in
minor respects from the standard-specification EN125-2A and, if they do, it is because
some minor modifications (which are of no consequence in most cases as far as servicing
is concerned) had to be made to comply with the statutory requirements of your country.

This manual contains up-to-date information at the time of its issue. Latermade
modifications and changes will be explained to each SUZUKI distributor in respective
markets, to whom you are requested to make query about updated information, if any.

FOREWORD

SUZUKI MOTOR CORPORATION

JIANG MEN DACHANGJIANG GROUP CO., LTD.

Customer Service Department

GROUP INDEX

1

GENERAL INFORMATION

2

3

4

5

6

7

PERIODIC MAINTENANCE AND
BREAK-IN PROCEDURES

ENGINE

FUEL AND LUBRICATION SYSTEM

ELECTRICAL SYSTEM

CHASSIS

SERVICING INFORMATION

GENERAL INFORMATION

CONTENTS

SERIAL NUMBER LOCATIONS

FUEL AND OIL RECOMMENDATIONS

BREAK-IN PROCEDURE

SPECIAL FEATURE

SPECIAL MATERIALS

SPECIFICATIONS

1-2

1-2

1-2

1-3

1-4

1-5

..............................

.......................

....................................

.........................................

......................................

..........................................

1

..............................

WARNING/CAUTION/NOTICE

1-1

1-1 GENERAL INFORMATION

WARNING/CAUTION/NOTE

Please read this manual and follow its instructions carefully. To emphasize special information, the symbol and the
words WARNING, CAUTION and NOTE have special meanings. Pay special attention to the messages highlighted
by these signal words.

WARNING:
Personal safety of the rider is involved, and disregard of the information could result in injury.

CAUTION:
For the protection of the motorcycle, the instruction or rule must be strictly adhered to.

NOTE:
Advice calculated to facilitate the repair of the motorcycle is given under this heading.

GENERAL PRECAUTION

Proper service and repair procedures are important for the safety of the service mechanic and the safety
and reliability of the motorcycle.
When more than 2 persons perform work in cooperation, pay attention to the safety of each other.
When it is necessary to run the engine indoors, make sure that exhaust gas is forced outdoors.
When working with toxic or flammable materials, make sure that area you work in is well-ventilated and that
you follow all of the material manufacturer s instrucations.
Never use gasoline as a cleaning solvent.
To avoid getting burned, do not touch the engine, engine oil, oil cooler and exhaust system until they have
cooled.
Afer servicing the fuel, oil, exhaust or brake systems, check all lines and fittings related to the system for
leaks.

WARNING:

If parts replacement is necessary, replace the parts with Suzuki Genuine Parts or their equivalent.
When removing parts that are to be reused, keep them arranged in an orderly manner so that they may be
reinstalled in the proper order and orientation.
Be sure to use special tools when instructed.
Make sure that all parts used in reassembly are clean. Lubricate them when specified.
Use the specified lubricant, bond or sealant.
When removing the battery, disconnect the negative cable first and then the positive cable.
When reconnecting the battery, connect the positive cable first and then the negative cable,and replace the
terminal cover on the positive terminal.
When performing service to electrical parts, if the service procedures not require use of batery power,
disconnect the negative cable the battery.
When tightening the cylinder head and case bolts and nuts, tighten the larger sizes first.
Always tighten the bolts and nuts diagonally from the inside working out and to the specified tightening
torque.
Whenever you remove oil seals, gaskets, packing, O-rings, locking washers, self-locking nuts, cotter pins,
circlips and certian other parts as specified, be sure to replace them with new ones. Also, before installing
these new parts, be sure to remove any left over material from the mating surfaces.
Never reuse a circlip. When installing a new circilp, take care not to expand the end gap larger than
required to slip the circlip over the shaft. After installing a circlip, always ensure that it is completely seated
in its groove and securely fitted.
Use a torque wrench to tighten fasteners to the specified torque. Wipe off grease and oil if a thread is
smeared with them.
After reassembling, check parts for tightness and proper operation.

CAUTION:

To protect the environment, do not unlawfully dispose of used motor oil, engine coolant and other
fluids: batteries tires.
To protect Earth's natural resources, properly of uesd motorcycle and parts.

Please note, however, that the warnings and cautions contained in this manual cannot possibly cover all potential
hazards relating to the servicing, or lack of servicing, of the motorcycle. In addition to the WARNINGS and
CAUTIONS stated, you must use good judgement and basic mechanical safety principles. If you are unsure about
how to perform a particular service operation, ask a more experienced mechanic for advice.

The frame serial number is stamped on the

steering head pipe. The engine serial number
is located on the crankcase.
These numbers are required especially for
registering the machine and ordering spare parts.

Ù

SERIAL NUMBER LOCATIONS

Use gasoline with an octane number of 90 97 or
higher (Research Method), preferably unleaded

-

FUEL AND OIL
RECOMMENDATIONS

FUEL

NOTE:
Unleaded and low-lead gasoline will extend
spark plug life.

ENGINE OIL

Be sure that the engine-oil you use comes under
API classification of SF or SG and that its
viscosity rating is SAE 10W-40. If SAE 10W-40
motor oil is not available, select the oil viscosity
according to the following chart:

FRONT FORK OIL

FORK OIL 10

During manufacture only the best possible materials
are used and all machined parts are finished to a
very high standard but it is still necessary to allow
the moving parts to "BREAK-IN" before subjecting
the engine to maximum stresses. The future
performance and reliability of the engine depends
on the care and restraint exercised during its
early life. The general rules are as follows:

BREAK-IN PROCEDURE

Keep to these break-in gine speed limits:en

Upon reaching an odometer reading of 1,600 km
you can subject the motorcycle to full throttle
operation.
However, do not exceed 10,000 r/min at any
time.
Do not maintain constant engine speed for an
extended time period during any portion of the
break-in. Try to vary the throttle position.

Initial 800 km

Up to 1,600 km

Over 1,600 km

Below 4,500 r/min

Below 5,500 r/min

Below 10,000 r/min

SAE

40

30
20W/50
10W/50
10W/30

20W
10W

-20 -10 0 10 20 30 40

-4 14 32 50 68 86 104

C

F

Temp.

2

1

Specification
and Classification

DOT3, DOT4

BRAKE FLUID

GENERAL INFORMATION 1-2

TRANSISTORIZED IGNITION SYSTEM WITH ELECTRONIC ADVANCE

DESCRIPTION

SPECIAL FEATURE

200

100

O

O

246810

Engine r/min (x 1000 r/min)

Fig.2

Closing angle (Degree)

1.0

0.5

246810

Engine r/min (x 1000 r/min)

Fig.3

Electric current (A)

On the Model EN125-2A, the timing advance characteristics of the ignition timing have been changed
from the previously-employed mechanical timing advance system incorporating a centrifugal advance
governor to an electronic timing advance system.

The ignitor has the following functions:
(1)Revolution advance angle control

Controls ignition timing in response to engine r/min.(See Fig.1,)

(2)Closing angle control

The introduction of this new electronic timing advance system minimizes fluctuations in the ignition
timing and also has improved the timing advance performance during high-speed operations.

When engine speed is low, reduces the conducting period (closing angle) of the transistor (Tr) so
that power consumption is reduced; when engine speed is high, increases the conducting period
(closing angle) to prevent voltage drop of the ignition coil. (See Figure 2 and 3.)

01234567891011

Engine r/min (x 1000 r/min)

Fig.1

Advance angle (Degree)

BTDC

13 BASE

O

0

20

10

30

19.0 2.8 /4500rpm

OO

16.9 3 /7000rpm

OO

Signal generator

Signal rolor

Pick-up coil

(A)

(B)

Ignitor unit

(Tr)

(C)

Ig

1

Ig

2

Ignition coil

Spark plug

Battery

Ignition switch

1-3 GENERAL INFORMATION

The materials listed below are needed for maintenance work on the EN125-2A and should be kept on hand
for ready use. These items supplement such standard materials as cleaning fluids, lubricants, emery cloth
and the like. How to use them and where to use them are described in the text of this manual.

SPECIAL MATERIALS

THREAD LOCK SUPER
"1303B"
99000-32030

THREAD LOCK CEMENT
99000-32040

THREAD LOCK "1342"
99000-32050

THREAD LOCK SUPER
"1305"
99000-32100

Cam sprocket bolts
2nd drive gear
Starter clutch allen bolt
Gear position sw. bolts

Front fork damper rod
bolts

Magneto rotor nut

Countershaft bearing
retainer screws
Gearshift cam guide
and pawl screws
Engine oil pump moun­ting screws
Pick up coil screws
Starter motor securing
screws

Material

SUZUKI
SUPER GREASE"A"
99000-25010

SUZUKI MOLY PASTE
99000-25140

SUZUKI BOND No.4
99000-31030

SUZUKI BOND No.1215
99000-31110

Part

Page

Oil seals

Wheel bearing

Brake cam

Steering stem

Dust seal cover and
spacer

Speedometer gear box

Wheel mounting drum

Brake piston holder

Piston pin
Valve stem
Camshaft journal
Rocker arm shaft

Front fork damper rod
bolt

Cylinder head cover

Mating surfaces of left
and right crankcase

Material Part

Page

3-24
3-25
3-28
3-28

3-47

5-3
5-31

5-32

5-36

2-2
5-3

5-31

5-22

5-10

2-4
3-29

3-27
3-44
3-53
3-55

5-10

3-44

3-48

3-49

6-2
6-11

3-53

5-16

3-47

GENERAL INFORMATION 1-4

1-5 GENERAL INFORMATION

SPECIFICATIONS

DIMENSIONS AND DRY MASS

ENGINE

TRANSMISSION

Overall length
Overall width
Overall height
Wheelbase
Ground clearance
Seat height
Dry mass

Type
Number of cylinders
Bore
Stroke
Piston displacement
Compression ratio
Carburetor
Air cleaner
Starter system
Lubrication system

Clutch
Transmission
Gearshift pattern
Primary reduction
Final reduction
Gear ratios, Low

2nd

Drive chain

3rd
4th
Top

..........................................

.............................

..........................................

........................................

.............................

..............................

....................................

....................................

.................................

..............................

........................................

..................................

...............................

...............................

.................................

................................

................................

................................

................................

................................

....................................

..................................

..................................

..................................

....................................

...............................

.....................................

......................................

