
2-12
TIGHTENING TORQUES
Cylinder head (stud bolt)M8 × 1.25 1 15 1.5 11
Cylinder head (bolt) M9 × 1.25 4 38 3.8 27
Cylinder head (nut) M6 × 1.0 2 10 1.0 7.2
Cylinder head cover M6 × 1.0 2 10 1.0 7.2
Cylinder M6 × 1.0 1 10 1.0 7.2
Balancer weight M6 × 1.0 2 10 1.0 7.2
Balancer shaft driven gear M14 × 1.0 1 50 5.0 36
Timing chain guide (intake side) M6 × 1.0 2 10 1.0 7.2
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Timing chain tensioner cap bolt M6 × 1.0 1 7 0.7 5.1
Impeller M8 × 1.25 1 14 1.4 10
Radiator hose clamp M6 × 1.0 10 2 0.2 1.4
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Water pump housing M6 × 1.0 4 10 1.0 7.2
Radiator stay M6 × 1.0 6 10 1.0 7.2
Radiator M6 × 1.0 4 10 1.0 7.2
Radiator pipe M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 2 0.2 1.4
Oil pump M6 × 1.0 3 10 1.0 7.2
Oil filter element drain bolt M6 × 1.0 1 10 1.0 7.2
Oil filter element cover M6 × 1.0 2 10 1.0 7.2
Oil strainer (crankcase) M6 × 1.0 2 10 1.0 7.2
Oil delivery pipe 1 (M10) M10 × 1.25 1 20 2.0 14
Oil delivery pipe 1 (M8) M8 × 1.25 2 18 1.8 13
Oil hose M6 × 1.0 2 8 0.8 5.8
△ Oil hose clamp —2 2 0.2 1.4
Oil strainer (oil tank) M6 × 1.0 1 9 0.9 6.5
Oil tank drain bolt M8 × 1.25 1 18 1.8 13
Oil tank (upper) M6 × 1.0 1 7 0.7 5.1
Oil tank and frame M6 × 1.0 3 9 0.9 6.5
Oil pressure check bolt M6 × 1.0 1 10 1.0 7.2
Carburetor joint M6 × 1.0 2 10 1.0 7.2
Carburetor joint clamp M4 × 0.7 2 3 0.3 2.2
Air filter joint clamp M6 × 1.0 1 3 0.3 2.2
Throttle cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Throttle cable (pull) M6 × 1.0 1 4 0.4 2.9
Throttle cable (return) M12 × 1.0 1 11 1.1 8.0
Throttle cable cover M5 × 0.8 2 4 0.4 2.9
Hot starter plunger M12 × 1.0 1 2 0.2 1.4
Hot starter cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
△ Air filter case M6 × 1.0 2 8 0.8 5.8
Air filter joint and air filter case M5 × 0.8 1 4 0.4 2.9
Exhaust pipe M8 × 1.25 2 20 2.0 14
△ Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb

