2012 YAMAHA YZ250F wheel

4-46
KICK SHAFT AND SHIFT SHAFT
KICK SHAFT AND SHIFT SHAFT
REMOVING THE KICK SHAFT AND SHIFT SHAFT
Order Part name Q'ty Remarks
Oil pump Refer to "OIL PUMP" section.
1 Kick idle gear 1
2 Kick shaft assembly 1 Refer to removal section.
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
11 Collar 1
12 Torsion spring 1
13 Roller 1
14 Shift guide 1 Refer to removal section.
15 Shift lever assembly 1 Refer to removal section.
16 Shift lever 1

4-48
KICK SHAFT AND SHIFT SHAFT
REMOVING THE KICK SHAFT
ASSEMBLY
1. Remove:
• Kick shaft assembly "1"
Unhook the torsion spring "2" from
the hole "a" in the crankcase.
REMOVING THE SHIFT GUIDE
AND SHIFT LEVER ASSEMBLY
1. Remove:
• Bolt (shift guide)
• Shift guide "1"
• Shift lever assembly "2"
The shift lever assembly is disassem-
bled at the same time as the shift
guide.
REMOVING THE SEGMENT
1. Remove:
• Bolt (segment) "1"
• Segment "2"
Turn the segment counterclockwise
until it stops and loosen the bolt.
If the segment gets an impact, it
may be damaged. Take care not to
give an impact to the segment
when removing the bolt.
CHECKING THE KICK SHAFT AND
RATCHET WHEEL
1. Check:
• Ratchet wheel "1" smooth move-
ment
Unsmooth movement→Replace.
• Kick shaft "2"
Wear/damage→Replace.
• Spring "3"
Broken→Replace.
CHECKING THE KICK GEAR, KICK
IDLE GEAR AND RATCHET
WHEEL
1. Inspect:
• Kick gear "1"
• Kick idle gear "2"
• Ratchet wheel "3"
• Gear teeth "a"
• Ratchet teeth "b"
Wear/damage→Replace.
CHECKING THE SHIFT SHAFT
1. Inspect:
• Shift shaft "1"
Bend/damage→Replace.
• Spring "2"
Broken→Replace.CHECKING THE SHIFT GUIDE AND
SHIFT LEVER ASSEMBLY
1. Inspect:
• Shift guide "1"
• Shift lever "2"
•Pawl "3"
• Pawl pin "4"
• Spring "5"
Wear/damage→Replace.
CHECKING THE STOPPER LEVER
1. Inspect:
• Stopper lever "1"
Wear/damage→Replace.
• Torsion spring "2"
Broken→Replace.
INSTALLING THE SEGMENT
1. Install:
• Segment "1"
• Bolt (segment)
Align the notch "a" on the segment
with the pin "b" on the shift cam.
If the segment gets an impact, it
may be damaged. Take care not to
give an impact to the segment
when tightening the bolt.
Bolt (segment):
30 Nm (3.0 m•kg, 22
ft•lb)

4-49
KICK SHAFT AND SHIFT SHAFT
INSTALLING THE STOPPER
LEVER
1. Install:
• Torsion spring "1"
• Stopper lever "2"
• Bolt (stopper lever) "3"
Align the stopper lever roller with the
slot on segment.
INSTALLING THE SHIFT GUIDE
AND SHIFT LEVER ASSEMBLY
1. Install:
• Spring "1"
• Pawl pin "2"
•Pawl "3"
To shift lever "4".
Apply the engine oil on the spring,
pawl pin and pawl.
2. Install:
• Shift lever assembly "1"
To shift guide "2".
3. Install:
• Shift lever assembly "1"
• Shift guide "2"
• 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"
INSTALLING THE SHIFT SHAFT
1. Install:
• Roller "1"
• Collar "2"
• Torsion spring "3"
• Shift shaft "4"
Apply the engine oil on the roller and
shift shaft.
2. Install:
• Shift pedal "1"
• Bolt (shift pedal) "2"
Install with the punch mark "a" on the
shift pedal in alignment with the
punch mark "b" on the shift shaft.
INSTALLING THE 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".
• 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".
Make sure the stopper "a" of the tor-
sion spring fits into the hole "b" on the
kick shaft.
3. Install:
• Spring guide "1"
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.
Bolt (stopper lever):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt (shift guide):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Bolt (shift pedal):
12 Nm (1.2 m•kg, 8.7
ft•lb)

