2002 YAMAHA WR 250F oil

4 - 61
ENG

OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
2. Install:

Bearing
1

NOTE:

Install the bearing by pressing its outer race
parallel.
Impeller shaft
1. Install:

Impeller shaft
1


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
lithium soap base grease on the oil seal lip
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)

Right crankcase cover
1. Install:

Dowel pin
1


O-ring
2


Collar
3


Gasket
4

NOTE:

Apply the lithium soap base grease on the O-
ring.

4 - 62
ENG

OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
2. Install:

Right crankcase cover
1


Bolt (right crankcase cover)
2

NOTE:


Apply the engine oil on the impeller shaft
end.

Mesh the impeller shaft gear
3
with primary
drive gear
4
.

Tighten the bolts in stage, using a crisscross
pattern.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

Kickstarter crank
1. Install:

Kickstarter crank
1


Washer
2


Bolt (kickstarter crank)
3

NOTE:

Install the kickstarter crank so that the kick-
starter crank is as vertical as possible with the
distance
a
between the kickstarter crank and
the frame being 8 mm (0.31 in) or more.
2. Install:

Oil hose
1


Bolt (oil hose)
2

T R..33 Nm (3.3 m · kg, 24 ft · lb)
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

T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)

4 - 63
ENG

OIL FILTER ELEMENT, WATER PUMP AND RIGHT
CRANKCASE COVER
Water pump housing
1. Install:

Dowel pin
1


O-ring
2
NOTE:
Apply the lithium soap base grease on the O-
ring.
2. Install:
Water pump housing 1
Bolt (water pump housing) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Oil filter element
1. Install:
Oil filter element 1
O-ring 2
Oil filter element cover 3
Bolt (oil filter element cover)
NOTE:
Apply the lithium soap base grease on the O-
ring.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 64
ENGBALANCER
BALANCER
Extent of removal:1 Balancer shaft drive gear2 Balancer shaft
Extent of removal Order Part name Q’ty Remarks
BALANCER REMOVAL
Preparation for removal Primary driven gear Refer to “CLUTCH” section.
Right crankcase cover Refer to “OIL FILTER ELEMENT,
WATER PUMP AND RIGHT CRANK-
CASE COVER” section.
Stator Refer to “CDI MAGNETO” section.
1 Nut (primary drive gear) 1
Refer to “REMOVAL POINTS”.
2 Nut (balancer shaft driven gear) 1
3 Lock washer 1
4 Primary drive gear 1
5 Balancer shaft drive gear 1
6 Lock washer 1
7 Balancer shaft driven gear 1
8 Balancer shaft 1 Refer to “REMOVAL POINTS”.
2
1
2

4 - 66
ENGBALANCER
ASSEMBLY AND INSTALLATION
Balancer shaft, balancer shaft drive gear
and balancer shaft driven gear
1. Install:
Balancer shaft 1
NOTE:
Apply the engine oil on the bearing.
When installing the balancer shaft, align the
center a of the balancer shaft weight along
the line connecting the centers of the crank-
shaft and balancer shaft.
2. Install:
Balancer shaft driven gear 1
NOTE:
Install the balancer shaft driven gear onto the
balancer shaft while aligning the punch mark
a on the balancer shaft driven gear with the
lower spline b on the balancer shaft end.
3. Install:
Balancer shaft drive gear 1
NOTE:
Align the punched mark a on the balancer
shaft drive gear with the punched mark b on
the balancer shaft driven gear 2.
Align the punched mark c on the balancer
shaft drive gear with the lower spline d on
the crankshaft end.
4. Install:
Lock washer 1
Nut (balancer shaft driven gear) 2
Primary drive gear 3
Nut (primary drive gear) 4
NOTE:
Install the primary drive gear with its stepped
side a facing the engine.
Place an aluminum plate b between the
teeth of the balancer shaft drive gear 5 and
driven gear 6.
5. Bend the lock washer tab.
T R..50 Nm (5.0 m · kg, 3.6 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)

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ENGOIL PUMP
OIL PUMP
Extent of removal:1 Oil pump removal2 Oil pump disassembly
Extent of removal Order Part name Q’ty Remarks
OIL PUMP REMOVAL AND DIS-
ASSEMBLY
Preparation for removal Primary driven gear Refer to “CLUTCH” section.
Right crankcase cover Refer to “OIL FILTER ELEMENT,
WATER PUMP AND RIGHT CRANK-
CASE COVER” section.
1 Circlip 1
2 Washer 1
3 Oil pump drive gear 1
4 Oil pump assembly 1
5 Outer rotor 2 1
6 Circlip 1
7 Inner rotor 2 1
8 Dowel pin 1
9 Oil pump cover 1
10 Outer rotor 1 1
11Inner rotor 1
1
2
1

4 - 68
ENGOIL PUMP
Extent of removal Order Part name Q’ty Remarks
12 Dowel pin 1
13 Washer 1
14 Oil pump drive shaft 1
15 Rotor housing 1
2

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ENGOIL PUMP
INSPECTION
Oil pump
1. Inspect:
Oil pump drive gear 1
Oil pump drive shaft 2
Rotor housing 3
Oil pump cover 4
Cracks/wear/damage → Replace.
1
32
4
2. Measure:
Tip clearance a
(between the inner rotor 1 and outer
rotor 2)
Side clearance b
(between the outer rotor 2 and rotor
housing 3)
Housing and rotor clearance c
(between the rotor housing 3 and
rotors 1 2)
Out of specification → Replace the oil
pump assembly.
Tip clearance a:
0.12 mm or less
(0.0047 in or less)
: 0.20 mm (0.008 in)
Side clearance b:
0.09 ~ 0.17 mm (0.0035 ~ 0.0067 in)
: 0.24 mm (0.009 in)
Housing and rotor clearance c:
0.03 ~ 0.10 mm (0.0012 ~ 0.0039 in)
: 0.17 mm (0.0067 in)
3. Check:
Unsmooth → Repeat steps #1 and #2
or replace the defective parts.