Four-stroke, air-cooled, OHC
1

57.0mm

48.8mm
124cm

9.2:1
MIKUNI BS26SS, single
Polyurethane foam element

Wet sump

3

Electric

Wet multi-plate type
5-speed constant mesh
1-down, 4-up

3.470(59/17)

3.214(45/14)

3.000(33/11)

1.857(26/14)

1.368(26/19)

1.143(24/21)

0.957(22/23)
KMC 428H 118 Links

1945mm
735mm
1070mm
1265mm
160mm
750mm
122kg

GENERAL INFORMATION 1-6

ELECTRICAL

..................................

..................................

....................................

.......................................

.........................................

......................................

.................................

................................

.........................

............................

..............................

................................

..............................

.........................

..................................

.........................

Ignition type
lgnition timing

Spark plug
Battery
Fuse
Headlight
Tail/Brake light
Turn signal light
Turn signal indicator light
Neutral indicator light
Speedometer light
Tachometer light
Fuel capacity light
High beam indicator light
Position lamp
Gear position indicator

Transistorized
13 B.T.D.C. below 1 950 r/mim

NGK CR8E, NIPPON DENSO U24ESR-N
12V 28.8kc(7Ah) 10h
10A, 15A

12V 5W/21W
12V 21W
12V 2W 2
12V 2W
12V 3W
12V 3W
12V 3W
12V 2W
12V 5W
12V 2W

O

34.1 B.T.D.C. above 9 000 r/min

O

32 B.T.D.C. between 4 000-5 000 r/min

29.9 B.T.D.C. between 6 000-7500 r/min

O

O

12V 35W/35W

CHASSIS

...............................

................................

..................................

........................................

..........................................

..................................

....................................

....................................

..................................

..................................

Telescopic, coil spring, oil dampened
Swing arm, oil dampened
spring 5-way adjustable
42 (right and left)
64 30
90mm

2.1m
Disc
Internal expanding
80/100-18 4PR Tubeless
90/90-18

O

O

4PR Tubeless

Front suspension
Rear suspension

Steering angle
Caster
Trail
Turning radius
Front brake
Rear brake
Front tire size
Rear tire size

*The specifications subject to change without notice.

CAPACITIES

.......................

.......................

.....................................

...................................

Fuel tank including reserve

reserve
Engine oil
Front fork oil

14 L

2.0 L
1100 ml
139 ml

PERIODIC MAINTENANCE AND
TUNE-UP PROCEDURES

CONTENTS

PERIODIC MAINTENANCE SCHEDULE

MAINTENANCE PROCEDURES

BATTERY

CYLINDER HEAD NUTS, CYLINDER NUTS, EXHAUST PIPE

BOLTS AND NUTS

AIR CLEANER ELEMENT

VALVE CLEARANCE

COMPRESSION PRESSURE

SPARK PLUG

FUEL HOSE

FUEL FILTER

ENGINE OIL

ENGINE OIL FILTER

OIL PRESSURE

OIL SUMP FILTER

CARBURETOR

CLUTCH

DRIVE CHAIN

BRAKES

TIRES

STEERING

FRONT FORK OIL

CHASSIS AND ENGINE BOLTS AND NUTS

2-1

2-3

2-3

2-4

2-5

2-6

2-7

2-7

2-8

2-8

2-8

2-9

2-10

2-10

2-11

2-10

2-11

2-12

2-15

2-16

2-16

2-17

................

.........................

...............................................

.......................................

................................

....................................

.............................

...........................................

..............................................

............................................

.............................................

.....................................

.........................................

.......................................

.........................................

................................................

...........................................

................................................

...................................................

..............................................

.......................................

...............

2

2-1 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

PERIODIC MAINTENANCE SCHEDULE

The chart below lists the recommended intervals for all the required periodic service work necessary to
keep the motorcycle operating at peak performance and economy.

NOTE:
More frequent servicing may be performed on motorcycles that are used under extreme severe
conditions.

PERIODIC MAINTERNANCE CHART

ENGINE

Battery

Cylinder head nuts, cylinder nuts,

exhaust pipe bolts and nut

Air cleaner element

Valve clearance

Compression pressure

Spark plug

Fuel hose

Fuel filter

Engine oil

Engine oil filter

Oil pressure

Oil sump filter

Carburetor

Clutch

Interval

ltem

Inspect

Inspect

Inspect

Inspect

Inspect

Clean

Change

Replace

Inspect

Inspect

-

-

Inspect

Initial 1 000 km

Clean every 3 000 km

Inspect

Inspect

Inspect

Inspect

Inspect

Inspect

Change

Replace

Inspect

Inspect

Inspect

-

-

Every 4 000 km

Replace

Clean

Clean

-

-

-

-

-

-

-

-

-

-

Every 8 000 km

23

24

25

26

27

27

28

28

28

29

29

29

210

210

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page

Replace every 4 years

CHASSIS

Drive chain

Brakes

Brake hose

Brake fluid

Tires

Steering

Front fork oil

Chassis bolts and nuts

Inspect

Inspect

Inspect

Inspect

Change

Inspect

Inspect and clean every 1 000 km

211

212

212

212

215

216

216

217

-

-

-

-

-

-

-

-

Replace every 4 years

Change every 2 years

Inspect

Inspect

Inspect

Inspect

Inspect

-

Change

-

-

-

-

-

52040

Km

Months

Interval

ltem

Initial 1 000 km

Every 4 000 km Every 8 000 km

Page

52040

Km

Months

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-2

PERIODIC LUBRICATION CHART

The maintenance schedule, which follows, is based on this philosophy. It is timed by odometer indication,
and is calculated to achieve the ultimate goal of motorcycle maintenance in the most economical manner.

Throttle cable

Throttle grip

Clutch cable

Speedometer cable

Speedometer gear box

Tachometer cable

Drive chain

Brake pedal

Brake cam shaft

Steering stem bearings

Swing arm bearings

Interval

ltem

Engine oil

Engine oil

Grease or engine oil

-

-

-

-

-

Initial and Every 6 000 km Every 12 000 km

Engine oil every 1 000 km

Greaseevery2yearsor20000km

Grease

-

-

-

Grease

Grease

Grease

Grease

Lubricate exposed parts which are subject to rust, with either motor oil or grease whenever the motorcycle
has been operated under wet or rainy conditions.
Before lubricating each part, clean off any rusty spots and wipe off any grease, oil, dirt or grime.

WARNING:
Be careful not to apply too much grease to the brake cam shafts. If grease gets on the linings,
brake slippage will result.

6

12

Km

Months

2-3 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

This section describes the service procedures for
each section of Periodic Maintenance.

MAINTENANCE PROCEDURES

For checking specific gravity, use a hydrometer to
determine the charged condition.

BATTERY

Inspect initial 1 000 km and Every 4 000 km

The battery must be removed to check the
electrolyte level and specific gravity.
Remove the right frame cover.
Remove battery lead at the battery terminal.
Remove battery lead.
Remove battery from the frame.
Check electrolyte for level and specific gravity.
Add distilled water, as necessary, to keep the
surface of the electrolyte above the LOWER

LEVEL line but not above the UPPER LEVEL

line .

09900-28403

Hydrometer

Standard specific
gravity

1.28 at 20

O

C

An S.G. reading of 1.22 (at 20 C ) or under means
that the battery needs recharging off the machine:
take it off and charge it from a recharger.
Charging the battery in place can lead to failure of
the regulator/rectifier.

O

To install the battery, reverse the procedure
described above.

Make sure that the breather pipe is tightly
secured and undamaged, and is routed as
shown in the figure.

WARNING:
When installing the battery lead wires, fix the

lead first and lead last.

Breather pipe

Battery

1

2

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-4

Remove the seat and fuel tank
(Refer to page 3-2)
Remove the right and left caps of the cylinder
head cover after remove the tachometer cable
().
Remove the cylinder head cover
(Refer to page 3-8)

Tighten the four 10mm nuts and two 6-mm

nuts to the specified torque with a torque
wrench, when engine is cold.

.

Refer to page 3-5

.

CYLINDER HEAD NUTS, CYLINDER
NUTS, EXHAUST PIPE BOLTS AND
NUT

Inspect initial 1 000 km and Every 4 000 km

CYLINDER HEAD NUTS

When installing cylinder head cover, apply
SUZUKI BOND No.1215 to the mating surface
of cylinder head (Refer to page 3-29).

SUZUKI BOND No.1215

99000-31110

Tighten the two 6 mm nuts to the specified
torque.

CYLINDER NUTS

Tightening torque

711Nm-

-(0.7 1.1 kg m)

Tightening
torque

10 mm

25 N m

(2.5 .5 kg m)

-35

-3

6mm

711Nm

(0.7 1.1 kg m)

-

-

Tighten the exhaust pipe bolts and muffler

clamp bolt to the specified torque.

EXHAUST PIPE BOLTS AND MUFFLER
CLAMP BOLT

Tightening torque

Exhaust pipe
bolts and muffler
clamp bolt

912Nm

(0.9 1.2 kg m)

-

-

2

4

3

1

5

2-5 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

Fill a washing pan of a proper size with
nonflammable cleaning solvent. Immerse the
element in the cleaning solvent and wash it clean.
Squeeze the cleaning solvent out of the washed
element by pressing it between the palms of
both hands.
Immerse the element in motor oil, and squeeze
the oil out of the element leaving it slightly wet
with oil.

AIR CLEANER ELEMENT

Clean Every 3 000 km

If the air cleaner is clogged with dust, intake
resistance will be increased with a resultant
decrease in power output and an increase in fuel
consumption.
Check and clean the element in the following
manner.

Remove the left frame cover.
Remove the screws and take out the air cleaner
element assembly.
Separate the polyurethane foam element from
the element frame.

NOTE:
When installing the air cleaner case cover,
place the "UP" mark upward.

NOTE:
Do not twist or wring the element because it
will tear or the individual cells of the element
will be damaged.

CAUTION:
Inspect the element carefully for rips, torn
seams, etc. If any damage is noted, replace
the element.

Element

Non-flammable
Cleaning
Solvent

4

3

1

2

Motor oil

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-6

Excessive valve clearance results in valve noise
and insufficient valve clearance results in valve
damage and reduced power. At the distances
indicated above, check and adjust the clearance
to the following specification.

The procedure for adjusting the valve clearance
is as follows:

Remove the seat and fuel tank.
Remove the tachometer cable.
Remove the left cap of the cylinder head cover.

Remove spark plug, valve inspection caps ,

and valve timing inspection plug .

Remove the magneto cover cap and rotate
the magneto rotor with the 14 mm box wrench to
set the piston at (TDC) of the compression
stroke.
(Rotate the rotor until the "l line on the rotor is
aligned with the center of hole on the crankcase.)
Insert the thickness gauge to the valve stem
end and the adjusting screw on the rocker arm.

