
2 - 14
SPECMAINTENANCE SPECIFICATIONS
Wheel:
Front wheel type Spoke wheel ----
Rear wheel type Spoke wheel ----
Front rim size/material 21 ´ 1.60/Aluminum ----
Rear rim size/material 18 ´ 2.15/Aluminum ----
Rim runout limit
Radial ---- 2.0 mm (0.08 in)
Lateral ---- 2.0 mm (0.08 in)
Drive chain:
Type/manufacturer 520VM/DAIDO ----
Number of links 113 links + joint ----
Chain slack 40 ~ 50 mm (1.6 ~ 2.0 in) ----
Chain length (10 links) ----150.1 mm (5.91 in)
Front disc brake:
Disc outside diameter ´ Thickness 245 ´ 3.0 mm (9.65 ´ 0.12 in) 245 ´ 2.5 mm
(9.65 ´ 0.08 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 4.4 mm (0.17 in) 1 mm (0.04 in)
Master cylinder inside dia. 11.0 mm (0.433 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 2 ----
Brake fluid type DOT #4 ----
Rear disc brake:
Disc outside diameter ´ Thickness 240 ´ 4.0 mm (9.45 ´ 0.16 in) 240 ´ 3.5 mm
(9.45 ´ 0.14 in)
Deflection limit ----0.15 mm (0.006 in)
Pad thickness 6.4 mm (0.25 in) 1.0 mm (0.04 in)
Master cylinder inside dia. 14.0 mm (0.551 in) ----
Caliper cylinder inside dia. 27.0 mm (1.063 in) ´ 1 ----
Brake fluid type DOT #4 ----
Brake lever and brake pedal:
Brake lever position 82.5 mm (3.25 in) ----
Brake pedal height
(vertical height below footrest top)5 mm (0.20 in) ----
Clutch lever free play (at lever pivot) 2 ~ 4 mm (0.08 ~ 0.16 in) ----
Throttle grip free play 3 ~ 5 mm (0.12 ~ 0.20 in) ----Item Standard Limit

2 - 15
SPECMAINTENANCE SPECIFICATIONS
HINWEIS:NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench, then loosen the ring nut one turn.
2. Retighten the ring 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
Handle crown and outer tube M8 ´ 1.25 4 23 2.3 17
Under bracket and outer tube M8 ´ 1.25 4 20 2.0 14
Handle crown and steering shaft M24 ´ 1.0 1 145 14.5 105
Handlebar holder (upper) M8 ´ 1.25 4 23 2.3 17
Steering ring nut M28 ´ 1.0 1 Refer to NOTE.
Front fork and cap bolt M48 ´ 1.0 2 30 3.0 22
Front fork and base valve M30 ´ 1.0 2 55 5.5 40
Cap bolt and damper rod (front fork) M12 ´ 1.25 2 29 2.9 21
Bleed screw (front fork) and cap bolt M5 ´ 0.8 2 1 0.1 0.7
Front fork and protector M6 ´ 1.0 6 10 1.0 7.2
Front fork and brake hose holder M6 ´ 1.0 2 10 1.0 7.2
Front fork and hose cover M8 ´ 1.25 1 16 1.6 11
Front fork and hose cover M6 ´ 1.0 1 7 0.7 5.1
Throttle cable cap M5 ´ 0.8 2 4 0.4 2.9
Clutch lever holder M5 ´ 0.8 2 4 0.4 2.9
Decompression lever holder M5 ´ 0.8 2 4 0.4 2.9
Front brake master cylinder and bracket M6 ´ 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 ´ 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 ´ 1.0 1 7 0.7 5.1
Brake lever mounting (nut) M6 ´ 1.0 1 7 0.7 5.1
Brake lever position locknut M6 ´ 1.0 2 7 0.7 5.1
Cable guide (front brake hose) and guide stay M5 ´ 0.8 1 4 0.4 2.9
Front brake hose union bolt (master cylinder)M10 ´ 1.25 1 30 3.0 22
Front brake hose union bolt (caliper) M10 ´ 1.25 1 30 3.0 22
Front brake caliper and front fork M8 ´ 1.25 2 23 2.3 17
Brake caliper (front and rear) and pad pin M10 ´ 1.0 1 18 1.8 13
Brake caliper (front and rear) and pad pin plug M10 ´ 1.0 1 3 0.3 2.2
Brake caliper (front and rear) and bleed screw M8 ´ 1.25 1 6 0.6 4.3
Front wheel axle and nut M16 ´ 1.5 1 105 10.5 75
Front wheel axle holder M8 ´ 1.25 4 23 2.3 17
Front brake disc and wheel hub M6 ´ 1.0 6 12 1.2 8.7
Rear brake disc and wheel hub M6 ´ 1.0 6 14 1.4 10
Brake pedal mounting M8 ´ 1.25 1 19 1.9 13
Rear brake master cylinder and frame M6 ´ 1.0 2 10 1.0 7.2

