
2-13
TIGHTENING TORQUES
Throttle cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (pull) M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Throttle cable (return) M12 1 11 Nm (1.1 m•kg, 8.0 ft•lb)
Throttle cable cover M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter plunger M12 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Hot starter cable adjust bolt and locknut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Air filter case M6 2 8 Nm (0.8 m•kg, 5.8 ft•lb)
Air filter joint and air filter case M5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Exhaust pipe M8 2 20 Nm (2.0 m•kg, 14 ft•lb)
△Exhaust pipe protector M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Silencer M8 2 30 Nm (3.0 m•kg, 22 ft•lb)
Silencer clamp M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Spark arrester M5 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
Silencer cap M5 6 5 Nm (0.5 m•kg, 3.6 ft•lb)
Air induction pipe M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Air induction pipe clamp M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Air cut-off valve assembly and bracket M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Bracket (air cut-off valve) and frame M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Crankcase M6 11 12 Nm (1.2 m•kg, 8.7 ft•lb)
Crankcase bearing stopper M6 11 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase bearing stopper (crankshaft) M6 4 14 Nm (1.4 m•kg, 10 ft•lb) Stake.
Left crankcase cover M6 8 10 Nm (1.0 m•kg, 7.2 ft•lb)
Idle gear cover (starter motor)M6 3 10 Nm (1.0 m•kg, 7.2 ft•lb)
Idle gear plate M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Right crankcase cover M6 6 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch cover M6 7 10 Nm (1.0 m•kg, 7.2 ft•lb)
Crankcase oil drain bolt M10 1 20 Nm (2.0 m•kg, 14 ft•lb)Copper
washer
△Crankshaft end accessing screw M32 1 —
△Timing mark accessing screw M14 1 —
Drive chain sprocket cover M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Kick shaft ratchet wheel guide M6 2 12 Nm (1.2 m•kg, 8.7 ft•lb) Lock washer
Kickstarter lever M8 1 33 Nm (3.3 m•kg, 24 ft•lb)
Primary drive gear M18 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch spring M6 5 10 Nm (1.0 m•kg, 7.2 ft•lb)
Clutch boss M16 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Clutch cable locknut M8 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Push lever shaft M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Drive sprocket M18 1 75 Nm (7.5 m•kg, 54 ft•lb) Lock washer
Drive axle oil seal stopper M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Segment M8 1 30 Nm (3.0 m•kg, 22 ft•lb)
Shift guide M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Stopper lever M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Shift pedal M6 1 12 Nm (1.2 m•kg, 8.7 ft•lb)ItemThread
sizeQ'ty Tightening torque Remarks

2-14
TIGHTENING TORQUES
CHASSIS
△- marked portion shall be checked for torque tightening after break-in or before each race.
ItemThread
sizeQ'ty Tightening torque Remarks
△Upper bracket and outer tube M84 21 Nm (2.1 m•kg, 15 ft•lb)
△Lower bracket and outer tube M8 4 21 Nm (2.1 m•kg, 15 ft•lb)
△Upper bracket and steering stem M24 1 145 Nm (14.5 m•kg, 105 ft•lb)
△Handlebar upper holder and handlebar
lower holderM8 4 28 Nm (2.8 m•kg, 20 ft•lb)
△Handlebar lower holder and upper brack-
etM10 2 34 Nm (3.4 m•kg, 24 ft•lb)
△Steering stem and steering ring nut M28 1 Refer to TIP.