Remove the right cap of the cylinder head cover.

"

NOTE:
Valve clearance is be checked when the
engine is cold.
Both the intake and exhaust valves must be
checked and adjusted when the piston is at
Top-Dead-Center (TDC) of the compression
stroke.

VALVE CLEARANCE

Inspect initial 1 000 km and Every 4 000 km

Thickness gauge

09900-20803

Valve clearance specifications

IN.
EX.

0.04 0.07 mm

0.13 0.18 mm

-

-

If clearance is off the specification, bring it into
the specified range by using the special tool.

Tappet adjust driver

09917-13210

Reinstall spark plug, valve inspection caps,
cylinder hand cover caps, tachometer cable, valve
timing inspection plug and magneto cover cap.

1

1

2

3

2-7 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

Remove the carbon deposits with a wire or pin and
adjust the spark plug gap to 0.7-0.8 mm,
measuring with a thickness gauge.
When removing carbon deposits, be sure to
observe the appearance of the plug, noting the
color of the carbon deposits. The color observed
indicates whether the standard plug is suitable or
not. If the standard plug is apt to get wet, a hotter
plug should be used. If the standard plug is apt to
overheat (porcelain is whitish in appearance),
replace with a colder one.

NOTE:
"R" type spark plug fitted under some of
specifications and it means that the resistor
is located at the center electrode to prevent
radio noise.

COMPRESSION PRESSURE

Inspect initial 1 000 km Every 4 000 km

Refer to page 3-1.

SPARK PLUG

Inspect initial 1 000 km and Every 4 000 km
Replace Every 8 000 km

NGK CR7E
NIPPON DENSO U22ESR-N

Hot type

NGK CR8E
NIPPON DENSO U24ESR-N

Standard

NGK CR9E
NIPPON DENSO U27ESR-N

Cold type

0.7 mm-0.8 mm

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-8

Inspect the fuel hose and connections for damage
and fuel leakage.
If any defects are found, the fuel hose must be
replaced.

FUEL HOSE

Inspect initial 1 000 km and Every 4 000 km
Replace every four years.

If the fuel filter is dirty with sediment, fuel will not
flow smoothly and loss in engine power may result.
Clean the filter with non-flammable cleaning
solvent.

FUEL FILTER

Clean initial 1 000 km and Every 8 000 km

Support the motorcycle by center stand.

Drain the oil by removing the drain plug and

filler cap .

Fit the drain plug securely and add fresh oil
through the filler. The engine will hold about
1100 ml of oil.
Use 10W/40 viscosity of oil under API
classification of SF or SG.
Start up the engine and allow it to run for
several seconds at idling speed.
Shut down the engine and wait about one
minute. Then check the oil level in the oil level

window . The motorcycle must be in a level,
upright position for accurate measurement. If
the level is below the "L mark, add oil until the"

The oil should be changed with the engine hot.
The procedure is as follows:

ENGINE OIL

Change initial 1 000 km and Every 4 000 km

3

2

1

1

2-9 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

NOTE:
Pour about 1,150 ml of engine oil into the
engine only when changing oil and replacing
oil filter at the same time.
When performing engine overhaul, the
amount of oil to be replenished is 1,350 ml.

ENGINE OIL FILTER

Replace initial 1 000 km and Every 4 000 km

Drain engine oil by removing the drain plug.
Remove the three screws securing the filter cap.
Take off the cap, and pull out the filter.

Replace the oil filter in the following manner:

Replace the filter with a new one.
Before installing on the filter, check to be sure

that the O-ring is properly installed.
Before putting on the filter cap, check to be sure

that the filter spring and the O-ring are
installed correctly.
Replace the filter cap and tighten the screws
securely.
Pour in engine oil and check the level.

CAUTION:
When reassembling the oil filter, make sure
to check the oil filter installed as shown in
illustration. If the filter is installed improperly,
serious engine damage may result.

OIL PRESSURE

Inspect Every 4 000 km

Refer to page 3-1.

Clean the sump filter screen to remove any foreign
matter that may be collected there. Inspect the
screen to insure that it is free of any sign of damage.

OIL SUMP FILTER

Clean Every 8 000 km

1

3

2

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-10

Loosen the lock nut and screw the adjuster
on the clutch lever holder all the way in.

Loosen clutch cable adjuster lock nut .

Turn the clutch cable adjuster in or out to
acquire the specified play.
Tighten lock nut while holding the adjuster in

CARBURETOR

Inspect initial 1 000 km and Every 4 000 km

THROTTLE CABLE PLAY

There should be 0.5-1.0 mm play on the throttle
cable .To adjust the throttle cable play.

Clutch play should be 4 mm as measured at the
clutch lever holder before the clutch begins to
disengage. If the play in the clutch is incorrect,
adjust it in the following way:

CLUTCH

Inspect initial 1 000 km and Every 4 000 km

IDLING ADJUSTMENT

NOTE:
Make this adjustment when the engine is hot.

Start up the engine and set its speed at
anywhere between 1 300 and 1 500 r/min by

turning throttle stop screw .

Engine idle speed

1400 100r/min

A

Tug on the throttle cable to check the amount of
play.

Loosen the two lock nuts and turn the adjuster

in or out until the specified play is obtained.

Secure the lock nuts while holding the adjuster

0.5 1.0 mm-

The clutch cable should be lubricated with a light
weight oil whenever it is adjusted.

1

A

4

3

3

1

2

4mm

Throttle cable play

A

2

2-11 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

DRIVE CHAIN

Inspect and Clean Every 1 000 km

DRIVE CHAIN

Visually inspect the drive chain for the below listed
possible malconditions. (Lift the rear wheel by
placing the center stand, and turn the rear wheel
slowly by hand when the transmission in NEUTRAL.)
Inspect for:

Wash the chain with kerosene. If the chain
tends to rust faster, the interval must be
shortened.
After washing and drying the chain, lubricate it
with chain lube or gear oil SAE #90.

Check the drive chain for wear and adjust the
chain tension as follows:

Loosen axle nut after pulling out cotter pin

and loosen the lock nut .
Adjust the drive chain carefully by tightening

the adjuster .

Ù

Loosen the adjuster until the chain has 10 20
mm of sag at the middle between engine and
rear sprockets.

The mark on both chain adjusters must be at
the same position on the scale to ensure that
the front and rear wheels are correctly aligned.
After adjusting the drive chain, tighten the lock

nut and the axle nut securely and lock with

-

Ù

CHAIN SAG

Count out 21 pins on the chain and measure the
distance between. If the distance exceeds

259.4 mm, the chain must be replaced.

CHAIN WEAR

Service Limit

Drive chain
20 pitch length

259.4 mm

10-20mm

1 2 3 19 20 21

4

3

1

2

5

If any defects are found, the drive chain must be
replaced.

1. Loose pins

2. Damaged rollers

3. Rusted links

4. Twisted or seized links

5. Excessive wear

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-12

Support the motorcycle body on the center
stand, and place the handlebars straight.
Check the brake fluid level by observing the
lower limit line on the brake fluid reservoir.
When the level is below the lower limit line,
replenish with brake fluid that meets the
following specification.

FRONT BRAKE
Brake fluid level

Specification
and Classification

DOT3, DOT4

SUZUKI BRAKE FLUID

99000-23021

CAUTION:
The brake system of this motorcycle is filled
with a glycol-based brake fluid. Do not use
or mix different types of fluid such as
silicone-based and petroleum-based fluid
for refilling the system, otherwise serious
damage will be caused. Do not use any
brake fluid taken from old or used or
unsealed containers. Never re-use the brake
fluid left over from the last servicing and
stored for long periods.

WARNING:
Brake fluid, if it leaks, will interfere with safe
running and immediately discolor painted
surfaces.
Check the brake hose for cracks and hose
joint for leakage before riding.

Brake pads

Inspect wear situation of brake pads.
Replace the pads with new ones as necessary
(Refer to page 6-20).

UPPERUPPER

BRAKERS

Inspect initial 1 000 km and every 4 000 km
Replace brake hose every 4 years.
Change brake fluid every 2 years.

LOWERLOWER

2-13 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

Air bleeding the brake fluid circuit

Air trapped in the fluid circuit acts like a cushion to
absorb a large proportion of the pressure
developed by the master cylinder and thus
interferes with the full braking performance of the
caliper brake. The presence of air is indicated by
"sponginess" of the brake lever and also by lack of
braking force. Considering the danger to which
such trapped air exposes the machine and rider, it
is essential that, after remounting the brake and
restoring the brake system to the normal condition,
the brake fluid circuit be purged of air in the
following manner:

Fill up the master cylinder reservoir to the
"HIGH"level line .Replace the reservoir cap to
prevent entry of dirt.
Attach a pipe to the caliper bleeder valve, and
insert the free end of the pipe into a receptacle.

Squeeze and release the brake lever several
times in rapid succession, and squeeze the
lever fully without releasing it. Loosen the
bleeder valve by turning it a quarter of a turn so
that the brake fluid runs into the receptacle; this
will remove the tension of the brake lever
causing it to touch the handlebar grip. Then,
close the valve, pump and squeeze the lever,
and open the valve. Repeat this process until
the fluid flowing into the receptacle no longer
contains air bubbles.

Close the bleeder valve, and disconnect the pipe.
Fill the reservoir to the "HIGH" level line.

Bleeder valve
tightening torque

NOTE:
Replenish the brake fluid reservoir as
necessary while bleeding the brake system.
Make sure that there is always some fluid
visible in the reservoir.

CAUTION:
Handle the brake fluid with care: the fluid
reacts chemically with paint, plastics,
rubber materials, etc.

79Nm

0.7 0.9 kg m)

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-14

REAR BRAKE

Bring the brake pedal to a position about 10 mm
(behind the frame). This is effected by turning the

brake pedal stopper after remove the two
screws and take off the right cover. Be sure to
tighten the lock nut securely after setting the bolt.

Ù

10 mm

After adjusting the rear brake height, adjust the
brake pedal travel. First set the pedal at a position
for comfortable riding by turning the brake pedal

stopper , and then adjust the free travel to 20
30 mm.
If adjustment is necessary, turn the rear brake

adjuster to obtain the specific play.

Ù -

Brake pedal travel

20 30 mm-

Rear brake height

H

H

2

3

1

2-15 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

TIRES

Inspect initial 1 000 km and Every 4 000 km

TIRE

Inspect the tires for wear and damage; and check
the tire tread depth as shown. Replace a badly
worn or damaged tire. A tire with its tread worn
down to the limit (in terms of tread depth) must be
replaced.

