YAMAHA YZ250F 2010 Owners Manual

5-24
HANDLEBAR
HANDLEBAR
REMOVING THE HANDLEBAROrder Part name Q'ty Remarks Number plate Remove the band only.
1 Hot starter cable 1 Disconnect at the lever side.
2 Hot starter lever holder 1
3 Clutch cable 1 Disconnect at the lever side.
4 Clutch lever holder 1
5 Engine stop switch 1
6 Brake master cylinder 1 Refer to removal section.
7 Throttle cable cap 1
8 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
9 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
10 Right grip 1 Refer to removal section.
11 Tube guide 1
12 Collar 1
13 Left grip 1 Refer to removal section.
14 Handlebar upper holder 2
15 Handlebar 1
16 Handlebar lower holder 2

5-25
HANDLEBAR
REMOVING THE BRAKE MASTER
CYLINDER
1. Remove:• Brake master cylinder bracket "1"
• Brake master cylinder "2"
• Do not let the brake master cylin-der hang on the brake hose.
• Keep the brake master cylinder
cap side horizontal to prevent air
from coming in.
REMOVING THE GRIP
1. Remove:•Grip "1"
Blow in air between the handlebar or
tube guide and the grip. Then remove
the grip which has become loose.
CHECKING THE HANDLEBAR
1. Inspect:• Handlebar "1"Bends/cracks/damage →Re-
place.
Do not attempt to straighten a bent
handlebar as this may dangerous-
ly weaken the handlebar.
INSTALLING THE HANDLEBAR
1. Install: • Handlebar lower holder "1"
• Washer "2"
• Nut (handlebar lower holder) "3"
• Be sure the side of the handlebar lower holder having the greater dis-
tance "a" from the mounting bolt
center faces forward. And install it
in the hole "b" in the rear of the up-
per bracket.
• Apply the lithium soap base grease on the thread of the handlebar low-
er holder.
• Change in the direction back to front and installing position of the
handlebar lower holder allows the
front-to-rear offs et amount of the
handlebar position to be changed.
• Do not tighten the nut yet.
A. Forward
2. Install: • Handlebar "1"
• Handlebar upper holder "2"
• Bolt (handlebar upper holder) "3"
• The handlebar upper holder should be installed with the punched mark
"a" forward.
• Install the handlebar so that the marks "b" are in place on both
sides.
• Install the handlebar so that the pro- jection "c" of the handlebar upper
holder is positioned at the mark on
the handlebar as shown.
• First tighten the bolts on the front
side of the handlebar upper holder,
and then tighten the bolts on the
rear side.
Bolt (handlebar upper
holder): 28 Nm (2.8 m•kg, 20
ft•lb)

5-26
HANDLEBAR
3. Tighten:• Nut (handlebar lower holder) "1"
4. Install: • Left grip "1"Apply the adhesive to the handle-
bar "2".
• Before applying the adhesive, wipe off grease or oil on the handlebar
surface "a" with a lacquer thinner.
• Install the left grip to the handlebar so that the line "b" between the two
arrow marks faces straight upward.
5. Install:• Right grip "1"
•Collar "2"Apply the adhesive on the tube
guide "3".
• Before applying the adhesive, wipe
off grease or oil on the tube guide
surface "a" with a lacquer thinner.
• Install the grip to the tube guide so
that the grip match mark "b" and
tube guide slot "c" form the angle as
shown.
6. Install:• Collar "1"
• Grip cap cover "2"
• Throttle grip "3"
Apply the lithium soap base grease
on the throttle grip sliding surface.
7. Install:• Throttle cables "1"
To tube guide "2".
Apply the lithium soap base grease
on the throttle cable end and tube
guide cable winding portion.
8. Install:• Throttle cable cap "1"
• Screw (throttle cable cap) "2"
After tightening the screws, check
that the throttle grip "3" moves
smoothly. If it does not, retighten
the bolts for adjustment.
9. Install:• Grip cap cover "1"
• Cover (throttle cable cap) "2"
10. Install: • Brake master cylinder "1"
• Brake master cylinder bracket "2"
• Bolt (brake master cylinder brack-et) "3"
• Install the bracket so that the arrow
mark "a" faces upward.
• First tighten the bolt on the upper side of the brake master cylinder
bracket, and then tighten the bolt on
the lower side.
11. Install:
• Engine stop switch "1"
• Clutch lever holder "2"
• Bolt (clutch lever holder) "3"
• Hot starter lever holder "4"
• Bolt (hot starter lever holder) "5"
Nut (handlebar lower
holder):
34 Nm (3.4 m•kg, 24
ft•lb)
Screw (throttle cable
cap):4 Nm (0.4 m•kg, 2.9
ft•lb)
Bolt (brake master cylin-
der bracket): 9 Nm (0.9 m•kg, 6.5
ft•lb)
Bolt (clutch lever holder): 5 Nm (0.5 m•kg, 3.6
ft•lb)
Bolt (hot starter lever
holder): 4 Nm (0.4 m•kg, 2.9
ft•lb)