2-13
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque ti ghtening after break-in or before each race.
△Silencer M8 × 1.25 2 30 3.0 22
Silencer clamp M8 × 1.25 1 16 1.6 11
Spark arrester M5 × 0.8 4 7 0.7 5.1
Silencer cap M5 × 0.8 6 5 0.5 3.6
Air induction pipe M6 × 1.0 1 10 1.0 7.2
Air induction pipe clamp M6 × 1.0 1 4 0.4 2.9
Air cut-off valve assembly and bracket M6 × 1.0 2 10 1.0 7.2
Bracket (air cut-off valve) and frame M6 × 1.0 2 7 0.7 5.1
Crankcase M6 × 1.0 11 12 1.2 8.7
Crankcase bearing stopper M6 × 1.0 11 10 1.0 7.2
Crankcase bearing stopper (crankshaft) M6 × 1.0 4 14 1.4 10
Left crankcase cove r M6 × 1.0 8 10 1.0 7.2
Idle gear cover (starter motor) M6 × 1.0 3 10 1.0 7.2
Idle gear plate M6 × 1.0 2 10 1.0 7.2
Right crankcase cove r M6 × 1.0 6 10 1.0 7.2
Clutch cover M6 × 1.0 7 10 1.0 7.2
Crankcase oil drain bolt M10 × 1.25 1 20 2.0 14
△ Crankshaft end accessing screw M32 × 1.5 1 — — —
△ Timing mark accessing screw M14 × 1.5 1 — — —
Drive chain sprocket cover M6 × 1.0 2 8 0.8 5.8
Kick shaft ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kickstarter crank M8 × 1.25 1 33 3.3 24
Primary drive gear M18 × 1.0 1 75 7.5 54
Clutch spring M6 × 1.0 5 10 1.0 7.2
Clutch boss M16 × 1.0 1 60 6.0 43
Clutch cable locknut M8 × 1.25 2 7 0.7 5.1
Push lever shaft M6 × 1.0 1 10 1.0 7.2
Drive sprocket M18 × 1.0 1 75 7.5 54
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Shift pedal M6 × 1.0 1 12 1.2 8.7
Part to be tightened
Thread size Q'tyTightening torque
Nm m•kg ft•lb
Part to be tightened Thread size Q'tyTightening torque
Nm m•kg ft•lb
△ Upper bracket and outer tube M8 × 1.25 4 21 2.1 15
△ Lower bracket and outer tube M8 × 1.25 4 21 2.1 15
△ Upper bracket and steeri ng stem M24 × 1.0 1 145 14.5 105
△ Handlebar upper holder and handlebar lower holder M8 × 1.25 4 28 2.8 20
△ Handlebar lower holder and upper bracket M10 × 1.25 2 34 3.4 24
△ Steering stem and steering ring nut M28 × 1.0 1Refer to NOTE.

3-1
MAINTENANCE INTERVALS
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maint enance 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 maintaini ng and lubricating your machine, consult your Yamaha dealer.
ItemAfter
break- in Every
race
Every third
(or 500
km) Every
fifth (or 1,000
km)
As re-
quired Remarks
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 ●
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.
CYLINDER Inspect and clean ●Inspect score marks.
Replace ●Inspect wear.

3-2
MAINTENANCE INTERVALS
CLUTCHInspect and adjust ●● Inspect housing, friction plate, clutch
plate and spring.
Replace ●
TRANSMISSION Inspect ●
Replace bearing ●
SHIFT FORK, SHIFT CAM,
GUIDE BAR Inspect ●Inspect wear.
ROTOR NUT Retighten ●●
MUFFLER Inspect and retighten ●●
Clean ●
Replace ●
CRANK Inspect and clean ●●
CARBURETOR Inspect, adjust and clean ●●
AIR INDUCTION SYSTEM Inspect and clean ●● ●●
SPARK PLUG Inspect and clean ●●
Replace ●
DRIVE CHAIN Use chain lube.
Lubricate, slack, alignment ●● Chain slack: 48–58 mm (1.9–2.3 in)
Replace ●
COOLING SYSTEM Check coolant level and leakage ●●
Check radiator cap operation ●
Replace coolant ●Every two years
Inspect hoses ●
OUTSIDE NUTS AND BOLTS Retighten ●● Refer to "STARTING AND BREAK-
IN" section in the CHAPTER 1.
AIR FILTER Clean and lubricate ●● Use foam air-filter oil or equivalent oil.
Replace ●
OIL FILTER Replace ●●
FRAME Clean and inspect ●●
Item
After
break- in Every
race
Every third
(or 500 km) Every
fifth (or
1,000 km)
As re-
quired Remarks
3

3-3
MAINTENANCE INTERVALS
FUEL TANK, COCKClean 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
STEERING HEAD Inspect free play and retighten ●●
Clean and lube ●Lithium base grease
Replace bearing ●
Item
After
break- in Every
race
Every third
(or 500 km) Every
fifth (or
1,000 km)
As re-
quired Remarks

3-4
MAINTENANCE INTERVALS
TIRE, WHEELSInspect air pressure, wheel run-
out, tire wear and spoke loose-
ness ●●
Retighten sprocket bolt ●●
Inspect bearings ●
Replace bearings ●
Lubricate ●Lithium base grease
THROTTLE, CONTROL CABLE Check routing and connection ●●
Lubricate ●● Yamaha cable lube or SAE 10W-30
motor oil
HOT STARTER, CLUTCH LEVER Inspect free play ●
BATTERY Check terminal for looseness
and corrosion ●
Item
After
break- in Every
race
Every third
(or 500 km) Every
fifth (or
1,000 km)
As re-
quired Remarks