Check the tire pressure, and examine the valve for
evidence of air leakage.

TIRE TREAD DEPTH SERVICE LIMIT

Front

1.6 mm

Rear

1.6 mm

TIRE PRESSURE

Normal riding

kPa kPa

kg/cm

2

kg/cm

2

Front

175 1.75 175 1.75

Rear

200 2.00 225 2.25

Cold inflation
tire pressure

Sold riding

Dual riding

Fist check if the brake system is properly
adjusted.
While operating the brake, check to see that the
extension line from the index mark is within the
range on the brake panel.
If the index mark is outside the range as shown
in the illustration at right, the brake shoe assy
should be replaced to ensure safe operation.

Brake lining wear limit

This motorcycle is equipped with brake lining wear
limit indicator on rear brake. As shown in the
illustration at right, at the condition of normal
lining wear, an extended line from the index mark
on the brake camshaft should be within the range
embossed on the brake panel with the brake on. To
check wear of the brake lining, follow the steps
below.

The extension line of the index mark is outside of the range.

The extension line of the index mark is within the range.

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-16

STEERING

Inspect initial 1 000 km and Every 4 000 km

Steering stem bearings be adjusted properly for
smooth turning of the handlebars and safe running.
Steering which is too stiff prevents smooth
movement of handlebars.
Steering which is too loose will cause vibration
and damage to the steering bearings. Check to
see that there is no play in the front fork attachment.

If the play is found, perform steering bearing
adjustment as described in page 6-16 of this manual.

Tightening torque

ITEM

Handlebars clamp bolts

Steering stem head bolts

Front fork upper
clamp bolt

Front fork lower
clamp bolt

12 20- 1.2 2.0-

35 55- 3.5 5.5-

20 30- 2.0 3.0-

25 35- 2.5 3.5-

A

B

C

D

FRONT FORK OIL

Change Every 8 000 km

Remove the front fork (See page 6-4)
Let out the fork oil (See page 6-8)
Pour specified amount of oil from the top of the
inner tube.

.

.

Specified amount

(each tube)

139 ml

Fork oil #10

Specification

Tightening torque

ITEM

Fork top cap

Front fork upper clamp bolt

Front fork lower clamp bolt

15 30- 1.5 3.0-

20 30- 2.0 3.0-

25 35- 2.5 3.5-

C

C

B

D

A

2-17 PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES

CHASSIS AND ENGINE MOUNTING BOLTS AND NUTS

Inspect initial 1 000 km and Every 4 000 km

The nuts and bolts listed are important parts, and they must be in good condition for safety.
They must be retightened, as necessary, to the specified torque with a torque wrench.

Tightening torque

ITEM

Front axle nut

Caliper mounting bolt

Brake hose union bolt

Master cylinder bolt

Swing arm pivot nut

Rear shock absorber fitting nut

Rear axle nut

Rear torque link bolt

Rear brake cam lever bolt

3.6 5.2

2.5 4.0

2.5 3.5

0.5 0.8

5.0 8.0

2.0 3.0

5.0 8.0

1.0 1.5

0.5 0.8

3.7 4.5

-

-

-

-

-

-

-

-

-

-

2.8 3.4-

Engine mounting bolt

36 52

25 40

25 35

58

50 80

20 30

50 80

10 15

58

37 45

-

-

-

-

-

-

-

-

-

-

28 34-

B B

A A

3

1

3

2

4

5

PERIODIC MAINTENANCE AND TUNE-UP PROCEDURES 2-18

7

6

6

8

9

B

B

A

ENGINE

CONTENTS

3-1

3-2

3-7

3-12

3-23

3-30

3-38

3-42

...........

.....................

.................

............................................

.................

................

............................................

.................

3

COMPRESSION PRESSURE AND OIL PRESSURE

ENGINE REMOVAL AND REMOUNTING

UPPER END COMPONENTS DISASSEMBLY

UPPER END COMPONENTS INSPECTION

AND SERVICING

UPPER END COMPONENTS REASSEMBLY

LOWER END COMPONENTS DISASSEMBLY

LOWER END COMPONENTS INSPECTION

AND SERVICING

LOWER END COMPONENTS REASSEMBLY

3-1 ENGINE

COMPRESSION PRESSURE AND OIL PRESSURE

COMPRESSION PRESSURE

Remove spark plug.

Fit the compression gauge and adapter to
the plug hole, taking care to make the connection
absolutely tight.
Twist the throttle grip into wide-open position.
Crank the engine several times with the starter
motor, and read the highest gauge indication as
the compression of the cylinder.

Ù

A low compression pressure may indicate any of
the following malfunctions:

Excessively worn cylinder wall.
Worn piston or piston rings.
Piston rings stuck in the grooves.
Poor seating contact of valves.
Defective cylinder head gasket.

NOTE:

Before testing the engine for compression
pressure, make sure that the cylinder head
nuts and bolts are tightened to specified
torque values and valves are properly
adjusted.
Have the engine warmed up by idling
before testing it.

*

*

Compression gauge

09915-64510

Adapter

09915-63310

Ù

Compression pressure

Standard

Limit

8kg/cm

2

10 14 kg/cm-

2

When the compression pressure noted is down to
or below the limit indicated above, the engine
must be disassembled, inspected and repaired as
required.

OIL PRESSURE

Install the oil pressure gauge in the position
shown in the illustration.
Warm up the engine as follows.
Summer approx. 10 min. at 2 000 r/min.
Winter approx. 20 min. at 2 000 r/min.
After the warming up operation, increase the
engine speed to 3 000 r/min, and read the oil
pressure gauge

Oil pressure

Above 0.1 kg/cm

Below 0.3 kg/cm at 3 000 r/min.

2

2

Oil pressure gauge

09915-74510

If the pressure is too low, it means that the oil
pump is internally worn or otherwise defective
and the complete oil pump unit needs to be
replaced.

3

1

2

1

2

3

Before taking the engine out of the frame,
thoroughly clean the engine with a suitable
cleaner.
The procedure of engine removal is sequentially
explained in the following steps.

Take off the right and left frame covers.
Disconnect the and lead wires of battery.

ENGINE 3-2

ENGING REMOVAL AND REMOUNTING

ENGING REMOVAL

CAUTION:
First, disconnect the lead wire.

Turn the fuel cock lever "OFF" position.
Take off the fuel hose.

Remove the seat by using the key.

Take off the fuel tank by removing the mounting
bolts and discounnect the coupler of fuel
capacity sensor.

3-3 ENGINE

Take off the clutch cable by removing the clutch
lever bolt and adjuster lock nut.
Take off the breather pipe.

Loosen the throttle cable adj ster lock nuts,
and take off the throttle cable.

u

Remove the carburetor by unscrewing the
clamp screws.

Disconnect the couplers of generator and gear
position indicator.

ENGINE 3-4

Remove gear shift lever.
Take off the engine sprocket cover.

Disconnect the lead wire of starter motor.
Take off the spark plug cap.

Take off the drive chain by removing the clip.

Disconnect the ground wire from the crankcase.

Direction of travel

3-5 ENGINE

Remove the tachometer cable.
Take off the left and right caps of the cylinder
head cover.

Remove the exhaust pipe nuts and muffler
mounting bolt, then take off the muffler.

Remove engine mounting bolts, swing arm pivot
nut, footrest bar bolts and brackets.
Use both hands, and lift the engine from the
frame.

NOTE:
The engine must be taken out from the right
side.

CAUTION:
Be careful not to draw out the swing arm
pivot shaft completely from the left side
swing arm pivot hole. Insert the shaft or rod
into the right side pivot hole from the right
side of the frame to keep the alignment of the
frame holes and swing arm pivot holes.

The engine can be mounted in the reverse order of
removal.

Temporarily fasten the engine mounting bracket
before inserting the engine mounting bolts.

ENGINE 3-6

ENGINE REMOUNTING

NOTE:
The engine mounting nuts are self-lock nuts.
Once the nut has been removed, it is no
longer of any use. Be sure to use new nuts
and tighten them to the specified torque.

Tightening torque for engine mounting bolts

L: (80 mm)

37 45 N m

(3.7 4.5 kg m)

-

-

The Others

28 34 N m

(2.8 3.4 kg m)

-

-

Tightening the exhaust pipe nuts and muffler
mounting bolt to specified torque.

Exhaust
pipe bolts

912Nm

(0.9 1.2 kg m)

-

-

Pour 1.35 L of engine oil SAE10W/40 graded SF
or SG into the engine after overhauling engine.
Start up the engine and allow it run for several
seconds at idle speed. About one minute after
stopping engine, check oil level.
If the level is below the "L mark, add oil with the
level reaches the""F" mark.

Align the release arm slit surface with the notch
mark on the release cam shaft.

Installing position for clutch release arm

After remounting the engine, following adjust­ments are necessary.

Throttle cable play
Clutch cable
Drive chain
Idling speed

(Page: 2 )

(Page: 2 10)

(Page: 2 11)

(Page: 2 10)

-10

-

-

-

*
*
*
*

M8L50

M8L80

M8L88

M8

2.8-3.4kg.m

M8

3.7-4.5kg.m

M8

2.8-3.4kg.m

Notch Mark

Slit

3-7 ENGINE

UPPER END COMPONENTS DISASSEMBLY

CYLINDER HEAD COVER
AND CYLINDER HEAD

Drain engine oil.

NOTE:

If top end repair only is being performed,
it is not necessary to remove the engine
from the frame.
As already noted, seat, fuel tank, frame
covers etc. must be removed.

*

*

Remove magneto cover cap and inspection
plug.

Remove cam chain tensioner.

Remove valve inspection caps and spark plug.

ENGINE 3-8

Bring the piston to top dead center.

First, remove the tachometer sleeve securing
screw, and then pull out the tachometer driven
gear shaft with sleeve.
Next, loosen the cylinder head cover bolts in the
order indicated in the illustration and remove

Detach the cylinder head cover.

bracket comps of cylinder head cap.

NOTE:
When removing cylinder head cover, do not
remove conically recessed top bolts.

Detach the camshaft end cap.
Flatten camshaft sprocket lock washer.
Remove camshaft sprocket bolts and detach
the camshaft.

NOTE:

The cam chain tensioner bolt is to be
removed only when disassembling the engine.

Ù

CAUTION:
Do not drop camshaft drive chain, pin and
sprocket into crankcase.

1

Do not
remove

3

5

7

2

6

9

10

4

8

1

NOTE:
When removing cylinder head cover, piston
must be at top dead center on compression
stroke.

