
2-3
MAINTENANCE SPECIFICATIONS
MAINTENANCE SPECIFICATIONS
ENGINEShock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 300 mm (11.81 in)
Rear wheel travel 310 mm (12.20 in)
Electrical:
Ignition system CDI
Generator system AC magneto
Battery type YTZ7S (F)
Battery voltage/capacity 12V/6 AH
Specific gravity 1.31
Headlight type: Quartz bulb (halogen)
Bulb wattage × quantity:
Headlight 12 V 35/36.5 W × 1
Taillight 12 V 1.6/0.3 W × 1
Item Standard Limit
Cylinder head:
Warp limit ---- 0.05 mm (0.002
in)
Cylinder:
Bore size 77.000–77.010 mm (3.0315–3.0319 in) ----
Out of round limit ---- 0.05 mm (0.002
in)
Camshaft:
Drive method Chain drive (Left) ----
Camshaft cap inside diameter 22.000–22.021 mm (0.8661–0.8670 in) ----
Camshaft outside diameter 21.959–21.972 mm (0.8645–0.8650 in) ----
Shaft-to-cap clearance 0.028–0.062 mm (0.0011–0.0024 in) 0.08 mm (0.003
in)
Cam dimensions

2-8
MAINTENANCE SPECIFICATIONS
CHASSISCarburetor: ZA, AUS, NZ EUROPE
Type/manufacturer FCR-MX37/KEIHIN←----
I. D. mark 5UME E0 5UML L0 ----
Main jet (M.J) #170 #160 ----
Main air jet (M.A.J) #115←----
Jet needle (J.N) NJRU NNGU ----
Cutaway (C.A) 1.5←----
Pilot jet (P.J) #42 #45 ----
Pilot air jet (P.A.J) #70←----
Pilot outlet (P.O) ø0.9←----
Bypass (B.P) ø1.0←----
Valve seat size (V.S) ø3.8←----
Starter jet (G.S) #68←----
Leak jet (Acc.P) #70←----
Float height (F.H) 8.0 mm (0.31 in)←----
Engine idle speed 1,750–1,950 r/min←----
Intake vacuum 31.0–37.0 kPa
(233–278 mmHg,
9.2–10.9 inHg)←----
Hot starter lever free play 3–6 mm (0.12–0.24
in)←----
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less (0.0047 in or less) 0.20 mm (0.008
in)
Side clearance 0.090–0.170 mm (0.0035–0.0067 in) 0.24 mm
(0.0094 in)
Housing and rotor clearance 0.03–0.10 mm (0.0012–0.0039 in) 0.17 mm
(0.0067 in)
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height 240.0 mm (9.45 in) ----
Thickness 22.0 mm (0.87 in) ----
Radiator cap opening pressure 95.0–125.0 kPa (0.95–1.25 kg/cm
2, 13.8–
18.1 psi)----
Radiator capacity (total) 0.54 L (0.48 Imp qt, 0.57 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
Item Standard Limit
Steering system:
Steering bearing typeTaper roller bearing ----

2-12
TIGHTENING TORQUES
TIGHTENING TORQUES
ENGINE
△- marked portion shall be checked for torque tightening after break-in or before each race.
ItemThread
sizeQ'ty Tightening torque Remarks
Spark plug M10S 1 13 Nm (1.3 m•kg, 9.4 ft•lb)
Camshaft cap M6 10 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head blind plug screw M12 1 28 Nm (2.8 m•kg, 20 ft•lb)
Cylinder head (stud bolt) M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Cylinder head (stud bolt) M8 1 15 Nm (1.5 m•kg, 11 ft•lb)
Cylinder head (bolt) M9 4 38 Nm (3.8 m•kg, 27 ft•lb)
Cylinder head (nut) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder head cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Cylinder M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer weight M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Balancer shaft driven gear M14 1 50 Nm (5.0 m•kg, 36 ft•lb) Lock washer
Timing chain guide (intake side) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Timing chain tensioner cap bolt M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Impeller M8 1 14 Nm (1.4 m•kg, 10 ft•lb)
Radiator hose clamp M6 10 2 Nm (0.2 m•kg, 1.4 ft•lb)
Coolant drain bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)Copper
washer
Water pump housing M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator stay M6 6 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator M6 4 10 Nm (1.0 m•kg, 7.2 ft•lb)
Radiator pipe M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil pump cover M4 1 1.7 Nm (0.17 m•kg, 1.2 ft•lb)
Oil pump M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil filter element drain bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil filter element cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil strainer (crankcase) M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Oil delivery pipe 1 (M10) M10 1 20 Nm (2.0 m•kg, 14 ft•lb)Copper
washer
Oil delivery pipe 1 (M8) M8 2 18 Nm (1.8 m•kg, 13 ft•lb)Copper
washer
△Oil hose M6 3 8 Nm (0.8 m•kg, 5.8 ft•lb)
Oil hose clamp — 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
Oil strainer (oil tank) M6 1 9 Nm (0.9 m•kg, 6.5 ft•lb)
Oil tank drain bolt M8 1 18 Nm (1.8 m•kg, 13 ft•lb)
Oil tank (upper) M6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Oil tank and frame M6 3 9 Nm (0.9 m•kg, 6.5 ft•lb)
Oil pressure check bolt M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Carburetor joint M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Carburetor joint clamp M4 2 3 Nm (0.3 m•kg, 2.2 ft•lb)
Air filter joint clamp M6 1 3 Nm (0.3 m•kg, 2.2 ft•lb)

