2003 YAMAHA WR 450F oil filter

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
................................. 4-1
EXHAUST PIPE AND SILENCER
............ 4-3
RADIATOR
................................................ 4-5
CARBURETOR
......................................... 4-8
CAMSHAFTS
.......................................... 4-21
CYLINDER HEAD
................................... 4-29
VALVES AND VALVE SPRINGS
........... 4-33
CYLINDER AND PISTON
....................... 4-42
CLUTCH
.................................................. 4-48
OIL FILTER, WATER PUMP
AND CRANKCASE COVER (RIGHT)
.... 4-55
BALANCER
............................................ 4-62
OIL PUMP
............................................... 4-65
KICK AXLE AND SHIFT SHAFT
............ 4-69
AC MAGNETO
AND STARTER CLUTCH
....................... 4-76
ENGINE REMOVAL
................................ 4-83
CRANKCASE AND CRANKSHAFT
....... 4-89
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
.................................. 4-98
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
...... 5-1
FRONT BRAKE AND REAR BRAKE
..... 5-11
FRONT FORK
......................................... 5-27
HANDLEBAR
.......................................... 5-40
STEERING
.............................................. 5-46
SWINGARM
............................................ 5-52
REAR SHOCK ABSORBER
................... 5-60

1 - 15
GEN
INFO
STARTING AND BREAK-IN
STARTING AND BREAK-IN
WARNING
Never start or run the engine in a closed
area. The exhaust fumes are poisonous;
they can cause loss of consciousness and
death in a very short time. Always operate
the machine in a well-ventilated area.
CAUTION:
The carburetor on this machine has a
built-in accelerator pump. Therefore,
when starting the engine, do not operate
the throttle or the spark plug will foul.
Unlike a two-stroke engine, this engine
cannot be kick started when the throttle is
open because the kickstarter may kick
back. Also, if the throttle is open the air/
fuel mixture may be too lean for the
engine to start.
Before starting the machine, perform the
checks in the pre-operation check list.
AIR FILTER MAINTENANCE
According to “AIR FILTER CLEANING” section
in the CHAPTER 3, apply the foam-air-filter oil
or its equivalent to the element. (Excess oil in
the element may adversely affect engine start-
ing.)
STARTING A COLD ENGINE
NOTE:
This model is equipped with an ignition circuit
cut-off system. The engine can be started
under the following conditions.
When the transmission is in neutral.
When the clutch is disengaged with the
transmission in any position. However, it is
recommended to shift into neutral before
starting the engine.
1. Inspect the coolant level.
2. Turn the fuel cock to “ON”.
3. Push the main switch to “ON”.
4. Shift the transmission into neutral.
5. Fully open the cold starter knob 1.
6. Start the engine by pushing the start
switch or by kicking the kickstarter.

SPEC

2 - 2
GENERAL SPECIFICATIONS
Oil capacity:
Engine oil
Periodic oil change 1.0 L (0.88 Imp qt, 1.06 US qt)
With oil filter replacement 1.1 L (0.97 Imp qt, 1.16 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 1.6 L (1.41 Imp qt, 1.69 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a research
octane number of 95 or higher.(Except for ZA)
Premium gasoline (For ZA)
Tank capacity 10 L (2.2 Imp gal, 2.64 US gal)
Reserve 1.2 L (0.26 Imp gal, 0.32 US gal)
Carburetor:
Type FCR MX39
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
Transmission:
Primary reduction system Gear
Primary reduction ratio 62/22 (2.818)
Secondary reduction system Chain drive
Secondary reduction ratio 50/14 (3.571)
Transmission type Constant mesh, 5-speed
Operation Left foot operation
Gear ratio: 1st 29/12 (2.416)
2nd 26/15 (1.733)
3rd 21/16 (1.312)
4th 21/20 (1.050)
5th 21/25 (0.840)
Chassis:
Frame type Semi double cradle
Caster angle 27.2˚
Trail 118 mm (4.65 in)
Tire:
Type With tube
Size (front) 80/100-21 51M (USA, CDN, ZA)
90/90-21 54R (EUROPE, AUS, NZ)
Size (rear) 110/100-18 64M (USA, CDN, ZA)
130/90-18 69R (EUROPE, AUS, NZ)
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2

, 15 psi)

2

SPEC

2 - 7
MAINTENANCE SPECIFICATIONS
Piston rings:
Top ring:
Type Barrel ----
Dimensions (B
×
T) 1.2
×
3.5 mm (0.05
×
0.14 in) ----
End gap (installed) 0.20 ~ 0.30 mm
(0.008 ~ 0.012 in)0.55 mm
(0.022 in)
Side clearance (installed) 0.030 ~ 0.065 mm
(0.0012 ~ 0.0026 in)0.12 mm
(0.005 in)
2nd ring:
Type Taper ----
Dimensions (B
×
T) 1.00
×
3.35 mm (0.04
×
0.13 in) ----
End gap (installed) 0.35 ~ 0.50 mm
(0.014 ~ 0.020 in)0.85 mm
(0.033 in)
Side clearance 0.020 ~ 0.055 mm
(0.0008 ~ 0.0022 in)0.12 mm
(0.005 in)
Oil ring:
Dimensions (B
×
T) 2.0
×
2.9 mm (0.08
×
0.11 in) ----
End gap (installed) 0.2 ~ 0.5 mm (0.01 ~ 0.02 in) ----
Crankshaft:
Crank width “A”61.95 ~ 62.00 mm
(2.439 ~ 2.441 in)----
Runout limit “C”0.03 mm (0.0012 in) 0.05 mm
(0.002 in)
Big end side clearance “D”0.15 ~ 0.45 mm
(0.0059 ~ 0.0177 in)0.50 mm
(0.02 in)
Small end free play “F”0.4 ~ 1.0 mm (0.02 ~ 0.04 in) 2.0 mm
(0.08 in)
Balancer:
Balancer drive method Gear ----
Air filter oil grade: Foam-air-filter oil or equivalent oil ----Item Standard Limit
T
B
B
T
B
T