Loosen the six cylinder head nuts diagonally,
then detach the cylinder head.

NOTE:
If it is difficult to remove the cylinder head,
gently pry it off while tapping the finless
portion of the cylinder head with a plastic
hammer. Be careful not to break the fins.

3-9 ENGINE

Remove rocker arm shaft set bolts.

Pull out the rocker arm shafts with pliers.

Remove cylinder base nuts and cylinder.

CAUTION:
If tapping with plastic hammer is necessary.
do not break the fins.

ENGINE 3-10

Compress the valve spring by using the special
tool.

Valve lifter

09916-14510

Take off the valve cotters from valve stem.

Tweezers

09916-84510

Take out the valve spring retainer, inner spring
and outer spring.
Pull out the valve from the other side.

Remove oil seal, using long-nose pliers.
Take out the spring seat.

CAUTION:
Removed oil seal should be replaced with a
new one.

3-11 ENGINE

Remove valve guide by using the special tool.

Valve guide remover

09916-44910

CAUTION:
Only oversize valve guide is available as a
spare part.

Place a clean rag over the cylinder base to
prevent piston pin circlip from dropping into
crankcase and then, remove the piston pin
circlip with long-nose pliers.

Remove piston pin.

Piston pin puller

09910-34510

ENGINE 3-12

UPPER END COMPONENTS INSPECTION AND SERVICING

After removing sealant (SUZUKI BOND No.1215)
from the fitting surface of the cylinder head cover,
place the cylinder head cover on a surface plate
and check for distortion with a thickness gauge.
Check points are shown in Fig.

Service limit

0.05 mm

If the distortion exceeds the limit, replace the
cylinder head cover and cylinder head.

ROCKER ARM SHAFT O.D.

Standard

11.966 11.984 mm

Measure diameter of rocker arm shaft.

ROCKER ARM I.D.

Standard

12.000 12.018 mm

When checking the valve rocker arm, the inside
diameter of the valve rocker arm and wear of the
camshaft contacting surface should be checked.

CAMSHAFT

The camshaft should be checked for runout and
also for wear of cams and journals if the engine
has been noted to produce abnormal noise or
vibration or a lack of output power. Any of these
malconditions could be caused by a worn
camshaft.

CYLINDER HEAD COVER
DISTORTION

Micrometer
(0 25 mm)

09900-20205

3-13 ENGINE

CAMSHAFT CAM WEAR

Worn-down cams are often the cause of mistimed
valve operation resulting in reduced output power.
The limit of cam wear is specified for both intake
and exhaust cams in terms of cam height ,
which is to be measured with a micrometer.
Replace camshafts if found it worn down to the
limit.

Micrometer

(25 50 mm)

09900-20202

H

Cam height

service limit

Intake cam

33.350 mm

Exhaust cam

33.000 mm

Height

H

Measure the outside diameter of camshaft journal.
Replace either the cylinder head set or the cam
shaftiftheO.D.isincorrect.

Micrometer

(0 25 mm)

09900-20205

Camshaft journal
O.D.standard

21.959 21.980 mm

CAMSHAFT RUNOUT

Measure the runout with a dial gauge. Replace the
camshaft if the runout exceeds the limit.

09900-20701

09900-20606

09900-21304

Magnetic stand

Dial gauge (1/100 mm)

V-block (100 mm)

Service limit

0.10 mm

CAMSHAFT JOURNAL WEAR

ENGINE 3-14

NOTE:
Visually inspect each valve for wear of its
seating face. Replace any valve with an
abnormally worn face.

CYLINDER HEAD DISTORTION

Decarbon combustion chamber.
Check the gasketed surface of the cylinder head
for distortion with a straightedge and thickness
gauge, taking a clearance reading at several
places as indicated. If the largest reading at any
position of the straightedge exceeds the limit,
replace the cylinder head.

Service limit

0.05 mm

VALVE FACE WEAR

Measure the thickness and, if the thickness is
found to have been reduced to the limit, replace
the valve.

T

Service limit

0.5 mm

Support the valve with "V" blocks, as shown, and
check its runout with a dial gauge. The valve must
be replaced if the runout exceeds the limit.

VALVE STEM RUNOUT

Magnetic stand

Dial gauge (1/100 mm)

V-block (100 mm)

09900-20701

09900-20606

09900-21304

Service limit

0.05 mm

Place the dial gauge at right angles to the valve
head, and measure the valve head radial runout. If
it measures more than limit, replace the valve.

VALVE HEAD RADIAL RUNOUT

Service limit

0.03 mm

3-15 ENGINE

Re-finish the valve guide holes in cylinder head
with a 10.8 mm reamer and handle.

CAUTION:

This remedy is permissible where the
length will not be reduced to less than 2
mm. If this length becomes shorter than 2
mm, then the valve must be replaced.
After installing the valve whose stem end
has been ground off as above, check that
the face of valve stem end is above the
cotter .

*

*

If the valve stem is worn down to the limit, when
measured with a micrometer, replace the valve.

VALVE ST EM WEAR

Micrometer

(0 25 mm )

09900-20205

ValvestemO.D.

Standard

IN.

EX.

4.975-4.990 mm

4.955-4.970 mm

Inspect valve stem end face for pitting and wear.

VALVE GUIDE INSTALLATION

10.8 mm reamer 09916-34580

Handle

09916-34542

Fit a ring to each valve guide. Be sure to use
new rings and valve guides. Use of rings and
valve guides removed in disassembly must be
avoided.

ENGINE 3-16

5.0 mm reamer 09916-34570

Reamer Handle

09916-34542

After fitting all valve guides, re-finish their
guiding bores with a 5.0 mm reamer. Be sure to
clean and oil the guides after reaming.

Install valve spring lower seat . Be careful not
to confuse the lower seat with the spring
retainer .

Lubricate valve stem seal with oil, and press-fit
the seal into position with a finger tip.

CAUTION:
Do not reuse the oil seals.

Oil the stem hole, in each valve guide and drive
the guide into the guide hole using the valve
guide installer.

Valve guide installer

09916-44310

3-17 ENGINE

VALVE SEAT WIDTH

Coat the valve seat with prussian blue uniformly.
Fit the valve and tap the coated seat with the
valve face in a rotating manner, in order to
obtain a clear impression of the seating contact.
In this operation, use the valve lapper to hold
the valve head.

The ring-like dye impression left on the valve
face must be continuous without any break. In
addition, the width of the dye ring, which is the
visualized seat "width", must be within the
specification.

Valve seat width

0.9 1.1 mm

STD.

W

If either requirement is not met, correct the seat by
servicing it as follows.

VALVE SEAT SERVICING

NOTE:
The valve seat contact area must be inspected
after each cut.

INTAKE

EXHAUST

60

O

30

O

45

O

Valve seat

The valve seats for both intake and exhaust valves
are machined to four different angles. (The seat
contact surface is cut 45 ).

O

45

30

60

O

O

O

45

15

O

O

INTAKE SINDE

N-122 or N-116

N-126

N-111

EXHAUST SINDE

N-122 or N-116

N-121 or N-120

15

O

Valve seat

45

O

Vale seat cutter (N-121)

Vale seat cutter (N-122)

Vale seat cutter (N-126)

Solid pilot (N-100-5.0)

Vale seat cutter set

09916-20610

09916-20620

09916-20630

09916-24311

09916-21110

ENGINE 3-18

CAUTION:
Cut the minimum amount necessary from the
seat to prevent the possibility of the valve
stem becoming too close to the rocker arm
for correct valve contact angle.

After the desired seat position and width is
achieved, use the 45 cutter very lightly to clean
up any burrs caused by the previous cutting
operations.

O

Clean and assemble the head and valve
components. Fill the intake and exhaust ports
with gasoline to check for leaks. If any leaks
occur, inspect the valve seat and face for burrs
or other things that could prevent the valve from
sealing.

4.

5.

If the contact area is too high or too wide, use the
15 cutter (for exhaust side) and 30 /60 cutters
(for intake side) to lower and narrow the contact
area.

O OO

If the contact area is too low or too narrow, use the
45 cutter to raise and widen the contact area.

O

WARNING:
Always use extreme caution when handling
gasoline.

NOTE:
Be sure to adjust the valve clearance after
reassembling the engine.

Insert with a slight rotation, the solid pilot that
gives a snug fit. The shoulder on the pilot
should be about 10 mm from the valve guide.
Using the 45 cutter, descale and cleanup the
seat with one or two turns.
Inspect the seat by the previous seat width
measurement procedure. If the seat is pitted or
burned, additional seat conditioning with the
45 cutter is required.

O

O

1.

2.

3.

CAUTION:
DO NOT use lapping compound after the
final cut is made. The finished valve seat
should have a velvety smooth finish and not
a highly polished or shiny finish. This will
provide a soft surface for the final seating of
the valve which will occur during the first few
seconds of engine operation.

3-19 ENGINE

VALVE SPRINGS

Check the springs for strength by measuring their
free lengths and also the force required to
compress them. If the limit indicated below is
exceeded by the free length reading or if the
measured force does not fall within the range
specified, replace with a new spring as a set .

Valve spring tension

Valve spring free length

Service limit

Spring

INNER

31.2 mm

OUTER

33.6 mm

Standard

Spring

INNER

OUTER

3.77 4.43 kg/26.78 mm

8.86 10.4 kg/29.78 mm

CYLINDER DISTORTION

Check the gasketed surface of the cylinder for
distortion with a straightedge and thickness gauge,
taking a clearance reading at several places as
indicated. If the largest reading at any position of
the straightedge exceeds the limit, replace the
cylinder.

Service limit

0.05 mm

CYLINDER BORE

Measure the cylinder bore diameter at six places.
If any one of the measurements exceeds the limit,
replace the cylinder.

Cylinder gauge set

09900-20508

Service limit

57.085 mm

3.77-4.43 kg

26.78 mm

ENGINE 3-20

PISTON DIAMETER

Using a micrometer, measure the piston outside
diameter at the place 10 mm from the skirt end as
shown in Fig. If the measurement is less than the
limit, replace the piston.

Piston ring-groove clearance

Micrometer

(50 75 mm)

09900-20203

Service limit

56.880 mm

NOTE:
Using a soft-metal scraper, decarbon the
crown of the piston. Clean the ring grooves
similarly.

PISTON-CYLINDER CLEARANCE

As a result of the above measurement, if the
piston to cylinder clearance exceeds the limit
shown in the table below, rep ace both the cylinder
a d piston.

l

n

Service limit

0.120 mm

PISTON RING-GROOVE CLEARANCE

Using a thickness gauge, measure the side
clearance of the 1st and 2nd rings. If any of the
clearances exceeds the limit, replace both piston
and piston rings.