Front fork and front fork cap bolt M51 2 30 Nm (3.0 m•kg, 22 ft•lb)
Front fork and base valve M30 2 55 Nm (5.5 m•kg, 40 ft•lb)Copper
washer
Front fork cap bolt and damper rod M12 2 29 Nm (2.9 m•kg, 21 ft•lb)
Front fork bleed screw and front fork cap
boltM5 2 1 Nm (0.1 m•kg, 0.7 ft•lb)
△Front fork and front fork protector M6 6 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Front fork protector and brake hose hold-
erM6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Throttle grip cap M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Start switch M3 1 0.5 Nm (0.05 m•kg, 0.36 ft•lb)
Engine stop switch M3 1 0.5 Nm (0.05 m•kg, 0.36 ft•lb)
△Front brake master cylinder M6 29 Nm (0.9 m•kg, 6.5 ft•lb)
Brake lever mounting bolt M6 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
Brake lever mounting nut M6 1 6 Nm (0.6 m•kg, 4.3 ft•lb)
Brake lever position locknut M6 1 5 Nm (0.5 m•kg, 3.6 ft•lb)
△Front brake hose guide and front brake
hose guide bracketM5 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
△Front brake hose guide and lower bracket M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Clutch lever holder M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Clutch lever mounting nut M6 1 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter lever holder M5 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Hot starter lever mounting nut M5 1 2 Nm (0.2 m•kg, 1.4 ft•lb)
Front brake master cylinder cap M4 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
△
Front brake hose union bolt M10 2 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Front brake caliper M8 2 23 Nm (2.3 m•kg, 17 ft•lb)
△Front brake caliper and brake hose holder M6 1 10 Nm (1.0 m•kg, 7.2 ft•lb)
Pad pin plug M10 2 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Front brake caliper and pad pin M10 1 18 Nm (1.8 m•kg, 13 ft•lb)
△Rear brake caliper and pad pin M10 1 18 Nm (1.8 m•kg, 13 ft•lb)
△Brake caliper and bleed screw M8 2 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Front wheel axle and axle nut M16 1 90 Nm (9.0 m•kg, 65 ft•lb)
△Front wheel axle holder M8 4 21 Nm (2.1 m•kg, 15 ft•lb)

2-15
TIGHTENING TORQUES
△Front brake disc M6 6 12 Nm (1.2 m•kg, 8.7 ft•lb)
△Rear brake disc M6 6 14 Nm (1.4 m•kg, 10 ft•lb)
△Brake pedal M8 1 26 Nm (2.6 m•kg, 19 ft•lb)
△Rear brake master cylinder M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
Rear brake master cylinder cap M4 2 2 Nm (0.2 m•kg, 1.4 ft•lb)
△
Rear brake hose union bolt M10 2 30 Nm (3.0 m•kg, 22 ft•lb)Copper
washer
△Rear wheel axle and axle nut M20 1 125 Nm (12.5 m•kg, 90 ft•lb)
△Nipple (spoke) — 72 3 Nm (0.3 m•kg, 2.2 ft•lb)
△Rear wheel sprocket M8 6 50 Nm (5.0 m•kg, 36 ft•lb)
△Rear brake disc cover M6 2 10 Nm (1.0 m•kg, 7.2 ft•lb)
△Rear brake caliper protector M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
Drive chain puller adjust bolt and locknut M8 2 19 Nm (1.9 m•kg, 13 ft•lb)
Engine mounting:
△Engine and engine bracket (front) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Engine and frame (lower) M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Upper engine bracket and frame M8 4 34 Nm (3.4 m•kg, 24 ft•lb)
△Lower engine bracket and frame M8 4 34 Nm (3.4 m•kg, 24 ft•lb)
△Engine and engine bracket (upper) M10 1 55 Nm (5.5 m•kg, 40 ft•lb)
△Engine guard M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Regulator M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Pivot shaft and nut M16 1 85 Nm (8.5 m•kg, 61 ft•lb)
△Relay arm and swingarm M14 1 70 Nm (7.0 m•kg, 50 ft•lb)
△Relay arm and connecting rod M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Connecting rod and frame M14 1 80 Nm (8.0 m•kg, 58 ft•lb)
△Rear shock absorber and frame M10 1 56 Nm (5.6 m•kg, 40 ft•lb)
△Rear shock absorber and relay arm M10 1 53 Nm (5.3 m•kg, 38 ft•lb)
△Rear frame (upper) M8 1 38 Nm (3.8 m•kg, 27 ft•lb)
△Rear frame (lower) M8 2 32 Nm (3.2 m•kg, 23 ft•lb)
△Swingarm and brake hose holder M54 3 Nm (0.3 m•kg, 2.2 ft•lb)
Swingarm and patch M4 4 2 Nm (0.2 m•kg, 1.4 ft•lb)
Upper drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Lower drive chain tensioner M8 1 16 Nm (1.6 m•kg, 11 ft•lb)
Drive chain support M6 3 7 Nm (0.7 m•kg, 5.1 ft•lb)
Seal guard and swingarm M5 4 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Fuel tank M6 2 9 Nm (0.9 m•kg, 6.5 ft•lb)
△Fuel cock M6 2 4 Nm (0.4 m•kg, 2.9 ft•lb)
Seat set bracket and fuel tankM6 1 7 Nm (0.7 m•kg, 5.1 ft•lb)
Fuel tank bracket and fuel tank M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Air scoop and fuel tank M6 6 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Air scoop and radiator guard (lower) M6 2 6 Nm (0.6 m•kg, 4.3 ft•lb)
△Front fender M6 4 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Rear fender (front) M6 2 7 Nm (0.7 m•kg, 5.1 ft•lb)
△Rear fender (rear) M6 2 11 Nm (1.1 m•kg, 8.0 ft•lb)ItemThread
sizeQ'ty Tightening torque Remarks

3-4
MAINTENANCE INTERVALS FOR COMPETITION USE
STEERING HEAD
Inspect free play and retighten●●
Clean and lube●Lithium base grease
Replace bearing●
TIRE, WHEELS
Inspect 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-40
motor oil
HOT STARTER, CLUTCH LEVER
Inspect free play●
BATTERY
Check terminal for looseness
and corrosion● 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

3-19
CHASSIS
3. Inspect:
• Brake fluid level
Refer to "CHECKING THE
BRAKE FLUID LEVEL" section.