4-50
KICK SHAFT AND SHIFT SHAFT
4. Install:
• Kick shaft assembly "1"
• Washer "2"
• Apply the molybdenum disulfide
grease on the contacting surfaces
of the kick shaft stopper "a" and kick
shaft ratchet wheel guide "3".
• Apply the engine oil on the kick
shaft.
• Slide the kick shaft assembly into
the crankcase and make sure the
kick shaft stopper "a" fits into the
kick shaft ratchet wheel guide.
5. Hook:
• Torsion spring "1"
Turn the torsion spring clockwise and
hook into the proper hole "a" in the
crankcase.
INSTALLING THE KICK IDLE
GEAR
1. Install:
• Kick idle gear "1"
• Washer "2"
• Circlip "3"
• Apply the engine oil on the kick idle
gear inner circumference.
• Install the kick idle gear with its de-
pressed side "a" toward you.

4-52
CDI MAGNETO
REMOVING THE ROTOR
1. Remove:
• Nut (rotor) "1"
• Washer "2"
Use the rotor holding tool "3".
2. Remove:
• Rotor "1"
Use the flywheel puller "2".
When installing the flywheel puller,
turn it counterclockwise.
CHECKING THE CDI MAGNETO
1. Inspect:
• Rotor inner surface "a"
• Stator outer surface "b"
Damage→Inspect the crankshaft
runout and crankshaft bearing.
If necessary, replace CDI magne-
to and/or stator.CHECKING THE WOODRUFF KEY
1. Inspect:
• Woodruff key "1"
Damage→Replace.
INSTALLING THE CDI MAGNETO
1. Install:
• Stator "1"
• Screw (stator) "2"
• Apply the sealant on the grommet
of the CDI magneto lead.
• Tighten the screws using the T30
bit.
2. Install:
• Woodruff key "1"
• Rotor "2"
• Clean the tapered portions of the
crankshaft and rotor.
• When installing the woodruff key,
make sure that its flat surface "a" is
in parallel with the crankshaft center
line "b".
• When installing the rotor, align the
keyway "c" of the rotor with the
woodruff key.
3. Install:
• Washer "1"
• Nut (rotor) "2"
Use the rotor holding tool "3".
4. Connect:
• CDI magneto lead
Refer to "CABLE ROUTING DIA-
GRAM" section in the CHAPTER
2.
5. Install:
• Dowel pin
• Gasket (left crankcase cover)
• Left crankcase cover "1"
• Hose guide (cylinder head breath-
er hose) "2"
• Bolt (left crankcase cover)
Tighten the bolts in stage, using a
crisscross pattern.
Rotor holding tool:
YU-1235/90890-01235
Flywheel puller:
YM-1189/90890-01189
Screw (stator):
10 Nm (1.0 m•kg,
7.2ft•lb)
YAMAHA Bond No. 1215
(ThreeBond
® No. 1215):
90890-85505
Nut (rotor):
56 Nm (5.6 m•kg, 40
ft•lb)
Rotor holding tool:
YU-1235/90890-01235
Bolt (left crankcase cov-
er):
10 Nm (1.0 m•kg, 7.2
ft•lb)