Thickness gauge

09900-20830

Piston ring

Service limit

1st

0.180 mm

2nd

0.150 mm

3-21 ENGINE

Before installing piston rings, measure the free
end gap of each ring using vernier calipers.
Next, fit the ring in the cylinder, and measure each
ring end gap using a thickness gauge.
If any ring has an excess end gap, replace the ring.

Thickness gauge

09900-20803

Piston ring

Service limit

1st

2nd

Piston ring groove width

Oil

1.01 1.03 mm

1.01 1.03 mm

2.01 2.03 mm

PISTON RING FREE END GAP AND
PISTON RING END GAP

Piston ring free end gap

Piston ring

Service limit

1st

2nd

5.6 mm

4.8 mm

R

R

Vernier calipers

09900-20101

Piston ring end gap

Piston ring

Service limit

1st and 2nd

0.50 mm

Piston ring

Service limit

1st

2nd

Piston ring thickness

0.97-0.99 mm

0.97-0.99 mm

ENGINE 3-22

PISTON PIN AND PIN BORE

Using a caliper gauge, measure the piston pin
bore inside diameter, and using a micrometer
measure the piston pin outside diameter. If the
difference between these two measurements is
more than the limits, replace both piston and
piston pin.

Micrometer

(0 25 mm)

09900-20205

Piston pin bore

Service limit

14.030 mm

Piston pin O.D.

Service limit

13.980 mm

CONROD SMALL END I.D.

Using a caliper gauge, measure the conrod small
end inside diameter.

Service limit

14.040 mm

If the conrod small end bore inside diameter
exceeds the limit, replace conrod.

3-23 ENGINE

TOP RING AND 2ND RING

Install spacer into the bottom ring groove first.
Then install both side rails , one on each side of
the spacer. The spacer and side rails do not have a
specific top or bottom when they are new. When
reassembling used parts. Install them in their
original place and direction.

UPPER END COMPONENTS REASSEMBLY

OIL RING

Top ring and 2nd ring differ in the shape of ring
face and the face of top ring is chrome-plated
whereas that of 2nd ring is not. The color of 2nd
ring appears darker than that of the top one.

Top and 2nd rings have the letter R" marked on
the top. Be sure to bring the marked side to the top
when fitting them to the piston.

"

Position the gaps of the three rings as shown.
Before inserting piston into the cylinder, check
that the gaps are so located.

ENGINE 3-24

The following are reminders for piston installation:

PISTON

Rub a small quantity of SUZUKI MOLY PASTE
onto the piston pin.
Place a clean rag over the cylinder base to
prevent piston pin circlip from dropping into
crankcase, and then fit the piston pin circlip with
long-nose pliers.

CAUTION:
Use a new piston pin circlip to prevent circlip
failure which will occur with a bent one.

When fitting the piston, turn hole on the piston
head to exhaust side.

Before mounting the cylinder, oil the big end and
small end of the conrod and also the sliding
surface of the piston.

CYLINDER

Fit dowel pins to crankcase and then fit gasket.

CAUTION:
To prevent oil leakage, do not use the old
gasket again, always use new one.

Hold each piston ring with the piston rings
properly spaced and insert them into the cylinder.
Check to insure that the piston rings are
properly inserted into the cylinder.

NOTE:
When mounting the cylinder, after attaching
camshaft drive chain , keep the camshaft
drive chain taut. The camshaft drive chain
must not be caught between cam drive chain
sprocket and crankcase when crankshaft is
rotated.

NOTE:
There is a holder for the bottom end of the
cam chain guide cast in the crankcase. Be
sure that the guide is inserted properly or
binding of the cam chain and guide may
result.

SUZUKI MOLY PASTE

99000-25140

3-25 ENGINE

VALVE AND SPRING

Insert the valves, with their stems coated with
SUZUKI MOLY PASTE all around and along the
full stem length without any break.
Similarly oil the lip of the stem seal.

Install valve springs, making sure that the
close-pitch end of each spring goes in first to
rest on the head. The coil pitch of both the inner
and outer springs vary: the pitch decreases
from top to bottom, as shown in the illustration.

CAUTION:
When inserting each valve, take care not to
damage the lip of the stem seal.

Fit valve spring retainer, compress spring with a
valve lifter and insert cotters.

SUZUKI MOLY PASTE

99000-25140

ENGINE 3-26

CYLINDER HEAD

Fit dowel pins to cylinder head and then,
attach new gasket to cylinder head.

Copper washers and cap nuts are used to
secure the cylinder head.

CAUTION:
Use a new cylinder head gasket to prevent oil
leakage. Do not use the old gasket.

With the head snugly seated on the cylinder,
secure it by tightening the nuts diagonally.
Tighten each nut to the torque value specified
below:

Cylinder head nuts tightening torque

8 mm Diam

6 mm Diam

711N m

(0.7 1.1 kg m)

25 N m

(2.5 .5 kg m)

After tightening the cylinder head nuts to the
specified torque, tighten the cylinder base nuts

to the specified torque.

Cylinder base
nuts tightening
torque

711N m

(0.7 1.1 kg m)

3-27 ENGINE

CAMSHAFT

Align the mark on magneto rotor with the index
mark on the crankcase keeping the camshaft
drive chain pulled upward.

CAUTION:
If crankshaft is turned without drawing the
camshaft drive chain upward. the chain will
be caught between crankcase and cam chain
drive sprocket.

Align the marks on the camshaft so it is parallel
with the surface of the cylinder head.
Fit lock washer so that it is covering the locating
pin.
Apply THREAD LOCK SUPER "1303B" to the
bolts and tighten the cam sprocket.

NOTE:
Apply grease on the cam sprocket locating
pin and install the pin into the camshaft.

Engage the chain on the cam sprocket with the
locating pin hole at just past top position.

NOTE:
Do not rotate magneto rotor while doing this.
When the sprocket is not positioned
correctly, turn the sprocket. When installing
the camshaft into the cam sprocket, pay
attention not to dislodge the locating pin or it
may fall into the crankcase.

Tightening torque

10 13 N m

(1.0 1.3 kg m)

THREAD LOCK SUPER
"1303B"

99000-32030

ENGINE 3-28

Bend up he washer tongue positively to lock the
bolts.

Apply SUZUKI MOLY PASTE to the camshaft
journal and place camshaft on cylinder head.

SUZUKI MOLY PASTE

99000-25140

VALVE ROCKER ARM AND SHAFT

Apply SUZUKI MOLY PASTE to the rocker arms
and shafts.
Place the spring and the wave washer and arm
in the exhaust side.
Place the wave washer and arm in the inlet side.
After inserting the shafts, tighten the set bolts.

CAUTION:

Use a new O-ring on the rocker arm shafts
to prevent oil leakage.
Use a new gasket on the set bolts to
prevent oil leakage.

*

*

99000-25140

SUZUKI MOLY PASTE

3-29 ENGINE

CYLINDER HEAD COVER

Thoroughly wipe off oil from the fitting surfaces
of cylinder head.
Fit the two dowel pins to the cylinder head side.
Uniformly apply SUZUKI BOND No.1215 to the
cylinder head surface.

SUZUKI BOND
No.1215

99000-31110

NOTE:
Do not apply SUZUKI BOND No.1215 to the
camshaft end cap.

Fit a gasket to head cover bolt correctly as
shown in Fig.

CAUTION:
Use only new gasket. To prevent oil leakage.

NOTE:
When tightening the cylinder head cover
bolts, position must be at top dead center on
compression stroke.

Lightly tighten the cylinder head cover bolts
diagonally and then, if everything is satisfactory,
tighten securely with a torque wrench to the
specified torque.

Tightening
torque

910N m

(0.9 1.0 kg m)

Apply engine oil to the tachometer driven gear
shaft and then, insert together with sleeve and
tighten the set screw.

Dowel PinDowel Pin

CAM DRIVE CHAIN TENSIONER

Install cam drive chain tensioner following the
procedure below.

VALVE CLEARANCE

Remove the lock bolt , and spring .
Fully insert push rod into the chain tensioner
by lift the pawl.
Mount the chain tensioner on the cylinder.
Install and tighten the lock nut and spring into
the chain tension.

After tightening the head cover bolts, check and
adjust the valve clearance. Refer to page 2-6
for procedures.

ENGINE 3-30

LOWER END COMPONENTS DISASSEMBLY

MAGNETO ROTOR

Remove magneto cover bolts and detach
magneto cover.

Loosen and remove the starter motor mounting
bolts.
Take off the starter motor.

Remove the starter idle gear.

Remove magneto rotor nut.

Rotor holder

09930-44511

NOTE:
Do not allow camshaft drive chain to be
caught between crankcase and camshaft
drive sprocket.

3-31 ENGINE

Remove magneto rotor and key.

Rotor remover
attachment

09930-30180

Slide shaft

09930-30102

Remove starter clutch gear.

Remove cam drive chain.

Remove roller , spring and push piece
from starter clutch.

Clamp the rotor with a vise taking care not to
damage it and remove the three allen bolts
using th 5 mm "T" type hexagon wrench.

"T" type hexagon
wrench (5 mm)

019911-73730

ENGINE 3-32

CLUTCH

Remove clutch cover bolts and oil filter cap
bolts, and detach clutch cover by tapping with a
plastic hammer.

Remove clutch spring mounting bolts
diagonally while holding the primary driven gear,
and remove clutch pressure plate.

Conrod holder

09910-20116

After removal of clutch drive and driven plates,
flatten the lock washer and remove the clutch
sleeve hub nut by using the special tool.

Clutch sleeve hub
holder

09920-53710

Take off the sleeve hub with the primary driven
gear assy.

3-33 ENGINE

Flatten the lock washer, then remove the nut,
lock washer and oil pump drive gear.

CAUTION:
This is a left-hand thread nut.

Remove oil pump driven gear, then remove
primary drive gear and key.

OIL PUMP

Remove oil pump mounting screws and take off
oil pump body.

NOTE:
When removing cam driven gear, do not lose
gear shifting pawl , pin and spring .

OIL PUMP DRIVE GEAR, DRIVEN GEAR
AND PRIMARY DRIVE GEAR

Conrod holder

09910-20116

GEAR SHIFTER

To remove cam driven gear, first remove gear
shifting shaft, and loosen pawl lifter and cam
guide screws with a impact driver.

