Page 87 of 656

SPEC
2 - 14
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the steering nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the steering
nut wrench, then loosen the steering nut one turn.
2. Retighten the steering nut 7 Nm (0.7 m • kg, 5.1 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 23 2.3 17
Lower bracket and outer tube M8 ´ 1.25 4 20 2.0 14
Upper bracket and steering stem M24 ´ 1.0 1 145 14.5 105
Handlebar holder and upper bracket M8 ´ 1.25 4 28 2.8 20
Steering stem and steering ring nut M28 ´ 1.0 1 Refer to NOTE.
Front fork and front fork cap bolt M48 ´ 1.0 2 30 3.0 22
Front fork and base valve M30 ´ 1.0 2 55 5.5 40
Front fork cap bolt and damper rod M12 ´ 1.25 2 29 2.9 21
Front fork bleed screw and front fork cap bolt M5 ´ 0.8 2 1 0.1 0.7
Front fork and front fork protector M6 ´ 1.0 6 10 1.0 7.2
Front fork and brake hose guide M5 ´ 0.8 1 4 0.4 2.2
Front fork and brake hose holder M6 ´ 1.0 2 10 1.0 7.2
Front fork and brake hose cover (M8) M8 ´ 1.25 1 16 1.6 11
(M6) M6 ´ 1.0 1 7 0.7 5.1
Throttle grip cap M5 ´ 0.8 2 4 0.4 2.2
Front brake master cylinder M6 ´ 1.0 2 9 0.9 6.5
Brake lever mounting bolt M6 ´ 1.0 1 6 0.6 4.3
Brake lever mounting nut M6 ´ 1.0 1 6 0.6 4.3
Brake lever position locknut M6 ´ 1.0 1 5 0.5 3.6
Clutch lever holder M5 ´ 0.8 2 4 0.4 2.2
Clutch lever mounting bolt M6 ´ 1.0 1 2 0.2 1.4
Decompression lever holder M5 ´ 0.8 2 4 0.4 2.2
Front brake master cylinder cap M4 ´ 0.7 2 2 0.2 1.4
Front brake hose union bolt M10 ´ 1.25 2 30 3.0 22
Front brake caliper M8 ´ 1.25 2 23 2.3 17
Pad pin plug M10 ´ 1.0 2 3 0.3 2.2
Front brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Rear brake caliper and pad pin M10 ´ 1.0 1 18 1.8 13
Brake caliper and bleed screw M8 ´ 1.25 2 6 0.6 4.3
Front wheel axle and axle nut M16 ´ 1.5 1 105 10.5 75
Front wheel axle holder M8 ´ 1.25 4 23 2.3 17
Front brake disc M6 ´ 1.0 6 12 1.2 8.7
Rear brake disc M6 ´ 1.0 6 14 1.4 10
Brake pedal M8 ´ 1.25 1 26 2.6 19
Rear brake master cylinder M6 ´ 1.0 2 10 1.0 7.2
Rear brake reservoir tank M6 ´ 1.0 1 10 1.0 7.2
Rear brake reservoir tank cap M4 ´ 0.7 2 2 0.2 1.4
Rear brake hose union bolt M10 ´ 1.25 2 30 3.0 2.2
Rear wheel axle and axle nut M20 ´ 1.5 1 125 12.5 90
Page 142 of 656

2 - 18
SPEC
CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Hose guide
2
Brake hose
3
Fuel tank breather hose
4
Engine stop switch lead
5
Oil tank breather hose
6
Sub-wire harness
7
Neutral switch lead
8
Cable guide
9
Cylinder head breather hose
0
CDI magneto lead
A
Radiator breather hose
B
Carburetor breather hose
C
Carburetor overflow hose
D
Ignition coil lead
E
CDI unit lead
Pass the fuel tank breather hose
between the handlebar and ten-
sion bar, then insert its end into
the hole of the number plate.
õ
Fasten the engine stop switch
lead and ignition coil lead of the
sub-wire harness.
‚
Fasten the sub-wire harness
and engine stop switch lead.
Fasten the engine stop switch
lead at its protecting tube.
ë
Fasten the sub-wire harness
and engine stop switch leads.
ä
Pass the sub-wire harness
between upper engine brackets.
ì
Fasten the sub-wire harness.
í
Fasten the throttle position sen-
sor lead.
î
Pass the carburetor breather
hose and overflow hose
between the connecting rod and
cross tube (frame).
é
Fasten the neutral switch lead
on the oil hose.
ï
Pass the clutch cable through
the cable guide.
ð
Fasten the cylinder head
breather hose and neutral switch
lead.
ñ
Fasten the neutral switch lead.
Page 144 of 656
2 - 19
SPEC
CABLE ROUTING DIAGRAM
÷
Pass the cylinder head
breather hose through the hose
guide.
ö
Fasten the neutral switch lead
and CDI magneto lead.
¯
Pass the clutch cable on the
inside the cylinder head
breather hose.
¸
Pass the clutch cable in front of
the radiator mounting boss.
Î
Fit the brake hose into the
guides on the protector.
å
Pass the carburetor breather
hoses and overflow hose so
that all there hoses do not con-
tact the rear shock absorber.
ê
Fasten the ground lead
together with the ignition coil.
æ
Do not allow the engine stop
switch leads to slacken
between the two clamps.
è
Pass the clutch cable through
the cable guides.
Ã
Position each lead at the lower
left of the main tube (frame).
Page 150 of 656
2 - 22
SPECCABLE ROUTING DIAGRAM
1Throttle cable
2Clamp
3Decompression cable
4Clutch cable
5Brake hose
6Hose guide
7Engine stop switch leadFasten the engine stop switch lead to the handlebar with the plastic
band.
õPass the brake hose in front of the number plate.
Page 152 of 656

