GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Steering nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-1423, 90890-01423 Damper rod holder
Use this tool to remove and install the damper rod.YM-1423 90890-01423
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YU-3112-C, 90890-03112 Pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YU-08036-B
90890-03113Inductive tachometer
Engine tachometer
This tool is needed for observing engine rpm.YU-08036-B 90890-03113
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-04019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-04019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-4111, 90890-04111
YM-4116, 90890-04116Valve guide remover
Intake 4.0 mm (0.16 in)
Exhaust 4.5 mm (0.18 in)
This tool is needed to remove and install the valve
guide.YM-4111
YM-411690890-04111
90890-04116
Part number Tool name/How to use Illustration
SPEC
2 - 10
MAINTENANCE SPECIFICATIONS
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S
´
1.0 1 13 1.3 9.4
Camshaft cap M6
´
1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12
´
1.0 1 37 3.7 27
Cylinder head (stud bolt) M6
´
1.0 2 7 0.7 5.1
(stud bolt) M8
´
1.25 1 15 1.5 11
(bolt) M9
´
1.25 4 38 3.8 27
(nut) M6
´
1.0 2 10 1.0 7.2
Cylinder head cover M6
´
1.0 2 10 1.0 7.2
Oil pressure check bolt M6
´
1.0 1 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
Decompression shaft M6
´
1.0 1 7 0.7 5.1
Decompression cable guide M6
´
1.0 1 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 8 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 M6
´
1.0 6 10 1.0 7.2
Radiator guard M6
´
1.0 2 10 1.0 7.2
Radiator pipe M6
´
1.0 1 10 1.0 7.2
Oil pump cover M4
´
0.7 1 3 0.3 2.2
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 M6
´
1.0 2 10 1.0 7.2
Oil delivery pipe 1 (M10) M10 ´ 1.25 1 20 2.0 14
(M8) M8 ´ 1.25 2 18 1.8 13
Oil delivery pipe 2 M6 ´ 1.0 1 10 1.0 7.2
Oil hose M6 ´ 1.0 3 10 1.0 7.2
Oil hose clamp — 2 2 0.2 1.4
Oil strainer and frame M18 ´ 1.5 1 90 9.0 65
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 cover M5 ´ 0.8 1 4 0.4 2.9
Air filter joint M5 ´ 0.8 2 5 0.5 3.6
Air filter joint and air filter case M5 ´ 0.8 5 1 0.1 0.7
Air filter element M6 ´ 1.0 1 2 0.2 1.4
Air filter case cover M6 ´ 1.0 4 4 0.4 2.9
Exhaust pipe (nut) M8 ´ 1.25 1 13 1.3 9.4
(bolt) M8 ´ 1.25 1 24 2.4 17
Exhaust pipe protector M6 ´ 1.0 3 10 1.0 7.2
SPEC
2 - 11
MAINTENANCE SPECIFICATIONS
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race. Silencer M8 ´ 1.25 2 35 3.5 25
Silencer clamp M8 ´ 1.25 1 20 2.0 14
Spark arrester (for USA) M6 ´ 1.0 3 10 1.0 7.2
Silencer end pipe (for USA) M6 ´ 1.0 1 10 1.0 7.2
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 10 1.0 7.2
Left crankcase cover M6 ´ 1.0 8 10 1.0 7.2
Right crankcase cover M6 ´ 1.0 8 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
Drive chain sprocket cover M6 ´ 1.0 2 10 1.0 7.2
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 8 0.8 5.8
Clutch boss M16 ´ 1.0 1 60 6.0 43
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 Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
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 race
or
500 km
(300 mi)Every
fifth race
or
1,000 km
(600 mi)
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
3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
c
Inspect wear
ROTOR NUT
Retighten
c
c
EXHAUST PIPE, SILENCER, PRO-
TECTOR
Inspect and retighten
Clean
Replace
c
c
c
c
* Whichever comes first
*SPARK ARRESTER
Clean
(Every six
months)
c
CRANK
Inspect and clean
c
c
CARBURETOR
Inspect, adjust and clean
c
c
When using a high-pres-
sure washer, make sure
that water does not enter
the accelerator pump.
SPARK PLUG
Inspect and clean
Replace
c
c
c
DRIVE CHAIN
Lubricate, slack, alignment
Replace
c
c
c
Use chain lube
Chain slack: 40 ~ 50 mm
(1.6 ~ 2.0 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
c
c
c
c
c
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
c
c
Refer to “STARTING
AND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
c
c
c
Use foam air-filter oil
FRAME
Clean and inspect
c
c
FUEL TANK, COCK
Clean and inspect
c
c
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper
bolts, master cylinder bolts and union
bolts
Replace pads
Replace brake fluid
c
c
c
c
c
c
c
c
c
c
c
c
Every one year
FRONT FORKS
Inspect and adjust
Replace oil
Replace oil seal
c
c
c
c
c
Suspension oil “01” ItemAfter
break-inEvery
race
Every
third race
or
500 km
(300 mi)Every
fifth race
or
1,000 km
(600 mi)
As re-
quiredRemarks
3
3 - 3
INSP
ADJ
MAINTENANCE INTERVALS
* marked : For USAFRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
c
c
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
c
c
c
c
c c Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
c c
SWINGARM
Inspect and retighten
c c
RELAY ARM, CONNECTING ROD
Inspect and lube
c c Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
c c
c
c Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
c
c
c
c
c
c
c
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
c
c
c
c Yamaha cable lube or
SAE 10W-30 motor oil ItemAfter
break-inEvery
race
Every
third race
or
500 km
(300 mi)Every
fifth race
or
1,000 km
(600 mi)
As re-
quiredRemarks
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 that the coolant level is correct in the coolant reservoir.
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.3-14 ~ 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.3-26 ~ 32
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-33 ~ 35
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-43 ~ 44
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-44 ~ 45
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-35 ~ 42
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.3-33
Lubrication Check for smooth operation. Lubricate if necessary. P.3-46
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
3 - 7
INSP
ADJ
RADIATOR CAP INSPECTION
CAUTION:
lDo not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
lDo not use water containing impurities or oil.
10. Install:
lRadiator cap
11. Fill:
lCoolant reservoir
Midway a between maximum and min-
imum marks on the tank.
12. Install:
lCoolant reservoir cap
13. Start the engine and let it warm up for
several minutes.
14. Turn off the engine and inspect the cool-
ant level.
Refer to “COOLANT LEVEL INSPEC-
TION” section.
NOTE:
Before checking the coolant level wait a few
minutes until the coolant settles.Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
lWhen coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
lWhen coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
lWhen coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
LOWFULLCOOLANTa
EC355000
RADIATOR CAP INSPECTION
1. Inspect:
lSeal (radiator cap) 1
lValve and valve seat 2
Crack/damage ® Replace.
Exist fur deposits 3 ® Clean or
replace.