ENGINE 3-34

DRIVE SHAFT RETAINER

Remove the drive shaft retainer circlip by using
snap ring pliers.

Snap ring pliers

09900-06107

NOTE:
When removing gear position switch, do not
lose contact and spring.

Remove gear position switch.

GEAR POSITION SWITCH

ENGINE SPROCKET

Flatten the lock washer, then remove the
sprocket nut by using the special tool.

Rotor and
sprocket holder

09930-40113

CRANKCASE

Remove sump filter cap and neutral cam
stopper.

3-35 ENGINE

Remove sump filter.

Remove crankcase securing bolts.

CAUTION:
The crankshaft and transmission
components must remain in the left
crankcase half. This is necessary because
the gear shifting cam stopper is mounted on
the left crankcase half and will be damaged if
the transmission components remain in the
right half.

Crankcase
separating tool

09920-13120

Separate the crankcase into 2 parts, right and
left with crankcase separating tool.

Fit the crankcase separating tool, so that the
tool plate is parallel with the end face of the
crankcase.

ENGINE 3-36

TRANSMISSION

Remove gear shifting cam stopper spring.

Draw out gear shifting fork shafts and take off
forks.

Remove clusters of gears and gear shifting cam.

CRANKSHAFT

Remove crankshaft by using crankshaft rem ver.o

Crankshaft remover

09920-13120

3-37 ENGINE

OIL SEAL AND BEARING

Remove retainers, oil seals and bearings.

Oil seal remover

Bearing puller

09913-50121

09923-73210

Bearing installer

09940-53311
09924-84510
09913-75820
09913-80112

ENGINE 3-38

Service limit

3.0 mm

LOWER END COMPONENTS INSPECTION AND SERVICING

CONROD DEFLECTION AND CONROD
BIG END SIDE CLEARANCE

Wear on the big end of the conrod can be
estimated by checking the movement of the small
end of the rod. This method can also check the
extent of wear on the parts of the conrod's big end.

Push the big end of the conrod to one side and
measure its side clearance with a thickness gauge.

Standard Service limit

1.00 mm0.10 0.45 mm

Where the limit is exceeded, replace crankshaft
assembly or reduce the deflection and the side
clearance to within the limit by replacing the worn
parts conrod, big end bearing, crankpin and
thrust washers, etc. (Refer to the SERVICE DATA)

Service limit

0.05 mm

CRANKSHAFT RUNOUT

Support the crankshaft with "V" blocks as shown,
with the two end journals resting on the blocks.
Position the dial gauge, as shown, and rotate the
crankshaft slowly to read the runout.
Correct or replace the crankshaft if the runout is
greater than the limit.

3-39 ENGINE

CLUTCH DRIVE PLATE

Measure the thickness and claw width of each
drive plate with vernier calipers. Replace drive
plates found to have worn down to the limit.

Vernier calipers

09900-20101

Item

Thickness

Claw width

Standard

2.9 3.1 mm

11.8 12.0 mm

Limit

2.6 mm

11.0 mm

CLUTCH DRIVEN PLATE

Measure each driven plate for distortion with a
thickness gauge. Replace driven plates which
exceed the limit.

Thickness gauge

09900-20803

Service limit

0.1 mm

CLUTCH SPRING FREE LENGTH

Measure the free length of each coil spring with a
vernier calipers, and determine the elastic
strength of each. If any one of springs is not within
the limit, replace all the springs at a time.

Vernier calipers

09900-20101

Service limit

29.5 mm

ENGINE 3-40

CLUTCH RELEASE BEARING

Inspect the release bearing for any abnormality,
particularly cracks, to decide whether it can be
reused or should be replaced.
Smooth engagement and disengagement of the
clutch depends much on the condition of this
bearing.

SHIFTING FORK AND GEAR

Using a thickness gauge, check the shifting fork
clearance in the groove of its gear. If the clearance
limit is exceeded by any of the three gears,
determine whether the gear or the gear shifting
fork should be replaced by measuring the
thickness and groove width.

Thickness gauge

09900-20803

Vernier calipers

09900-20101

Item

Shifting fork
to groove
clearance

Standard

0.10 0.30 mm

Limit

0.50 mm

Shifting fork groove width

Standard

No.1

&

No.2

5.0 5.1 mm

5.5 5.6 mm

No.3

Shifting fork thickness

Standard

No.1

&

No.2

4.8 4.9 mm

5.3 5.4 mmNo.3

3-41 ENGINE

PRIMARY DRIVEN GEAR

Primary dr ven gear is composed as shown.i

Ù Primary driven gear

Damper

Plate

Rivet

Clutch housing

If the internal damper wears, play is generated
between gear and housing, causing abnormal
noise. If the play is extreme, replace the primary
driven gear assembly with a new one.

Service limit

129.9 mm

CAM CHAIN 20-PITCH LENGTH

Pull the chain tight to remove any slack, then
using vernier calipers, measure the 20-pitch (21
pins) length of cam chain. If it measures more than
the limits, replace the cam chain.

CRANKCASE BEARING

Inspect the play of crankcase bearing inner race
by hand while fixing it in the case.
Rotate the inner race by hand to inspect for an
abnormal noise and a smooth rotation. Replace
the bearing if there is something unusual.

STARTER CLUTCH BEARING

Inspect the bearing for any abnormality,
particularly cracks, to decide whether it can be
reused or should be replaced.

5

4

3

1

2

Play

Play

1 2 3 19 20 21

ENGINE 3-42

Decide the width between the webs referring to
the figure below when rebuilding the crankshaft.

STD

width between webs

53.0 0.1 mm

LOWER END COMPONENTS REASSEMBLY

CRANKSHAFT

When mounting the crankshaft in the crankcase,
it is necessary to pull its left end into the
crankcase.

Crankshaft installer

09910-32812

Conrod holder

09910-20116

53.0 0.1 mm

3-43 ENGINE

CAUTION:
Never fit the crankshaft into the crankcase
by striking it with a plastic hammer.
Always use the special tool, otherwise
crankshaft alignment accuracy will be affe cted.

TRANSMISSION

CAUTION:

Never reuse a circlip. After a circlip has been removed from a shaft, it should be discarded and a
new circlip must be installed.
When installing a new circlip, care must be taken not to expand the end gap larger than required
to slip the circlip over the shaft.
After installing a circlip, always insure that it is completely seated in its groove and securely
fitted.

*

*

*

ENGINE 3-44

NOTE:
When reassembling the bearing retainer, apply a small quantity of THREAD LOCK "1342" to the
threaded parts of the bearing retainer screws.
In reassembling the transmission, attention must be given to the locations and positions of
washers and circlips. The cross sectional view given here will serve as a reference for correctly
mounting the gears, washers and circlips.

COUNTERSHAFT

Press-fit 2nd drive gear onto the counter shaft.
Before reassembling, coat the internal face of
the 2nd drive gear with THREAD LOCK SUPER
"1303B and install it so that the length as
shown in Fig.

"

Mounting 2nd drive gear

THREAD LOCK
SUPER "1303B"

THREAD LOCK
1342

99000-32030

99000-32050

Countershaft
length
(Low to 2nd)

A

88.0~88.2 mm

NOTE:

This procedure may be performed only
twice before shaft replacement is required.

*

A

A

A

Washers and circlips thickness

1.2 mm (0.05 in)

1.0 mm (0.04 in)

1.0 mm(0.04 in)

0.5 mm(0.02 in)

A

B

C

D

AA A BDC D B

3-45 ENGINE

Fit the gear shifting cam on the crankcase.
Position the cam as shown in Fig. so that the
gear shifting fork can be installed easily.

GEAR SHIFTING CAM AND FORK

ENGINE 3-46

NOTE:

Two kinds of gear shifting forks, and are
used. They resemble each other very closely in
external appearance and configuration.
Carefully examine the illustration for correct
installing positions and directions.

Ù

After cam stopper and gear shifting forks have
been fitted, hook cam stopper spring onto the
crankcase.

1

2

3-47 ENGINE

CRANKCASE

Coat SUZUKI SUPER GREASE "A" to the lip of
oil seals.
Remove sealant material on the fitting surfaces
of right and left halves of crankcase and thor­oughly remove oil stains.
Fit dowel pins on the left half.
Apply engine oil to the big end of the crankshaft
conrod and all parts of the transmission gears.
Apply SUZUKI BOND No.1215 (99000-31110)
uniformly to the fitting surface of the left half of
the crankcase, and after waiting a few minutes,
fit the right half on the left half.

When reassembling the crankcase pay attention
to the following.

After the crankcase bolts have been tightened,
check if driveshaft and countershaft rotate
smoothly.

If a large resistance is felt to rotation, try to free
the shafts by tapping the driveshaft or
countershaft with a plastic hammer as shown in
Fig.

SUPER

GREASE "A"

SUZUKI

SUZUKI BOND
No.1215

99000-25010

99000-31110

ENGINE 3-48

GEAR SHIFTING CAM DRIVEN GEAR

When installing the gear shifting pawls into the
cam driven gear. The large shoulder must face
to the outside as shown.

A

THREAD LOCK

"1342"

99000-32050

Next, install cam guide and pawl lifter, Apply a
small quantity of THREAD LOCK "1342" to the
threaded parts of the securing screws.

GEAR SHIFTING SHAFT

Install the gear shifting shaft. Match the center
teeth of the gear on the shifting shaft with the
center teeth on the shifting driven gear as
shown.

NOTE:
After the cam driven gear, cam guide, gear
shifting shaft and neutral cam stopper have
been fitted, confirm that gear change is
normal while turning the countershaft and
driveshaft. If gear change is not obtained, it
means that assembly of gears or installation
of gear shifting fork is incorrect. If this is the
case, disassemble and trace the mistake.

PRIMARY DRIVE GEAR AND OIL PUMP

Fit key in the key slot on the crankshaft, and
install the primary drive gear.

A

A

TopTo p

4th4th

3rd3rd

2nd2nd

NN

LowLow

3-49 ENGINE

THREAD LOCK

"1342"

99000-32050

Before mounting the oil pump, apply engine oil
to the sliding surfaces of the case, outer rotor,
inner rotor and shaft.
Apply a small quantity of THREAD LOCK
"1342" to the threaded parts of oil pump
mounting screws.

Tighten the oil pump mounting screws.

NOTE:
After mounting the oil pump in the crankcase,
rotate the pump gear by hand to see if it
turns smoothly.

Conrod holder

09910-20116

After checking the oil pump, install the oil pump
drive gear, lock washer and nut, tighten it with a
torque wrench to the specified torque and bend
up the washer.