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
MAINTENANCE INTERVALS
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.
ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks
ENGINE OIL
Replace
Inspect
c
cc
c
OIL FILTER ELEMENT, OIL STRAINER
Clean
c
VALVES
Check the valve clearances.
Inspect
Replace
c
c
c
c
The engine must be cold.
Check the valve seats
and valve stems for wear.
VALVE SPRINGS
Inspect
Replace
c
c
Check the free length and
the tilt.
VALVE LIFTERS
Inspect
Replace
c
c
Check for scratches and
wear.
CAMSHAFTS
Inspect
Replace
c
c
Inspect the camshaft sur-
face.
TIMING CHAIN SPROCKETS, TIMING
CHAIN
Inspect
Replace
c
c
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
c
c
c
c
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
c
c
c
Check ring end gap
PISTON PIN
Inspect
Replace
c
c
CYLINDER HEAD
Inspect and clean
c
Remove carbon
Change gasket
CYLINDER
Inspect and clean
Replace
c
c
Inspect score marks
Inspect wear
CLUTCH
Inspect and adjust
Replace
c
c
c
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
c
c
3
Page 164 of 656

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, 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 cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-13 ~ 17
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck 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 effect of front and rear brake. P.3-25 ~ 31
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-32 ~ 34
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-42 ~ 43
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-43 ~ 44
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-34 ~ 41
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 pipeCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-2
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-32
Lubrication Check for smooth operation. Lubricate if necessary. P.3-45
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 22
Page 176 of 656
3 - 9
INSP
ADJ
CLUTCH ADJUSTMENT
NOTE:
lDo not apply pressure more than specified
pressure.
lRadiator should be filled fully.
4. Inspect:
lPressure
Impossible to maintain the specified
pressure for 10 seconds ® Repair.
lRadiator 1
lRadiator hose joint 2
Coolant leakage ® Repair or replace.
lRadiator hose 3
Swelling ® Replace.
CLUTCH ADJUSTMENT
1. Check:
lClutch lever free play a
Out of specification ® Adjust.
Clutch lever free play a:
2 ~ 4 mm (0.08 ~ 0.16 in)
2. Adjust:
lClutch lever free play
NOTE:
lMake minute adjustment on the lever side
using the adjuster 2.
lAfter adjustment, check proper operation of
clutch lever. Clutch lever free play adjustment steps:
lLoosen the locknuts 1.
lAdjust the free play by changing their
tightening position.
lTighten the locknuts.
Page 186 of 656
3 - 14
INSP
ADJ
3. Remove:
lOil tank cap 1
4. Inspect:
lOil level
Oil level should be between maximum
a and minimum b marks.
Oil level is low ® Add oil to proper
level.
NOTE:
When inspecting the oil level, do not screw the
oil tank cap into the oil tank. Insert the gauge
lightly.
(For USA and CDN)
CAUTION:
lDo not add any chemical additives.
Engine oil also lubricates the clutch and
additives could cause clutch slippage.
lDo not allow foreign material to enter the
crankcase.
Recommended oil:
At 5 ˚C (40 ˚F) or higher
Yamalube 4 (20W-40) or SAE
20W-40 type SH motor oil (Non-
Friction modified)
At 15 ˚C (60 ˚F) or lower õ
Yamalube 4 (10W-30) or SAE
10W-30 type SH motor oil (Non-
Friction modified)
and/or
Yamalube 4-R (15W-50)
(Non-Friction modified)
ENGINE OIL LEVEL INSPECTION