4. Check:
• Brake lever operation
A softy or spongy feeling→Bleed
brake system.
Refer to "BLEEDING THE HY-
DRAULIC BRAKE SYSTEM" sec-
tion.
CHECKING AND REPLACING THE
REAR BRAKE PADS
1. Inspect:
• Brake pad thickness "a"
Out of specification→Replace as
a set.
2. Replace:
• Brake pad
Brake pad replacement steps:
a. Remove the protector "1" and pad
pin plug "2".
b. Loosen the pad pin "3".
c. Remove the rear wheel "4" and
brake caliper "5".
Refer to "FRONT WHEEL AND
REAR WHEEL" section in the
CHAPTER 6.d. Remove the pad pin "6" and brake
pads "7".
e. Connect the transparent hose "8"
to the bleed screw "9" and place
the suitable container under its
end.
f. Loosen the bleed screw and push
the brake caliper piston in.
Do not reuse the drained brake flu-
id.
g. Tighten the bleed screw.
h. Install the brake pad "10" and pad
pin "11".
• Install the brake pads with their pro-
jections "a" into the brake caliper re-
cesses "b".
• Temporarily tighten the pad pin at
this point.
i. Install the brake caliper "12" and
rear wheel "13".
Refer to "FRONT WHEEL AND
REAR WHEEL" section in the
CHAPTER 6.j. Tighten the pad pin "14".
k. Install the pad pin plug "15" and
protector "16".
3. Inspect:
• Brake fluid level
Refer to "CHECKING THE
BRAKE FLUID LEVEL" section.
4. Check:
• Brake pedal operation
A softy or spongy feeling→Bleed
brake system.
Refer to "BLEEDING THE HY-
DRAULIC BRAKE SYSTEM" sec-
tion.
CHECKING THE REAR BRAKE
PAD INSULATOR
1. Remove:
• Brake pad
Refer to "CHECKING AND RE-
PLACING THE REAR BRAKE
PADS" section.
2. Inspect:
• Rear brake pad insulator "1"
Damage→Replace. Brake pad thickness:
6.4 mm (0.25 in)
in)
Bleed screw:
6 Nm (0.6 m•kg, 4.3
ft•lb)
Pad pin:
18 Nm (1.8 m•kg, 13
ft•lb)
Pad pin plug:
3 Nm (0.3 m•kg, 2.2
ft•lb)
Bolt (protector):
7 Nm (0.7 m•kg, 5.1
ft•lb)

3-20
CHASSIS
CHECKING THE BRAKE FLUID
LEVEL
1. Place the brake master cylinder
so that its top is in a horizontal po-
sition.
2. Inspect:
• Brake fluid level
Fluid at lower level→Fill up.
• Use only designated quality
brake fluid to avoid poor brake
performance.
• Refill with same type and brand
of brake fluid; mixing fluids
could result in poor brake perfor-
mance.
• Be sure that water or other con-
taminants do not enter master
cylinder when refilling.
• Clean up spilled fluid immediate-
ly to avoid erosion of painted
surfaces or plastic parts.
a. Lower level
A. Front
B. Rear
CHECKING THE SPROCKET
1. Inspect:
• Sprocket teeth "a"
Excessive wear→Replace.