3-1
MAINTENANCE INTERVALS FOR COMPETITION USE
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS FOR COMPETITION USE
• The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind that such factors as
weather, terrain, geographical location, and individual usage will alter the required maintenance and lubrication intervals.
If you are a doubt as to what intervals to follow in maintaining and lubricating your machine, consult your Yamaha dealer.
• Periodic inspection is essential in making full use of the machine performance. The service life of the parts varies sub-
stantially according to the environment in which the machine runs (e.g., rain, dirt, etc.). Therefore, earlier inspection is
required by reference to the list below.
ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks
ENGINE OIL
Replace●●
VALVES
Check the valve clearances●●The engine must be cold.
Inspect●Check the valve seats and valve
stems for wear.
Replace●
VALVE SPRINGS
Inspect●Check the free length and the tilt.
Replace●
VALVE LIFTERS
Inspect●Check for scratches and wear.
Replace●
CAMSHAFTS Inspect the camshaft surface.
Inspect●Inspect the decompression system.
Replace●
CAMSHAFT SPROCKETS
Inspect●Check for wear on the teeth and for
damage.
Replace●
PISTON
Inspect●●Inspect crack.
Clean●Inspect carbon deposits and eliminate
them.
Replace●It is recommended that the piston pin
and ring are also replaced at the same
time.
PISTON RING
Inspect●Check ring end gap.
Replace●●
PISTON PIN
Inspect●
Replace●
CYLINDER HEAD Inspect carbon deposits and eliminate
them.
Inspect and clean●Change gasket.

3-3
MAINTENANCE INTERVALS FOR COMPETITION USE
OIL FILTER
Replace●●
ENGINE GUARD
Replace●Breakage
FRAME
Clean and inspect●●
FUEL TANK, COCK
Clean and inspect●●
BRAKES
Adjust lever position and pedal
height●●
Lubricate pivot point●●
Check brake disc surface●●
Check fluid level and leakage●●
Retighten brake disc bolts, cali-
per bolts, master cylinder bolts
and union bolts●●
Replace pads●
Replace brake fluid●Every one year
FRONT FORKS
Inspect and adjust●●
Replace oil●●Suspension oil "S1"
Replace oil seal●
FRONT FORK OIL SEAL AND
DUST SEAL
Clean and lube●●Lithium base grease
PROTECTOR GUIDE
Replace●
REAR SHOCK ABSORBER
Inspect and adjust●●
Lube●(After
rain
ride)●Molybdenum disulfide grease
Retighten●●
DRIVE CHAIN GUIDE AND
ROLLERS
Inspect●●
SWINGARM
Inspect, lube and retighten●●Molybdenum disulfide grease
RELAY ARM, CONNECTING
ROD
Inspect, lube and retighten●●Molybdenum disulfide grease
SIDESTAND
Lubricate●Lithium base grease ItemAfter
break-
inEvery
race
Every
third
(or 500
km)Every
fifth (or
1,000
km)
As re-
quiredRemarks

3-5
PRE-OPERATION INSPECTION AND MAINTENANCE
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation or practice, make sure the machine is in good operating condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap. Check the cool-
ing system for leakage.P.3-9 – 10
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage.P.1-18
Engine oilCheck that the oil level is correct. Check the crankcase and oil
line for leakage.P.3-12 – 13
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-10 – 11
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-11
Brakes Check the play of front brake and effect of front and rear brake. P.3-17 – 20
Drive chainCheck drive chain slack and alignment. Check that the drive chain
is lubricated properly.P.3-20 – 21
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-24
SteeringCheck that the handlebar can be turned smoothly and have no ex-
cessive play.P.3-24 – 25
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage.
P.3-21 – 24
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.—
Exhaust pipe Check that the exhaust pipe is tightly mounted and has no cracks. P.3-8 – 9
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-20
Lubrication Check for smooth operation. Lubricate if necessary. P.3-26
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-20
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the course and
weather or by taking into account the results of test runs before
riding? Are inspection and maintenance completely done?P.4-1 – 10

