CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
EXHAUST PIPE AND SILENCER
............ 4-2
RADIATOR
............................................... 4-4
CARBURETOR
......................................... 4-7
CAMSHAFTS
.......................................... 4-19
CYLINDER HEAD
................................... 4-28
VALVES AND VALVE SPRINGS
........... 4-32
CYLINDER AND PISTON
....................... 4-41
CLUTCH
.................................................. 4-48
OIL FILTER ELEMENT,
WATER PUMP AND RIGHT
CRANKCASE COVER
............................ 4-55
BALANCER
............................................ 4-62
OIL PUMP
............................................... 4-65
KICK SHAFT AND SHIFT SHAFT
......... 4-70
CDI MAGNETO
....................................... 4-77
ENGINE REMOVAL
................................ 4-81
CRANKCASE AND CRANKSHAFT
....... 4-86
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
.................................. 4-95
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT BRAKE AND REAR BRAKE
.... 5-10
FRONT FORK
......................................... 5-27
HANDLEBAR
.......................................... 5-40
STEERING
.............................................. 5-45
SWINGARM
............................................ 5-50
REAR SHOCK ABSORBER
................... 5-57
GEN
INFO
1 - 1
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1
Clutch lever
2
Decompression lever
3
Front brake lever
4
Throttle grip
5
Radiator cap
6
Fuel tank cap
7
Oil tank cap
8
Engine stop switch
9
Kickstarter crank
0
Fuel tank
A
Radiator
B
Coolant drain bolt
C
Rear brake pedal
D
Valve joint
E
Fuel cock
F
Cold starter knob
G
Hot starter knob (red)
H
Drive chain
I
Air filter
J
Shift pedal
K
Front fork
NOTE:
l
The machine you have purchased may differ
slightly from those shown in the following.
l
Designs and specifications are subject to
change without notice.
1
SPEC
2 - 2
GENERAL SPECIFICATIONS
Oil capacity:
Engine oil
Periodic oil change 1.5 L (1.32 Imp qt, 1.59 US qt)
With oil filter replacement 1.6 L (1.41 Imp qt, 1.69 US qt)
Total amount 1.7 L (1.50 Imp qt, 1.80 US qt)
Coolant capacity (including all routes): 0.9 L (0.79 Imp qt, 0.95 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded fuel with a research octane
number of 95 or higher. (Except for AUS)
Unleaded fuel only (For AUS)
Tank capacity 8.0 L (1.76 Imp gal, 2.11 US gal)
Carburetor:
Type FCR-MX37
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK
U24ESR-N/DENSO
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 57/17 (3.353)
Secondary reduction system Chain drive
Secondary reduction ratio 48/13 (3.692)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 30/14 (2.143)
2nd 28/16 (1.750)
3rd 29/20 (1.450)
4th 27/22 (1.227)
5th 25/24 (1.042)
Chassis:
Frame type Semi double cradle
Caster angle 27.1˚
Trail 117.4 mm (4.62 in)
Tire:
Type With tube
Size (front) 80/100-21 51M (For USA, CDN, ZA, AUS, NZ
and F)
80/100-21 MT320 (For EUROPE except F)
Size (rear) 100/90-19 57M (For USA, CDN, ZA, AUS, NZ
and F)
100/90-19 MT320 (For EUROPE except F)
Tire pressure (front and rear) 100 kPa (1.0 kg/cm
2
, 15 psi)
2
SPEC
2 - 9
MAINTENANCE SPECIFICATIONS
Lubrication system:
Oil filter type Wire mesh type ----
Oil pump type Trochoid type ----
Tip clearance 0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Side clearance 0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Housing and rotor clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.0067 in)
Cooling:
Radiator core size
Width 107.8 mm (4.2 in) ----
Height 220 mm (8.7 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure110 kPa (1.1 kg/cm
2
, 15.6 psi)----
Radiator capacity (total) 0.56 L (0.49 lmp qt, 0.59 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
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
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
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
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
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
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
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks
3
3 - 13
INSP
ADJ
ENGINE OIL LEVEL INSPECTION
3. Inspect:
lAir filter element
Damage ® Replace.
4. Apply:
lFoam-air-filter oil or engine oil to the ele-
ment.
NOTE:
Squeeze out the excess oil. Element should
be wet but not dripping.
5. Install:
lAir filter guide 1
NOTE:
Align the projection a on air filter guide with
the hole b in air filter element.
6. Apply:
lLithium soap base grease
On the matching surface a on air filter
element.
7. Install:
lAir filter element 1
lWasher
lFitting bolt
NOTE:
Align the projection a on filter guide with the
hole b in air filter case.
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
ENGINE OIL LEVEL INSPECTION
1. Start the engine, warm it up for several
minutes, and then turn off the engine and
wait for five minutes.
2. Place the machine on a level place and
hold it up on upright position by placing
the suitable stand under the engine.