2003 YAMAHA YZ450F oil

1 - 14
GEN
INFO
DECOMPRESSION LEVER
INSTALLATION OF DECOMPRESSION
LEVER
Preparations
1. Remove the seat.
2. Drain the coolant.
Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
3. Remove:
Radiator
Refer to “RADIATOR” section in the
CHAPTER 4.
Cylinder head cover
Refer to “CAMSHAFTS” section in the
CHAPTER 4.
Number plate
4. Remove:
Plug 1
Bolt 2
Plain washer 3
NOTE:
Make a hole in the resin side a and remove
the plug.
Installation
1. Install:
Oil seal 1
NOTE:
Install the oil seal, as shown, where the plug
was removed.
Apply the lithium soap base grease on the oil
seal lip.
2. Install:
Torsion spring 1
Decompression shaft 2
Plain washer 3
Bolt (decompression shaft) 4
Decompression cable guide 5
Bolt (decompression cable guide) 6
Decompression cable 7
NOTE:
When installing the decompression shaft,
install the torsion spring in the location as
shown.
For the decompression shaft securing bolt
and plain washer, use the ones removed
from the same machine.
Apply the engine oil on the decompression
shaft.
23
1 a
1B
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

GEN
INFO
1 - 22
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.
Frame to rear frame
Fuel tank to frame
Silencer to rear frame
Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering shaft to frame
Steering shaft to handle crown
Handle crown to handlebar
Front fork to handle crown
Front fork to under bracket
Assembly of links
Link to frame
Link to shock absorber
Link to swingarm
Shock absorber to frame
Tightening of pivot shaft
Tightening of front axle
Tightening of axle holder
Tightening of rear axle
Wheel to sprocket
Caliper to front fork
Brake disc to wheel
Tightening of union bolt
Master cylinder to handlebar
Tightening of air bleeder
Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Master cylinder to frame
Tightening of air bleeder
Fuel tank to fuel cock
Tightening of oil hose clamp Frame construction
Combined seat and tank
Exhaust system
Engine mounting
Steering Steering shaft to
handlebar
Suspension Front Steering shaft to front
fork
Rear For link type
Rear Installation of shock
absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel system
Lubrication system

1 - 24
GEN
INFO
CLEANING AND STORAGE
8. Automotive wax may be applied to all
painted or chromed surfaces. Avoid com-
bination cleaner-waxes, as they may con-
tain abrasives.
9. After completing the above, start the
engine and allow it to idle for several min-
utes.
EC1B2001
STORAGE
If your machine is to be stored for 60 days or
more, some preventive measures must be
taken to avoid deterioration. After cleaning the
machine thoroughly, prepare it for storage as
follows:
1. Drain the fuel tank, fuel lines, and the
carburetor float bowl.
2. Remove the spark plug, pour a table-
spoon of SAE 10W-30 motor oil in the
spark plug hole, and reinstall the plug.
With the engine stop switch pushed in,
kick the engine over several times to coat
the cylinder walls with oil.
3. Remove the drive chain, clean it thor-
oughly with solvent, and lubricate it.
Reinstall the chain or store it in a plastic
bag tied to the frame.
4. Lubricate all control cables.
5. Block the frame up to raise the wheels off
the ground.
6. Tie a plastic bag over the exhaust pipe
outlet to prevent moisture from entering.
7. If the machine is to be stored in a humid
or salt-air environment, coat all exposed
metal surfaces with a film of light oil. Do
not apply oil to rubber parts or the seat
cover.
NOTE:
Make any necessary repairs before the
machine is stored.

SPEC

2 - 1
GENERAL SPECIFICATIONS
EC200000
SPECIFICATIONS
EC211000
GENERAL SPECIFICATIONS
Model name: YZ450FR (USA)
YZ450F (EUROPE)
YZ450F(R) (CDN, AUS, NZ, ZA)
Model code number: 5TA1 (USA)
5TA2 (EUROPE)
5TA4 (CDN, AUS, NZ, ZA)
Dimensions:
Overall length 2,171 mm (85.5 in)
Overall width 827 mm (32.6 in)
Overall height 1,303 mm (51.3 in)
Seat height 995 mm (39.2 in)
Wheelbase 1,485 mm (58.5 in)
Minimum ground clearance 371 mm (14.6 in)
Basic weight:
With oil and full fuel tank 113.0 kg (249 lb)
Engine:
Engine type Liquid cooled 4-stroke, DOHC
Cylinder arrangement Single cylinder, forward inclined
Displacement 449 cm
3

(15.8 Imp oz, 15.2 US oz)
Bore
×
stroke 95.0
×
63.4 mm (3.74
×
2.50 in)
Compression ratio 12.5 : 1
Starting system Kick starter
Lubrication system: Dry sump
Oil type or grade:
Engine oil (For USA and CDN)
At 5 ˚C (40 ˚F) or higher
Å

Yamalube 4 (20W-40) or SAE 20W-40 type SG
motor oil (Non-Friction modified)
At 15 ˚C (60 ˚F) or lower
ı

Yamalube 4 (10W-30) or SAE 10W-30 type SG
motor oil (Non-Friction modified) and/or
Yamalube 4-R (15W-50) (Non-Friction modi-
fied)
(Except for USA and CDN)
API “SG” or higher grade
-20
-4-10
140
3010
5020
6830
8640 50
104
122°CTemp.
°F
10W-30
10W-40
20W-40
20W-50
15W-40

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): 1.2 L (1.06 Imp qt, 1.27 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 7.0 L (1.54 Imp gal, 1.85 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: USA, CDN, ZA,
AUS, NZEUROPE
Primary reduction system Gear
←
Primary reduction ratio 62/22 (2.818)
←
Secondary reduction system Chain drive
←
Secondary reduction ratio 48/14 (3.429) 47/14 (3.357)
Transmission type Constant mesh,
4-speed
←
Operation Left foot operation
←
Gear ratio: 1st 27/14 (1.929)
←
2nd 25/16 (1.563)
←
3rd 23/18 (1.278)
←
4th 21/20 (1.050)
←
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 (For USA, CDN, ZA, AUS, NZ
and F)
80/100-21 51R (For EUROPE except F)
Size (rear) 110/90-19 62M (For USA, CDN, ZA, AUS, NZ
and F)
110/90-19 NHS (For EUROPE except F)
Tire pressure (front and rear) 100 kPa (1.0 kgf/cm
2

, 15 psi)

2

SPEC

2 - 3
GENERAL SPECIFICATIONS
Brake:
Front brake type Single disc brake
Operation Right hand operation
Rear brake type Single disc brake
Operation Right foot operation
Suspension:
Front suspension Telescopic fork
Rear suspension Swingarm (link type monocross suspension)
Shock absorber:
Front shock absorber Coil spring/oil damper
Rear shock absorber Coil spring/gas, oil damper
Wheel travel:
Front wheel travel 300 mm (11.8 in)
Rear wheel travel 315 mm (12.4 in)
Electrical:
Ignition system CDI magneto

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 Wire mesh 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 117.8 mm (4.6 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) 0.71 L (0.62 Imp qt, 0.75 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit