2005 YAMAHA YZ250F oil

4 - 62
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 - 63
ENGBALANCER
BALANCER
Extent of removal:
1 Balancer shaft drive gear
2 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 - 65
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, 36 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)

4 - 66
ENGOIL PUMP
OIL PUMP
Extent of removal:
1 Oil pump removal
2 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
11 Inner rotor 1 1
2
1

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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.

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ENGOIL PUMP
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
Oil pump drive shaft 1
Washer 2
Dowel pin 3
Inner rotor 1 4
NOTE:
Apply the engine oil on the oil pump drive
shaft and inner rotor 1.
Fit the dowel pin into the groove in the inner
rotor 1.
2. Install:
Outer rotor 1 1
NOTE:
Apply the engine oil on the outer rotor 1.
3. Install:
Oil pump cover 1
Screw (oil pump cover) 2
Dowel pin 3
Inner rotor 2 4
Circlip 5
NOTE:
Apply the engine oil on the inner rotor 2.
Fit the dowel pin into the groove in the inner
rotor 2.
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)

4 - 70
ENG
4. Install:
Outer rotor 2 1
Dowel pin 2
Oil pump assembly 3
Bolt (oil pump assembly)
[L = 25 mm (0.94 in)] 4
Bolt (oil pump assembly)
[L = 30 mm (1.18 in)] 5
NOTE:
Apply the engine oil on the outer rotor 2.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
5. Install:
Oil pump drive gear 1
Washer 2
Circlip 3
NOTE:
Apply the engine oil on the oil pump drive gear
inner circumference.
OIL PUMP