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 MAINTENANCEItem RoutinePage
Coolant Check that coolant is filled up to the radiator cap. Check the cool-
ing system for leakage. P.3-9 – 10
Fuel Check that a fresh gasoline is filled in the fuel tank. Check the fuel
line for leakage.
P.1-14
Engine oil Check that the oil level is correct. Check the crankcase and oil line
for leakage. P.3-12 – 14
Gear shifter and clutch Check that gears can be shifted correctly in order and that the
clutch operates smoothly. P.3-10
Throttle grip/Housing Check that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.
P.3-10 – 11
Brakes Check the play of front brake and ef fect of front and rear brake. P.3-17 – 20
Drive chain Check drive chain slack and alignment. Check that the drive chain
is lubricated properly. P.3-20 – 21
Wheels Check for excessive wear and ti
re pressure. Check for loose
spokes and have no excessive play. P.3-24
Steering Check that the handlebar can be turned smoothly and have no ex-
cessive play.
P.3-24 – 25
Front forks and rear shock
absorber Check 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 mount ed 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.1-16
Lead connectors Check that the AC magneto, CDI unit, and ignition coil are con-
nected tightly. P.1-3
Settings Is the machine set suitably for the
condition of the racing course
and weather or by taking into account the results of test runs be-
fore racing? Are inspection and maintenance completely done? P.4-1 – 9

3-9
ENGINE
CHECKING THE SILENCER AND
EXHAUST PIPE
1. Inspect:• Gasket "1"
Damage →Replace.
INSTALLING THE SILENCER AND
EXHAUST PIPE
1. Install: • Gasket
• Exhaust pipe "1"
• Nut (exhaust pipe) "2"
First, temporarily install both nuts,
then tighten either of these nuts to 13
Nm (1.3 m•kg, 9.4 ft•lb) and the other
to 20 Nm (2.0 m•kg, 14 ft•lb), and
then come back to the first one and
retighten it to 20 Nm (2.0 m•kg, 14
ft•lb).
2. Install: • Silencer clamp "1"
• Gasket "2"
• Silencer
• Washer "4"
• Bolt (silencer) "5" CHECKING THE COOLANT LEVEL
Do not remove the radiator cap
"1", drain bolt and hoses when the
engine and radiator are hot. Scald-
ing hot fluid and steam may be
blown out under pressure, which
could cause serious injury. When
the engine has cooled, place a
thick towel over the radiator cap,
slowly rotate the cap counter-
clockwise to the detent. This pro-
cedure allows any residual
pressure to escape. When the
hissing sound has stopped, press
down on the cap while turning
counterclockwise and remove it.
Hard water or salt water is harmful
to the engine parts. You may use
distilled water, if you can't get soft
water.
1. Place the machine on a level
place, and hold it in an upright po-
sition.
2. Remove: • Radiator cap
3. Check: • Coolant level "a"Coolant level low →Add coolant.
1. Radiator
CHANGING THE COOLANT
Do not remove the radiator cap
when the engine is hot.
Take care so that coolant does not
splash on painted surfaces. If it
splashes, wash it away with water.
1. Place a container under the en- gine. 2. Remove:
• Seat
• Left side cover
3. Remove the catch tank hose from
the catch tank and drain the tank
of its coolant.
4. Remove:
• Coolant drain bolt "1"
5. Remove: • Radiator capDrain the coolant completely.
6. Clean: • Cooling systemThoroughly flush the cooling sys-
tem with clean tap water.
7. Install: • Copper washer
• Coolant drain bolt
8. Fill: •Radiator
• EngineTo specified level.
• 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.
Nut (exhaust pipe):
20 Nm (2.0 m•kg, 14
ft•lb)
Silencer clamp: 16 Nm (1.6 m•kg, 11
ft•lb)
Bolt (silencer): 30 Nm (3.0 m•kg, 22
ft•lb)
Coolant drain bolt:10 Nm (1.0 m•kg, 7.2
ft•lb)
Recommended coolant: High quality ethylene
glycol anti-freeze con-
taining anti-corrosion
for aluminum engine
Coolant "1" and water
(soft water) "2" mixing ra-
tio: 50%/50%
Coolant capacity: 0.99 L (0.87 Imp qt, 1.05
US qt)