SPEC

2 - 9
MAINTENANCE SPECIFICATIONS
Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance “A”0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Tip clearance “B”0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Side clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.007 in)
Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm
2

,
5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width 127.8 mm (5.0 in) ----
Height 260 mm (10.2 in) ----
Thickness 32 mm (1.26 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2

, 15.6 psi) ----
Radiator capacity (total) 0.78 L (0.69 Imp qt, 0.82 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit

SPEC

2 - 10
MAINTENANCE SPECIFICATIONS
Item Standard
Lubrication chart:
Pressure feed
Splashed scavenge
Oil strainer
Oil pan Oil pump rotor 2
Oil pump rotor 1
Oil tank
Oil filter
Check ball
Cylinder head
Crank pinPiston pinPiston
Drive axleMain axleTransmission gears
Camshaft
Valve lifter

SPEC

2 - 11
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
M8
×
1.25 1 15 1.5 11
(bolt) M10
×
1.25 4 Refer to NOTE.*
1

(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
Timing chain tensioner M6
×
1.0 2 10 1.0 7.2
Tensioner cap bolt M6
×
1.0 1 7 0.7 5.1
Timing chain guide (rear) M6
×
1.0 2 10 1.0 7.2
Exhaust pipe (nut) M8
×
1.25 1 13 1.3 9.4
(bolt) M8
×
1.25 1 24 2.4 17
Silencer M8
×
1.25 2 35 3.5 25
Silencer clamp M8
×
1.25 1 20 2.0 14
Exhaust pipe protector M6
×
1.0 3 10 1.0 7.2
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
Carburetor joint clamp (cylinder head side) M5
×
0.8 1 3 0.3 2.2
Carburetor joint clamp (carburetor side) M4
×
0.7 1 3 0.3 2.2
Air filter case M6
×
1.0 2 8 0.8 5.8
Air filter joint clamp M6
×
1.0 1 3 0.3 2.2
Air filter joint and air filter case M5
×
0.8 1 4 0.4 2.9
Throttle cable (pull) M6
×
1.0 1 4 0.4 2.9
Throttle cable (return) M12
×
1.0 1 11 1.1 8.0
Throttle cable cover M5
×
0.8 2 4 0.4 2.9
Hot starter plunger M12
×
1.0 1 2 0.2 1.4
Radiator panel (upper) M6
×
1.0 2 10 1.0 7.2
Radiator M6
×
1.0 6 10 1.0 7.2
Radiator hose clamp M6
×
1.0 8 2 0.2 1.4
Radiator pipe 1, 2 M10
×
1.0 2 10 1.0 7.2
Impeller M8
×
1.25 1 14 1.4 10
Water pump housing cover M6
×
1.0 3 10 1.0 7.2
Coolant drain bolt M6
×
1.0 1 10 1.0 7.2
Oil pump cover M4
×
0.7 1 2 0.2 1.4
Oil pump M6
× 1.0 3 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 × 1.0 1 10 1.0 7.2
Oil filter cover M6 × 1.0 2 10 1.0 7.2
Oil delivery pipe 1 M10 × 1.25 1 20 2.0 14
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 2 10 1.0 7.2

3 - 2
INSP
ADJ

MAINTENANCE INTERVALS
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
●
Inspect wear
ROTOR NUT
Retighten
●

●

MUFFLER
Inspect and retighten
Clean
Replace
●

●

●

●
* Whichever comes first
*SPARK ARRESTER
Clean
(Every
six
months)
●
CRANK
Inspect and clean
●

●

CARBURETOR
Inspect, adjust and clean
●

●

SPARK PLUG
Inspect and clean
Replace
●

●

●

DRIVE CHAIN
Lubricate, slack, alignment
Replace
●

●

●
Use chain lube
Chain slack: 40 ~ 50 mm
(1.57 ~ 1.97 in)
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolant
Inspect hoses
●

●

●

●

●
Every two years
OUTSIDE NUTS AND BOLTS
Retighten
●

●
Refer to “STARTING
AND BREAK-IN” section
in the CHAPTER 1.
AIR FILTER
Clean and lubricate
Replace
●

●

●
Use foam air-filter oil or
equivalent oil
OIL FILTER
Replace
●

●

OIL STRAINER (frame)
Clean
●

FRAME
Clean and inspect
●

●

FUEL TANK, COCK
Clean and inspect
●

●

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
●

●

●

●

●

●

●

●

●

●

●

●
Every one year ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)
As re-
quiredRemarks


3