2 - 21
SPEC
CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1
Hose guide
2
Brake hose
3
Regulator
4
Fuel tank breather hose
5
Oil tank breather hose
6
Clamp
7
“ENGINE STOP” button lead
8
Sub wire harness
9
Tail light lead
0
TPS (throttle position sensor) lead
A
Neutral switch lead
B
Oil hose
C
Cylinder head breather hose
D
CDI magneto lead
E
Hose holder
F
Clutch cable
G
Decompression cable
H
Lights switch lead
I
Carburetor breather hose
J
Overflow hose
K
Coolant reservoir tank breather hose
Pass the fuel tank breather
hose behind handlebar, then
insert it into the steering shaft
hole.
õ
Pass the decompression
cable, “ENGINE STOP” but-
ton lead and lights switch lead
under where the oil hose is
attached.
‚
Pass the “ENGINE STOP” but-
ton lead, regulator lead and
lights switch lead along the
inner and side of the decom-
pression cable.
ë
Fasten the CDI magneto lead,
neutral switch lead “ENGINE
STOP” button lead and lights
switch lead to the frame with a
plastic locking tie.äPass the “ENGINE STOP”
button lead and lights switch
lead along the inner side of
the oil tank breather hose.
ìFasten the sub wire harness,
“ENGINE STOP” button lead
and lights switch lead to the
frame with a plastic locking
tie.
íPass the cylinder head
breather hose along the right
side of the oil tank breather
hose.
îFasten the sub wire harness
to the frame with a plastic
locking tie and cut off the tie
end.
éFasten the TPS lead (in the
sub wire harness) under the
frame.

2 - 22
SPECCABLE ROUTING DIAGRAM
ïFasten the TPS lead under the
coupler to the frame with a
plastic locking tie.
ðPass the carburetor breather
hose and overflow hose
between the connecting rod
and cross tube (frame).
ñFasten the neutral switch lead
and oil hose together with a
plastic locking tie.
÷Fasten the neutral switch lead
to the frame with a plastic
band.
öFasten the cylinder head
breather hose with the hose
holder.
¯Fasten the neutral switch lead
and CDI magneto lead
together with a plastic band.
¸Pass the clutch cable through
the cable guide.ÎPass the cylinder head
breather hose along the inner
side of the radiator pipe.
åPass the clutch cable between
the frame and radiator and
over the lower boss on the
radiator.
êPass the neutral switch lead
and CDI magneto lead over
the middle radiator mounting
boss. Then, pass the decom-
pression cable under the mid-
dle radiator mounting boss
and along the left side of the
neutral switch lead and CDI
magneto lead.
æPass the clutch cable through
the cable guide.
èFit the brake hose into the
guide on the protector.×Fasten the ignition coil lead
(in the sub wire harness) on
the upper inside of the frame
and cut off the tie end.
ãPass the ignition coil lead (in
the sub wire harness) under
the cushion bracket (frame).
ÅFasten the ignition coil lead
(in the sub wire harness) to
the frame with a plastic lock-
ing tie and cut off the tie end.
çPass the carburetor breather
hoses and overflow hose so
that all there hoses do not
contact the rear shock
absorber.

2 - 24
SPECCABLE ROUTING DIAGRAM
1Throttle cable
2Lights switch
3Lights switch lead
4Clamp
5Decompression cable
6Clutch cable
7Hose guide
8Trip meter
9Brake hose
0“ENGINE STOP” button leadFasten the “ENGINE STOP” button lead to the handlebar with the
plastic band.
õPass the decompression cable between the brake hose and clutch
cable.
‚Pass the throttle cables between the handle crown and trip meter.
ëPass the light switch leads behind the “ENGINE STOP” button lead,
then pass the head light lead (of the light switch leads) in front of the
head pipe.
äInstall the trip meter cable so that its bent portion faces the chassis
rear.
ìInstall the brake hose so that it contacts the master cylinder projec-
tion and that its bent portion faces downward.

3 - 1
INSP
ADJ
MAINTENANCE INTERVALS
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
EC310022
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
cc
OIL FILTER
Replace
cc
VALVES
Check the valve clearances.
Inspect
Replace
cc
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.
CAMSHAFT SPROCKETS
Inspect
Replace
c
c
Check for wear on the
teeth and for damage.
PISTON
Inspect
Clean
Replace
cc
c
c
Inspect crack
Remove carbon
PISTON RING
Inspect
Replace
c
cc
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
cc
c
Inspect housing, friction
plate, clutch plate and
spring
TRANSMISSION
Inspect
Replace bearing
c
c
3

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 filler cap.
Check that the coolant level is correct in the coolant reservoir
tank.
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.1-12
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
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated 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.—
Muffler Check that the muffler is tightly mounted and has no cracks. P.4-2
Sprocket Check that the driven 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.1-17
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-5
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 ~ 21

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
lRadiator hose joint
Coolant leakage ® Repair or replace.
lRadiator hose
Swelling ® Replace.
EC359001
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 3.
lAfter adjustment, check proper operation of
clutch lever. Clutch lever free play adjustment steps:
lLoosen the locknut 1.
lTurn the adjuster 2 until free play a is
within the specified limits.
lTighten the locknut.