4-64
TRANSMISSION, SHIFT CAM AND SHIFT FORK
REMOVING THE TRANSMISSION
1. Remove:
• Main axle "1"
• Drive axle "2"
• Shift cam
• Shift fork 3
• Shift fork 2
• Shift fork 1
• Remove assembly with the collar
"3" installed to the crankcase.
• Remove assembly carefully. Note
the position of each part. Pay partic-
ular attention to the location and di-
rection of shift forks.
• Remove the main axle, drive axle,
shift cam and shift fork all together
by tapping lightly on the transmis-
sion drive axle with a soft hammer.
CHECKING THE GEARS
1. Inspect:
• Matching dog "a"
• Gear teeth "b"
• Shift fork groove "c"
Wear/damage→Replace.
2. Inspect:
• O-ring "1"
Damage→Replace.
3. Check:
• Gears movement
Unsmooth movement→Repair or
replace.CHECKING THE BEARING
1. Inspect:
•Bearing "1"
Rotate inner race with a finger.
Rough spot/seizure→Replace.
CHECKING THE SHIFT FORK,
SHIFT CAM AND SEGMENT
1. Inspect:
• Shift fork "1"
Wear/damage/scratches→Re-
place.
2. Inspect:
• Shift cam "1"
• Segment "2"
Wear/damage→Replace.
3. Check:
• Shift fork movement
Unsmooth operation→Replace
shift fork.
For a malfunctioning shift fork, re-
place not only the shift fork itself but
the two gears each adjacent to the
shift fork.
INSTALLING THE TRANSMISSION
1. Install:
• 5th pinion gear (24T) "1"
• 3rd pinion gear (18T) "2"
•Collar "3"
• 4th pinion gear (18T) "4"
• 2nd pinion gear (16T) "5"
To main axle "6".
Apply the molybdenum disulfide oil
on the inner and end surface of the
idler gear and on the inner surface of
the sliding gear, then install.
2. Install:
• 2nd wheel gear (28T) "1"
• 4th wheel gear (22T) "2"
• 3rd wheel gear (26T) "3"
• 5th wheel gear (25T) "4"
• 1st wheel gear (30T) "5"
• O-ring "6"
To drive axle "7".
• Apply the molybdenum disulfide oil
on the inner and end surface of the
idler gear and on the inner surface
of the sliding gear, then install.
• Apply the lithium soap base grease
on the O-ring.

4-65
TRANSMISSION, SHIFT CAM AND SHIFT FORK
3. Install:
• Washer "1"
• Circlip "2"
• Be sure the circlip sharp-edged cor-
ner "a" is positioned opposite side
to the washer and gear "b".
• Install the circlip with its ends "c"
settled evenly on the spline crests.
4. Install:
•Collar "1"
• Apply the lithium soap base grease
on the oil seal lip.
• When installing the collar into the
crankcase, pay careful attention to
the crankcase oil seal lip.
5. Install:
• Shift fork 1 (L) "1"
• Shift fork 2 (C) "2"
• Shift fork 3 (R) "3"
• Shift cam "4"
To main axle and drive axle.
• Apply the engine oil on the shift fork
grooves.
• Mesh the shift fork #1 (L) with the
4th wheel gear "5" and #3 (R) with
the 5th wheel gear "7" on the drive
axle.
• Mesh the shift fork #2 (C) with the
3rd pinion gear "6" on the main ax-
le.
6. Install:
• Transmission assembly "1"
To left crankcase "2".
Apply the engine oil on the bearings
and guide bars.
7. Check:
• Shifter operation
• Transmission operation
Unsmooth operation→Repair.

5-1
FRONT WHEEL AND REAR WHEEL
CHASSIS
This section is intended for those who have basic knowledge and skill concerning the servicing of Yamaha motorcycles
(e.g., Yamaha dealers, service engineers, etc.) Those who have little knowledge and skill concerning servicing are request-
ed not to undertake inspection, adjustment, disassembly, or reassembly only by reference to this manual. It may lead to
servicing trouble and mechanical damage.
FRONT WHEEL AND REAR WHEEL
REMOVING THE FRONT WHEEL
Order Part name Q'ty Remarks Hold the machine by placing the suitable stand
under the engine. Refer to "HANDLING NOTE".
1 Bolt (axle holder) 4 Only loosening.
2 Nut (front wheel axle) 1
3 Front wheel axle 1
4 Front wheel 1
5 Collar 2
6 Oil seal 2
7 Bearing 2 Refer to removal section.
8 Brake disc 1