2003 YAMAHA YZ450F oil

4 - 53
ENGCLUTCH
3. Bend the lock washer 1 tab.
4. Install:
Friction plate 1
Clutch plate 2
NOTE:
Install the clutch plates and friction plates
alternately on the clutch boss, starting with a
friction plate and ending with a friction plate.
Apply the engine oil on the friction plates and
clutch plates.
2 1
E
5. Install:
Bearing 1
Plain washer 2
Circlip 3
To push rod 1 4.
NOTE:
Apply the engine oil on the bearing and plain
washer.
New
6. Install:
Push rod 2 1
Ball 2
Push rod 1 3
NOTE:
Apply the engine oil on the push rod 1, 2 and
ball.

4 - 55
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)
OIL FILTER, WATER PUMP AND CRANKCASE COVER (RIGHT)
Extent of removal:1 Oil filter removal2 Water pump removal
3 Crankcase cover (right) removal
Extent of removal Order Part name Q’ty Remarks
OIL FILTER, WATER PUMP
AND CRANKCASE COVER
(RIGHT) REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
Drain the coolant. Refer to “COOLANT REPLACEMENT”
section in the CHAPTER 3.
Exhaust pipe Refer to “EXHAUST PIPE AND
SILENCER” section.
Brake pedal Refer to “ENGINE REMOVAL” section.
Clutch cover Refer to “CLUTCH” section.
1 Oil filter cover 1
2 Oil filter 1
3 Coolant pipe 2 1
4 Water pump housing 1
5 Pin 2
6 Oil delivery pipe 1
1
2
3

4 - 56
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
Extent of removal Order Part name Q’ty Remarks
7 Oil hose 1
8 Kick starter 1
9 Crankcase cover (right) 1
10 Gasket 1
11 Dowel pin/O-ring 4/2
12 Impeller 1
Refer to “REMOVAL POINTS”. 13 Plain washer 1
14 Impeller shaft 1
15 Oil seal 1 1
16 Oil seal 2 1
17 Bearing 1
2
3
2

4 - 57
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
REMOVAL POINTS
EC4G3110
Impeller shaft
1. Remove:
Impeller 1
Plain washer 2
Impeller shaft 3
NOTE:
Hold the impeller shaft on its width across the
flats a with spanners, etc. and remove the
impeller.
EC4G3210
Oil seal
NOTE:
It is not necessary to disassemble the water
pump, unless there is an abnormality such as
excessive change in coolant level, discolora-
tion of coolant, or milky transmission oil.
1. Remove:
Bearing 1
Oil seal 2
INSPECTION
EC444200
Impeller shaft
1. Inspect:
Impeller shaft 1
Bend/wear/damage → Replace.
Fur deposits → Clean.

4 - 58
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4H4600
Bearing
1. Inspect:
Bearing
Rotate inner race with a finger.
Rough spot/seizure → Replace.
EC444400
Oil seal
1. Inspect:
Oil seal
Wear/damage → Replace.
ASSEMBLY AND INSTALLATION
EC4G5110
Oil seal
1. Install:
Oil seal 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip.
Install the oil seal with its manufacture’s
marks or numbers facing inward.
Bearing
1. Install:
Bearing 1
NOTE:
Install the bearing by pressing its outer race
parallel.
New

4 - 59
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
EC4G5220
Impeller shaft
1. Install:
Impeller shaft 1
Plain washer 2
Impeller 3
NOTE:
Take care so that the oil seal lip is not dam-
aged or the spring does not slip off its posi-
tion.
When installing the impeller shaft, apply the
engine oil on the oil seal lip, bearing and
impeller shaft. And install the shaft while
turning it.
Hold the impeller shaft on its width across
the flats a with spanners, etc. and install the
impeller.
T R..14 Nm (1.4 m · kg, 10 ft · lb)
Crankcase cover (right)
1. Install:
Dowel pin 1
O-ring 2
Collar 3
Gasket 4 New
2. Install:
Crankcase cover (right) 1
Bolt
NOTE:
Apply the engine oil on the impeller shaft
end.
When installing the crankcase cover onto the
crankcase, be sure that the impeller shaft
end 2 aligns with the balancer end slot 3.
Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 60
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
Kick crank
1. Install:
Kick starter 1
Plain washer
Bolt (kick starter)
NOTE:
Install the kick starter so that the kick starter is
as vertical as possible with the distance a
between the kick starter and the frame being
5 mm (0.20 in) or more.
T R..33 Nm (3.3 m · kg, 24 ft · lb)
2. Install:
Oil hose 1
Bolt (oil hose) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
Copper washer 1
Oil delivery pipe 2
Union bolt (M8) 3
Union bolt (M10) 4
New
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
Water pump housing
1. Install:
Dowel pin 1
O-ring 2 New

4 - 61
ENG
OIL FILTER, WATER PUMP AND CRANKCASE COVER
(RIGHT)
2. Install:
Water pump housing 1
Bolt (water pump housing) 2
Plain washer 3
Coolant drain bolt 4
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
O-ring
Coolant pipe 1
Bolt (coolant pipe) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Oil filter
1. Install:
Oil filter 1
O-ring 2
Oil filter cover 3
Bolt (oil filter cover)
New
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)