2004 YAMAHA WR 450F REAR WHEEL

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 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.1-14
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-14 ~ 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-10
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
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated properly.P.3-33 ~ 36
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-44 ~ 45
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-45 ~ 46
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-36 ~ 43
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.—
Sprocket Check that the driven sprocket tightening bolt is not loose. P.3-33
Lubrication Check for smooth operation. Lubricate if necessary. P.3-47
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-19
Lead connectorsCheck that the AC 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 ~ 21

3 - 30
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
3. Inspect:
Brake fluid level
Refer to “BRAKE FLUID LEVEL
INSPECTION” section.
4. Check:
Brake lever operation
A softy or spongy feeling → Bleed
brake system.
Refer to “BRAKE SYSTEM AIR
BLEEDING” section.
Install the pad pin plug B.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
EC366060
REAR BRAKE PAD INSPECTION AND
REPLACEMENT
1. Inspect:
Brake pad thickness a
Out of specification → Replace as a
set.
2. Replace:
Brake pad
Brake pad thickness a:
Standard
6.4 mm (0.25 in) 1.0 mm (0.04 in)
Brake pad replacement steps:
Remove the protector 1 and pad pin plug
2.
Loosen the pad pin 3.
Remove the rear wheel 4 and caliper 5.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.

3 - 31
INSP
ADJ
REAR BRAKE PAD INSPECTION AND REPLACEMENT
Remove the pad pin 6 and brake pads 7.
Connect the transparent hose 8 to the
bleed screw 9 and place the suitable con-
tainer under its end.
Loosen the bleed screw and push the cali-
per piston in.
CAUTION:
Do not reuse the drained brake fluid.
Tighten the bleed screw.
T R..
Bleed screw:
6 Nm (0.6 m • kg, 4.3 ft • lb)
Install the brake pad 0 and pad pin A.
NOTE:
Install the brake pads with their projections
a into the caliper recesses b.
Temporarily tighten the pad pin at this
point.
Install the caliper B and rear wheel C.
Refer to “FRONT WHEEL AND REAR
WHEEL” section in the CHAPTER 5.
Tighten the pad pin D.
T R..
Pad pin:
18 Nm (1.8 m • kg, 13 ft • lb)
Install the pad pin plug E and protector F.
T R..
Pad pin plug:
3 Nm (0.3 m • kg, 2.2 ft • lb)
Bolt (protector):
7 Nm (0.7 m • kg, 5.1 ft • lb)

3 - 35
INSP
ADJ
DRIVE CHAIN SLACK ADJUSTMENT
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
Drive chain slack a
Above the seal guard installation bolt.
Out of specification → Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust the chain slack
with the rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 50 mm (1.6 ~ 2.0 in)
3. Adjust:
Drive chain slack
Drive chain slack adjustment steps:
Loosen the axle nut 1 and locknuts 2.
Adjust the chain slack by turning the
adjusters 3.
To tighten → Turn the adjuster 3 coun-
terclockwise.
To loosen → Turn the adjuster 3 clock-
wise and push wheel for-
ward.
Turn each adjuster exactly the same
amount to maintain correct axle alignment.
(There are marks a on each side of the
chain puller alignment.)
NOTE:
Turn the adjuster so that the chain is in line
with the sprocket, as viewed from the rear.
CAUTION:
Too small chain slack will overload the
engine and other vital parts; keep the
slack within the specified limits.

3 - 40
INSP
ADJREAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENT
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Remove:
Rear frame
3. Loosen:
Locknut 1
4. Adjust:
Spring preload
By turning the adjuster 2.
* For EUROPE, AUS, NZ and ZA
NOTE:
Be sure to remove all dirt and mud from
around the locknut and adjuster before
adjustment.
The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
Locknut
6. Install:
Rear frame (upper)
Rear frame (lower) Stiffer →Increase the spring preload.
(Turn the adjuster 2 in.)
Softer →Decrease the spring preload.
(Turn the adjuster 2 out.)
Spring length (installed) a:
Standard length Extent of adjustment
245 mm (9.65 in)
* 247 mm (9.72 in)240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)
T R..32 Nm (3.2 m · kg, 23 ft · lb)
T R..29 Nm (2.9 m · kg, 21 ft · lb)

5 - 1
CHAS

EC500000
CHASSIS
EC590000
FRONT WHEEL AND REAR WHEEL
EC598000
FRONT WHEEL
FRONT WHEEL AND REAR WHEEL
Extent of removal:
1
Front wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
FRONT WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Trip meter cable 1
2 Hose cover 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Bolt (axle holder) 4 Only loosening.
5 Nut (front wheel axle) 1
6 Front wheel axle 1
7 Front wheel 1
8 Trip meter gear unit 1
9 Collar 1
10 Oil seal 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
12 Brake disc 1
2
31
3

5 - 2
CHAS

EC598100
REAR WHEEL
Extent of removal:
1
Rear wheel removal
2
Wheel bearing removal
3
Brake disc removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
REAR WHEEL REMOVAL
Hold the machine by placing the
suitable stand under the engine.
WARNING

Support the machine securely so there is no
danger of it falling over.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10Brake disc
1
2
31
3

FRONT WHEEL AND REAR WHEEL

5 - 3
CHAS

FRONT WHEEL AND REAR WHEEL
EC593000
REMOVAL POINTS
EC523101
Rear wheel
1. Remove:

Wheel
1

NOTE:

Push the wheel forward and remove the drive
chain
2
.
EC513201
Wheel bearing (if necessary)
1. Remove:

Bearing
1

NOTE:

Remove the bearing using a general bearing
puller
2
.
EC594000
INSPECTION
EC514100
Wheel
1. Measure:

Wheel runout
Out of limit
→
Repair/replace.
2. Inspect:

Bearing
Rotate inner race with a finger.
Rough spot/seizure
→
Replace.
NOTE:

Replace the bearings, oil seal and wheel collar
as a set.
Wheel runout limit:
Radial
1
: 2.0 mm (0.08 in)
Lateral
2
: 2.0 mm (0.08 in)