5-27
HANDLEBAR
• Clamp "6"
• The engine stop switch, clutch lever holder and clamp should be in-
stalled according to the dimensions
shown.
• Pass the engine stop switch lead in the middle of the clutch lever hold-
er.
12. Install:• Clutch cable "1"
• Hot starter cable "2"
Apply the lithium soap base grease
on the clutch cable end and hot start-
er cable end.
13. Adjust:
• Clutch lever free playRefer to "ADJUSTING THE
CLUTCH CABLE FREE PLAY"
section in the CHAPTER 3.
• Hot starter lever free play Refer to "ADJUSTING THE HOT
STARTER LEVER FREE PLAY"
section in the CHAPTER 3.

5-28
STEERING
STEERING
REMOVING THE STEERINGOrder Part name Q'ty Remarks TIGHTENING STEPS:
• Tighten ring nut. 38 Nm (3.8 m•kg, 27 ft•lb)
• Loosen it one turn.
• Retighten it. 7 Nm (0.7 m•kg, 5.1 ft•lb)
Hold the machine by placing the suitable stand
under the engine. Refer to "HANDLING NOTE".
Number plate Refer to "SEAT, FUEL TANK AND SIDE
COVERS" section in the CHAPTER 4.
Handlebar Refer to "HANDLEBAR" section.
1 Front fender 1
2 Steering stem nut 1
3 Front fork 2 Refer to "FRONT FORK" section.
4 Upper bracket 1
5 Steering ring nut 1 Refer to removal section.
6 Lower bracket 1
7 Bearing race cover 1
8 Upper bearing 1
9 Lower bearing 1 Refer to removal section.
10 Bearing race 2 Refer to removal section.

5-29
STEERING
HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
REMOVING THE STEERING RING
NUT
1. Remove:• Steering ring nut "1"Use the steering nut wrench "2".
Support the steering stem so that
it may not fall down.
REMOVING THE LOWER
BEARING
1. Remove:
• Lower bearing "1"Use the floor chisel "2".
Take care not to damage the steer-
ing shaft thread.
REMOVING THE BEARING RACE
1. Remove:
• Bearing race "1"Remove the bearing race using
long rod "2" and the hammer. CHECKING THE STEERING STEM
1. Inspect:
• Steering stem "1"Bend/damage →Replace.
CHECKING THE BEARING AND
BEARING RACE
1. Wash the bearings and bearing races with a solvent.
2. Inspect: •Bearing "1"
• Bearing race
Pitting/damage →Replace bear-
ings and bearing races as a set.
Install the bearing in the bearing
races. Spin the bearings by hand.
If the bearings hang up or are not
smooth in their operation in the
bearing races, replace bearings
and bearing races as a set.
INSTALLING THE LOWER
BRACKET
1. Install: • Lower bearing "1"
Apply the lithium soap base grease
on the dust seal lip and bearing inner
circumference.
2. Install:
• Bearing race
• Upper bearing "1"
• Bearing race cover "2"
Apply the lithium soap base grease
on the bearing and bearing race cov-
er lip.
3. Install:• Lower bracket "1"
Apply the lithium soap base grease
on the bearing, the portion "a" and
thread of the steering stem.
4. Install:• Steering ring nut "1"
Install the steering nut with its
stepped side "a" facing downward.
Tighten the steering ring nut using
the steering nut wrench "2".
Refer to "CHECKING AND AD-
JUSTING THE STEERING
HEAD" section in the CHAPTER
3.
Steering nut wrench:
YU-33975/90890-01403
Steering ring nut:
7 Nm (0.7 m•kg, 5.1 ft•
lb)