3-10
ENGINE
• Do not mix more than one type of
ethylene glycol antifreeze con-
taining corrosion inhibitors for
aluminum engine.
• Do not use water containing im-
purities or oil.
Handling notes of coolant:
The coolant is harmful so it should be
handled with special care.
• When coolant splashes to your
eye.
Thoroughly wash your eye with
water and see your doctor.
• When coolant splashes to your
clothes.
Quickly wash it away with water
and then with soap.
• When coolant is swallowed.
Quickly make him vomit and take
him to a doctor.
9. Install:
• Radiator cap
Start the engine and warm it up
for a several minutes.
10. Check:
• Coolant level
Coolant level low→Add coolant.
CHECKING THE RADIATOR CAP
1. Inspect:
• Seal (radiator cap) "1"
• Valve and valve seat "2"
Crack/damage→Replace.
Exist fur deposits "3" →Clean or
replace.CHECKING THE RADIATOR CAP
OPENING PRESSURE
1. Attach:
• Radiator cap tester "1" and adapt-
er "2"
Apply water on the radiator cap seal.
3. Radiator cap
2. Apply the specified pressure.
3. Inspect:
•Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds→
Replace.
CHECKING THE COOLING
SYSTEM
1. Inspect:
• Coolant level
2. Attach:
• Radiator cap tester "1" and adapt-
er "2"
3. Apply the specified pressure.
• Do not apply pressure more than
specified pressure.
• Radiator should be filled fully.
4. Inspect:
• Pressure
Impossible to maintain the speci-
fied pressure for 10 seconds→
Repair.
•Radiator "1"
• Radiator hose joint "2"
Coolant leakage→Repair or re-
place.
• Radiator hose "3"
Swelling→Replace.
ADJUSTING THE CLUTCH LEVER
FREE PLAY
1. Check:
• Clutch lever free play "a"
Out of specification→Adjust.
2. Adjust:
• Clutch lever free play
Clutch lever free play adjustment
steps:
a. Loosen the locknuts "1".
b. Adjust the free play by changing
their tightening position.
c. Tighten the locknuts.
• Make minute adjustment on the le-
ver side using the adjuster "2".
• After adjustment, check proper op-
eration of clutch lever.
Radiator cap tester:
YU-24460-A/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Radiator cap opening
pressure:
95.0–125.0 kPa (0.95–
1.25 kg/cm
2, 13.8–18.1
psi)
Radiator cap tester:
YU-24460-A/90890-
01325
Radiator cap tester
adapter:
YU-33984/90890-01352
Standard pressure:
180 kPa (1.8 kg/cm
2,
25.6 psi)
Clutch lever free play "a"
:
8.0–13.0 mm (0.31–0.51
in)
Locknut:
7 Nm (0.7 m•kg, 5.1
ft•lb)

3-12
ENGINE
4. Clean:
• Air filter element
Clean them with solvent.
After cleaning, remove the remaining
solvent by squeezing the element.
• Do not twist the element when
squeezing the element.
• Leaving too much of solvent in
the element may result in poor
starting.
5. Inspect:
• Air filter element
Damage→Replace.
6. Apply:
• Foam-air-filter oil or equivalent oil
to the element
• Squeeze out the excess oil. Ele-
ment should be wet but not drip-
ping.
• Wipe off the oil left on the element
surface using a clean dry cloth. (Ex-
cess oil in the element may ad-
versely affect engine starting.)
7. Install:
• Air filter guide "1"
• Align the projection "a" on filter
guide with the hole "b" in air filter el-
ement.
• Apply the lithium soap base grease
on the matching surface "c" on air
filter element.
8. Install:
• Air filter element "1"
Align the projection "a" on filter guide
with the hole "b" in air filter case.
9. Hook:
• Binder "1"
Hook the binder "1" so that it contacts
the filter guide projections "a".
CHECKING THE ENGINE OIL
LEVEL
1. Start the engine, warm it up for
several minutes, and then turn off
the engine and wait for five min-
utes.
2. Place the machine on a level
place and hold it up on upright po-
sition by placing the suitable
stand under the engine.
3. Inspect:
• Oil level
Oil should be up to the full level in
the check window "1".
Level check window is not full. →
Add 0.2 L (0.18 Imp qt, 0.21 US
qt) of oil.
• Engine oil also lubricates the
clutch and the wrong oil types or
additives could cause clutch
slippage. Therefore, do not add
any chemical additives or use en-
gine oils with a grade of CD or
higher and do not use oils la-
beled "ENERGY CONSERVING
II".
• Do not allow foreign materials to
enter the crankcase.
4. Install:
• Oil tank cap
5. Start the engine and let it warm up
for several minutes.
6. Turn off the engine and inspect
the oil level once again.
Wait a few minutes until the oil settles
before inspecting the oil level.
CHANGING THE ENGINE OIL
1. Start the engine and warm it up
for several minutes, and then turn
off the engine and wait for five
minute.
2. Place the machine on a level
place and hold it on upright posi-
tion by placing the suitable stand
under the engine.
3. Place a suitable container under
the engine.
4. Remove:
• Engine guard "1"
• Bolt (oil tank) "2"
• Washer "3"
• Oil filler cap "4"
• Oil tank drain bolt "5"
• Crankcase oil drain bolt "6"
• Oil filter element drain bolt "7"
Drain the crankcase and oil tank
of its oil.
Recommended brand:
YAMALUBE
Recommended engine
oil type
SAE 10W-30, SAE 10W-
40, SAE 10W-50, SAE
15W-40, SAE 20W-40 or
SAE 20W-50
Recommended engine
oil grade
API service SG type or
higher, JASO standard
MA