2006 YAMAHA YZ250F engine

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 with the kickstarter
crank and frame 15 mm (0.59 in) or more apart
a and the kickstarter crank and right crank-
case 3 mm (0.12 in) or more apart b.
2. Install:
Oil hose 1
Bolt (oil hose) 2
ba
T R..33 Nm (3.3 m · kg, 24 ft · lb)
T R..8 Nm (0.8 m · kg, 5.8 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 - 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, 36 ft · lb)
T R..75 Nm (7.5 m · kg, 54 ft · lb)

4 - 69
ENGOIL PUMP
OIL TANK
Extent of removal:
1 Oil tank
Extent of removal Order Part name Q’ty Remarks
OIL TANK REMOVAL
Preparation for removal Drain the engine oil. Refer to “ENGINE OIL REPLACEMENT”
section in the CHAPTER 3.
1 Oil hose 2 1
2 Oil hose 1 1
3 Dowel pin 2
4 Oil tank breather hose 1
5 Oil tank 1
6 Oil strainer 1
1

4 - 71
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 - 72
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

4 - 77
ENGKICK SHAFT AND SHIFT SHAFT
EC4B5111
Stopper lever
1. Install:
Torsion spring 1
Stopper lever 2
Bolt (stopper lever) 3
NOTE:
Align the stopper lever roller with the slot on
segment.
Shift guide and shift lever assembly
1. Install:
Spring 1
Pawl pin 2
Pawl 3
To shift lever 4.
NOTE:
Apply the engine oil on the spring, pawl pin
and pawl.
2. Install:
Shift lever assembly 1
To shift guide 2.
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
3. Install:
Shift lever assembly 1
Shift guide 2
NOTE:
The shift lever assembly is installed at the
same time as the shift guide.
Apply the engine oil on the bolt (segment)
shaft.
4. Install:
Bolt (shift guide) 1
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)

4 - 78
ENGKICK SHAFT AND SHIFT SHAFT
Shift shaft
1. Install:
Roller 1
Collar 2
Torsion spring 3
Shift shaft 4
NOTE:
Apply the engine oil on the roller and shift
shaft.
2. Install:
Shift pedal 1
Bolt (shift pedal) 2
NOTE:
When installing the shift pedal onto the shift
shaft, be sure that the center of the shift pedal
is about 1.4 mm (0.06 in) a above the top of
the footrest.
T R..12 Nm (1.2 m · kg, 8.7 ft · lb)
Kick shaft assembly
1. Install:
Kick gear 1
Washer 2
Circlip 3
Ratchet wheel 4
Spring 5
Washer 6
Circlip 7
To kick shaft 8.
NOTE:
Apply the molybdenum disulfide oil on the
inner circumferences of the kick gear and
ratchet wheel.
Align the punch mark a on the ratchet wheel
with the punch mark b on the kick shaft.
2. Install:
Torsion 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.

4 - 79
ENGKICK SHAFT AND SHIFT SHAFT
3. Install:
Spring 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:
Kick shaft assembly 1
Washer 2
NOTE:
Apply the molybdenum disulfide grease on
the contacting surfaces of the kick shaft stop-
per a and kick shaft ratchet wheel guide 3.
Apply the engine oil on the kick shaft.
Slide the kick shaft assembly into the crank-
case and make sure the kick shaft stopper a
fits into the kick shaft ratchet wheel guide.
5. Hook:
Torsion spring 1
NOTE:
Turn the torsion spring clockwise and hook
into the proper hole a in the crankcase.
Kick idle gear
1. Install:
Kick idle gear 1
Washer 2
Circlip 3
NOTE:
Apply the engine oil on the kick idle gear
inner circumference.
Install the kick idle gear with its depressed
side a toward you.