NOTE:
This is a left-hand thread nut.

Tightening torque

40 60 N m

(4.0 6.0 kg m)

-

-

DRIVE SHAFT RETAINER

Snap ring pliers

09900-06107

Install the washer and circlip.

Bend up

ENGINE 3-50

CLUTCH

Install the clutch camshaft by positi ning the
face to right side.
Install the oil seal by using the 17 mm socket.

o

Tighten the oil seal retainer screw.

1.5 mm

2.0 mm

3-51 ENGINE

Assemble the clutch, in the reverse order of
disassembly. Pay attention to the following points.

When inserting spacer on countershaft, apply a
small quantity of engine oil to both inside and
outside of the spacer.
Tighten clutch sleeve hub nut using the special
tool to the specified torque;

Clutch sleeve hub
holder

09920-53710

Tightening
torque

30 50 N m

(3.0 5.0 kg m)

-

-

Be sure to lock the nut by firmly bending the
tongue of the washer.

Tighten clutch spring bolts diagonally.

Install drive plates and driven plates to the
sleeve hub.
Insert push rod in the countershaft.

Cam side

Longer

Push Piece
side

Shorter

ENGINE 3-52

Loosen the lock nut, and turn in the release
screw to feel high resistance.
From that position, turn out the release screw

1/4 1/2 turn, and tighten the lock nut.-

Clutch release screw adjustment

When reassembling the clutch cover, fit a
gasket to correctly position as shown in Fig.

CAUTION:
Do not use the old gasket to prevent oil
leakage.

OIL SUMP FILTER

Wash the sump filter with cleaning solvent, and
then blow compressed air through it to dry off
solvent.
After mounting the sump filter, fit the cap and
tighten it.

CAM DRIVE CHAIN

Engage the chain on the sprocket.

Front markFront mark

11//44

3-53 ENGINE

STARTER CLUTCH

THREAD LOCK
SUPER "1303B"

99000-32030

"T" type hexagon
wrench (5 mm)

09911-73730

Tightening torque

Apply THREAD LOCK SUPER "1303B" to allen
bolts and tighten with specified torque.

15 20 N m

(1.5 2.0 kg m)

-

-

MAGNETO ROTOR

Fit key in the key slot on the crankshaft.
Install the magneto rotor.
Apply a small quantity of THREAD LOCK
SUPER to the threaded parts of
crankshaft.
Tighten magneto rotor nut to the specified
torque.

"1305"

THREAD LOCK
SUPER "1305"

99000-32100

Rotor holder

09930-44511

Tightening torque

30 40 N m

(3.0 4.0 kg m)

-

-

1

ENGINE 3-54

STARTER IDLE GEAR AND MOTOR

Install the starter idle gear.

Install the starter motor.

DRIVESHAFT OIL SEAL AND
ENGINE SPROCKET

CAUTION:

Always replace the driveshaft oil seal with
a new one every disassembly to prevent
oil leakage. Also grease the oil seal lip. On
installation, refer to Fig. for correct
position and direction.
Replace "O" ring with a new one every
disassembly.

*

*

NOTE:
After reassembling the LOWER END COM­PONENTS, install the O-ring and spacer.

Oil seal

O-ring

3-55 ENGINE

09930-40113

Tightening torque

Tighten the engine sprocket nut to the specified
torque and bend up the washer.

80 100 N m

(8.0 10.0 kg m)

-

-

Rotor and
Sprocket holder

GEAR POSITION SWITCH

Install gear position switch.

THREAD LOCK
SUPER "1303B"

99000-32030

Apply THREAD LOCK SUPER "1303B" to gear
position switch bolts.

FUEL AND LUBRICATION SYSTEM

CONTENTS

4-1

4-2

4-6

................................................

.............................................

.....................................

4

FUEL COCK

CARBURETOR

LUBRICATION SYSTEM

4-1 FUEL AND LUBRICATION SYSTEM

FUEL COCK

Turn fuel cock to "OFF" position and discon­nect fuel line from the fue cock.l

Place a clean oil pan under the fuel cock
assembly, turn fuel cock to "ON" position and
drain the fuel.
Unscrew the fuel cock securing bolts, and take
off the fuel cock assembly.

CLEANING

Rust from the fuel tank tends to build up in the
filter, which, when the filter has been neglected
for a long period, inhibits the flow of fuel.
Remove the rust from the filter using compressed
air.

DISASSEMBLY

WARNING:
Gasoline is very explosive. Extreme care
must be used.

WARNING:
Gasket must be replaced with a new one to
prevent leakage.

Gasket

FUEL AND LUBRICATION SYSTEM 4-2

CARBURETOR

CARBURETOR CONSTRUCTION

ITEM ITEMSPECIFICATION SPECIFICATION

12.5

37.5

PRE-SET (2,5/8 turn out)

1.25

0.5-1.0

4DH41-2nd

P-0 (390)

£

£

Needle jet (N.J.)
Pilot jet (P.J.)
Starter jet (G.S)
Pilot screw (P.S.)
Pilot air jet (P.A.J.)
Throttle cable play

Jet needle (J,N,)Carburetor type
Bore size
I.D.No.
Idle r/min.
Flat height
Main jet (M.J.)
Main air jet (M.A.J.)

MIKUNI BS26SS

26

26-183

1450 50 r/min

29 0.5

110

0.6

£

A

C

D

A

B

B

C

D

E

E

Unit: mm

Take off the carburetor (Refer to page 3-2and 3)
Remove the carburetor top cover by unscrewing
the cover screws.

.

REMOVAL AND DISASSEMBLY

Remove the float chamber body by unscrewing
the two screws.

Loosen the fitting screw and remove the float.

4-3 FUEL AND LUBRICATION SYSTEM

Remove the throttle valve and spring.

Remove the needle valve retainer and needle
valve.
Remove the main jet.
Remove the needle jet.
Remove the pilot jet.

FUEL AND LUBRICATION SYSTEM 4-4

Remove the main air jet.

If foreign matter is caught between the valve seat
and the needle, the gasoline will continue flowing
and cause it to overflow. If the seat and needle are
worn beyond the permissible limits, similar trouble
will occur. Conversely, if the needle sticks, the
gasoline will not flow into the float chamber. Clean
the float chamber and float parts with gasoline. If
the needle is worn as shown in the illustration,
replace it together with a valve seat. Clean the fuel
passage of the mixing chamber with compressed
air.

NEEDLE VALVE INSPECTION

Reassemble the carburetor by reversing the
sequence of disassembling steps.

REASSEMBLY

NOTE:

Place tongue of diaphragm to carburetor
body properly.

1

4-5 FUEL AND LUBRICATION SYSTEM

Loosen the lock nuts .

Slide the adjuster to obtain the correct play

0.5 1.0 mm.-

Remount the carburetor by reversing the
sequence of removal steps, and following
adjustments and inspection are necessary after
remounting the carburetor.

REMOUNTING

Throttle cable play adjustment

Throttle cable should be adjusted to have correct

play 0.5 1.0 mm.-

A

Idling adjustment
(Refer to page 2-10)

A

2

1

FUEL AND LUBRICATION SYSTEM 4-6

LUBRICATION SYSTEM

CAMSHAFT JOURNAL
AND CAM FACE

ROCKER ARM
SHAFT

CAM CHAIM

CONROD SMALL END

CYLINDER WALL

CONROD BIG
END BEARING

CLUTCH
RELEASE CAM

DRIVESHAFT
BEARING

DRIVESHAFT
AND GEARS

CONTERSHAFT
BEARING

COUNTERSHAFT
AND GEARS

PRIMARY DRIVEN
GEAR SPACER

CLUTCH PLATES

OIL FILTER

OIL PUMP

SUMP FILTER

OIL PAN

4-7 FUEL AND LUBRICATION SYSTEM

CHASSIS

CONTENTS

5-1

5-6

5-12

5-21

5-27

5-35

.............................................

..............................................

............................................

.............................................

..........................

.........................................

5

FRONT WHEEL

FRONT FORK

STEERING STEM

FRONT BRAKE

REAR WHEEL AND REAR BRAKE

REAR SWING ARM

5-1 CHASSIS

FRONT WHEEL

Tightening torque

Item

Nm
36 52
15 25

kg m

3.6 5.2

1.5 2.5

A

B

Support the machine by center stand and jack
or block.

REMOVAL AND DISASSEMBLY

Pull out the cotter pin and remove the axle
nut .

Draw out the axle shaft and take off the wheel.

NOTE:
Do not operate the front brake lever while
dismounting the front wheel.

CHASSIS 5-2

Unlock the washers and remove the four bolts.
Separate the disc plate from the wheel.

CAUTION:
Do not reuse the lock washers.

Using the appropriate drift, drive out the wheel
bearings.

INSPECTION

WHEEL BEARING

Inspect the play of wheel bearings inner race by
hand while fixing it in the wheel hub.
Rotate the inner race by hand to inspect whether
abnormal noise occurs or rotating smoothly.
Replace the bearing if there is something unusual.

AXLE SHAFT

Using the special tools, check the axle shaft for
runout and replace it if the runout exceeds the limit.

Service limit

0.25 mm

Dial gauge(1/100)

Magnetic stand

V-block(100mm)

09900-20606

09900-20701

09900-21304

TIRE

(See page 2-15)

Play

Play

5-3 CHASSIS

Reassemble and remount the front wheel and
front brake in the reverse order of disassembly
and removal, and also carry out the following steps:

REASSEMBLY

Apply grease to the bearings before installing.

WHEEL BEARING

SUZUKI SUPER
GREASE "A"

99000-25010

Install the wheel bearings by using the special
tool.

Bearing installer

09913-75820

NOTE:
Always use new lock washers.

Make sure that the brake disc is clean and free
of any greasy matter, After securing it in place
by tightening its bolts, be sure to lock with
specified torque.

BRAKE DISC

Tightening torque

15 25 N m

(1.5 2.5 kg m)

Bend the washer to the bolts.

SPEEDOMETER GEAR BOX

Before installing the speedometer gear box
grease it and align groove on the wheel hub
with two drive pawls on the speedometer
drive gear box.

When tightening the front axle, check to be sure
that the speedometer gear box is in the position
shown.

SUZUKI SUPER
GREASE "A"

99000-25010

CHASSIS 5-4

FRONT FORK

Tightening torque

Item

Nm
15 30
20 26

kg m

1.5 3.0

2.0 2.6

A

B

Remove the front wheel (See page 5-1).
Remove the two bolts and dismount the front
caliper.

REMOVAL AND DISASSEMBLY