Replace the drive sprocket, rear
wheel sprocket and drive chain as a
set.
CHECKING THE DRIVE CHAIN
1. Measure:
• Drive chain length (15 links) "a"
Out of specification→Replace.
• While measuring the drive chain
length, push down on the drive
chain to increase its tension.
• Measure the length between drive
chain roller "1" and "16" as shown.
• Perform this measurement at two or
three different places.
2. Remove:
• Drive chain "1"
Remove the drive chain using a drive
chain cutter "2".
3. Clean:
• Drive chain
Brush off as much dirt as possi-
ble. Then clean the drive chain
using the chain cleaner.
This machine has a drive chain
with small rubber O-rings "1" be-
tween the side plates. Steam
cleaning, high-pressure washes,
certain solvent and kerosene can
damage these O-rings.
4. Inspect:
• O-ring "1" (drive chain)
Damage→Replace the drive
chain.
•Roller "2"
• Side plate "3"
Damage/wear→Replace the
drive chain.
5. Check:
• Drive chain stiffness "a"
Clean and oil the drive chain and
hold as illustrated.
Stiff→Replace the drive chain.
6. Install:
• Chain joint "1"
• O-ring "2"
• Drive chain "3"
• Link plate "4"
When installing the drive chain, apply
the lithium soap base grease on the
chain joint and O-rings.
7. Install:
• Link plate
• Press the link plate onto the chain
joint using a drive chain riveter "5".
• Rivet the end of the chain joint us-
ing a drive chain riveter.
• After riveting the chain joint, make
sure its movement is smooth.
Recommended brake flu-
id:
DOT #4
Drive chain length (15
links):
(9.42 in)

3-21
CHASSIS
8. Lubricate:
• Drive chain
ADJUSTING THE DRIVE CHAIN
SLACK
1. Elevate the rear wheel by placing
the suitable stand under the en-
gine.
2. Check:
• Drive chain slack "a"
Above the seal guard installation
bolt.
Out of specification→Adjust.
Before checking and/or adjusting, ro-
tate the rear wheel through several
revolutions and check the slack sev-
eral times to find the tightest point.
Check and/or adjust the drive chain
slack with the rear wheel in this "tight
chain" position.
3. Adjust:
• Drive chain slack
Drive chain slack adjustment
steps:
a. Loosen the axle nut "1" and lock-
nuts "2".b. Adjust the drive chain slack by
turning the adjusters "3".
c. Turn each adjuster exactly the
same amount to maintain correct
axle alignment. (There are marks
"a" on each side of the drive chain
puller alignment.) NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle and can lead to chain slip-
page or breakage. To prevent
this from occurring, keep the
drive chain slack within the
specified limits.
Turn the adjuster so that the drive
chain is in line with the sprocket, as
viewed from the rear.
d. Tighten the axle nut while pushing
down the drive chain.
e. Tighten the locknuts.
CHECKING THE FRONT FORK
1. Inspect:
• Front fork smooth action
Operate the front brake and
stroke the front fork.
Unsmooth action/oil leakage→
Repair or replace.CLEANING THE FRONT FORK OIL
SEAL AND DUST SEAL
1. Remove:
•Protector
• Dust seal "1"
Use a thin screw driver, and be care-
ful not to damage the inner fork tube
and dust seal.
2. Clean:
• Dust seal "a"
• Oil seal "b"
• Clean the dust seal and oil seal af-
ter every run.
• Apply the lithium soap base grease
on the inner tube.
RELIEVING THE FRONT FORK
INTERNAL PRESSURE
If the front fork initial movement feels
stiff during a run, relieve the front fork
internal pressure.
1. Elevate the front wheel by placing
a suitable stand under the engine.
2. Remove the air bleed screw "1"
and release the internal pressure
from the front fork.
3. Install:
• Air bleed screw Drive chain lubricant:
SAE 10W-40 motor oil
or suitable chain lubri-
cants
Drive chain slack:
48.0–58.0 mm (1.89–
2.28 in)
To tighten→Turn the adjuster "3"
counterclockwise.
To loosen→Turn the adjuster "3"
clockwise and push wheel for-
ward.
Axle nut:
125 Nm (12.5 m•kg, 90
ft•lb)
Locknut:
19 Nm (1.9 m•kg, 13
ft•lb)
Air bleed screw:
1 Nm (0.1 m•kg, 0.7
ft•lb)