2001 YAMAHA YZ250F oil

4 - 67
ENGOIL PUMP
INSPECTION
Oil pump
1. Inspect:
lOil pump drive gear 1
lOil pump drive shaft 2
lRotor housing 3
lOil pump cover 4
Cracks/wear/damage ® Replace.
1
32
4
2. Measure:
lTip clearance a
(between the inner rotor 1 and outer
rotor 2)
lSide clearance b
(between the outer rotor 2 and rotor
housing 3)
lHousing 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:
lUnsmooth ® Repeat steps #1 and #2
or replace the defective parts.

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ENGOIL PUMP
ASSEMBLY AND INSTALLATION
Oil pump
1. Install:
lOil pump drive shaft 1
lWasher 2
lDowel pin 3
lInner rotor 1 4
NOTE:
lApply the engine oil on the oil pump drive
shaft and inner rotor 1.
lFit the dowel pin into the groove in the inner
rotor 1.
2. Install:
lOuter rotor 1 1
NOTE:
Apply the engine oil on the outer rotor 1.
3. Install:
lOil pump cover 1
lScrew (oil pump cover) 2
lDowel pin 3
lInner rotor 2 4
lCirclip 5
NOTE:
lApply the engine oil on the inner rotor 2.
lFit the dowel pin into the groove in the inner
rotor 2.
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)

4 - 69
ENG
4. Install:
lOuter rotor 2 1
lDowel pin 2
lOil pump assembly 3
lBolt (oil pump assembly)
[L = 25 mm (0.94 in)] 4
lBolt (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:
lOil pump drive gear 1
lWasher 2
lCirclip 3
NOTE:
Apply the engine oil on the oil pump drive gear
inner circumference.
OIL PUMP

4 - 70
ENGKICK SHAFT AND SHIFT SHAFT
KICK SHAFT AND SHIFT SHAFT
Extent of removal:1 Kick shaft removal2 Kick shaft disassembly
3 Shift shaft removal4 Segment removal
Extent of removal Order Part name Q’ty Remarks
KICK SHAFT AND SHIFT
SHAFT REMOVAL
Preparation for removal Oil pump Refer to “OIL PUMP” section.
1 Kick idle gear 1
2 Kick shaft assembly 1 Refer to “REMOVAL POINTS”.
3 Spring guide 1
4 Torsion spring 1
5 Ratchet wheel 1
6 Kick gear 1
7 Kick shaft 1
8 Washer 1
9 Shift pedal 1
10 Shift shaft 1
11Collar
1
3
2
1
4
1

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ENGKICK SHAFT AND SHIFT SHAFT
EC4B5111
Stopper lever
1. Install:
lTorsion spring 1
lStopper lever 2
lBolt (stopper lever) 3
NOTE:
Align the stopper lever roller with the slot on
segment.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Shift guide and shift lever assembly
1. Install:
lSpring 1
lPawl pin 2
lPawl 3
To shift lever 4.
NOTE:
Apply the engine oil on the spring, pawl pin
and pawl.
2. Install:
lShift lever assembly 1
To shift guide 2.
3. Install:
lShift lever assembly 1
lShift guide 2
NOTE:
lThe shift lever assembly is installed at the
same time as the shift guide.
lApply the engine oil on the bolt (segment)
shaft.

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ENGKICK SHAFT AND SHIFT SHAFT
4. Install:
lBolt (shift guide) 1
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
Shift shaft
1. Install:
lRoller 1
lCollar 2
lTorsion spring 3
lShift shaft 4
NOTE:
Apply the engine oil on the roller and shift
shaft.
2. Install:
lShift pedal 1
lBolt (shift pedal) 2
NOTE:
When installing the shift pedal onto the shift
shaft, be sure that the center of the shift pedal
is about 2 mm a above the top of the footrest.
Kick shaft assembly
1. Install:
lKick gear 1
lWasher 2
lCirclip 3
lRatchet wheel 4
lSpring 5
lWasher 6
lCirclip 7
To kick shaft 8.
NOTE:
lApply the molybdenum disulfide oil on the
kick gear inner circumference.
lAlign the punch mark a on the ratchet wheel
with the punch mark b on the kick shaft.

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ENGKICK SHAFT AND SHIFT SHAFT
2. Install:
lTorsion spring 1
To kick shaft 2.
NOTE:
Make sure the stopper a of the torsion spring
fits into the hole b on the kick shaft.
3. Install:
lSpring guide 1
NOTE:
Slide the spring guide into the kick shaft, make
sure the groove a in the spring guide fits on
the stopper of the torsion spring.
4. Install:
lKick shaft assembly 1
lWasher 2
NOTE:
lApply the engine oil on the kick shaft.
lSlide the kick shaft assembly into the crank-
case, make sure the kick shaft stopper a fit
into their home position 3.
5. Hook:
lTorsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
lKick idle gear 1
lWasher 2
lCirclip 3
NOTE:
lApply the engine oil on the kick idle gear
inner circumference.
lInstall the kick idle gear with its depressed
side a toward you.

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ENGENGINE REMOVAL
EC4M0000
ENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for removal Hold the machine by placing the
suitable stand under the frame.
WARNING
Support the machine securely so there is nodanger of it falling over.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section.
Carburetor Refer to “CARBURETOR” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Decompression cable and guide Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Shift pedal Refer to “KICK SHAFT AND SHIFT
SHAFT” section.
Cylinder head breather hose and
oil tank breather hoseRefer to “CAMSHAFTS” section.
Drain the engine oil Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.