5-30
STEERING
5. Check the steering stem by turn-ing it lock to lock. If there is any
binding, remove the steering stem
assembly and inspect the steer-
ing bearings.
6. Install: • Washer "1"
7. Install: • Front fork "1"
• Upper bracket "2"
• Temporarily tighten the pinch bolts (lower bracket).
• Do not tighten the pinch bolts (up- per bracket) yet.
8. Install:
• Steering stem nut "1"
Apply the lithium soap base grease
on the contact surface of the steering
stem nut when installing.
9. After tightening the nut, check the steering for smooth movement. If
not, adjust the steering by loosen-
ing the steering ring nut little by lit-
tle.
10. Adjust: • Front fork top end "a"
11. Tighten: • Pinch bolt (upper bracket) "1"
• Pinch bolt (lower bracket) "2"
Tighten the lower bracket to speci-
fied torque. If to rqued too much, it
may cause the front fork to mal-
function.
Steering stem nut: 145 Nm (14.5 m•kg, 105
ft•lb)
Front fork top end (stan-
dard) "a":5 mm (0.20 in)
Pinch bolt (upper brack-
et): 21 Nm (2.1 m•kg, 15
ft•lb)
Pinch bolt (lower brack-
et): 21 Nm (2.1 m•kg, 15
ft•lb)

5-31
SWINGARM
SWINGARM
REMOVING THE SWINGARMOrder Part name Q'ty Remarks Hold the machine by placing the suitable stand
under the engine. Refer to "HANDLING NOTE".
Brake hose holder Refer to "FRONT BRAKE AND REAR
BRAKE" section.
Rear brake caliper Refer to "FRONT BRAKE AND REAR
BRAKE" section.
Bolt (brake pedal) Shift the brake pedal backward.
Drive chain
1 Drive chain support 1
2 Lower chain tensioner 1
3 Bolt (rear shock absorber-relay arm) 1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1

5-32
SWINGARM
DISASSEMBLING THE SWINGARMOrder Part name Q'ty Remarks1 Relay arm 1
2 Connecting rod 1
3 Collar 2
4 Oil seal 2
5 Thrust bearing 2
6 Bushing 2
7 Oil seal 8
8 Bearing 10 Refer to removal section.

5-33
SWINGARM
HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
REMOVING THE BEARING
1. Remove:• Bearing "1"
Remove the bearing by pressing its
outer race.
CHECKING THE SWINGARM
1. Inspect:• Bearing "1"
• Bushing "2"
Free play exists/unsmooth revolu-
tion/rust →Replace bearing and
bushing as a set.
2. Inspect: • Oil seal "3"Damage →Replace.
CHECKING THE RELAY ARM
1. 5294Inspect: • Bearing "1"
•Collar "2"
Free play exists/unsmooth revolu-
tion/rust → Replace bearing and
collar as a set.
2. Inspect: • Oil seal "3"Damage →Replace. CHECKING THE CONNECTING
ROD
1. Inspect:
•Bearing "1"
• Collar "2"Free play exists/unsmooth revolu-
tion/rust → Replace bearing and
collar as a set.
2. Inspect: • Oil seal "3"
Damage →Replace.
INSTALLING THE BEARING AND
OIL SEAL
1. Install: •Bearing "1"
• Oil seal "2"To swingarm.
• Apply the molybdenum disulfide
grease on the bearing when install-
ing.
• Install the bearing by pressing it on
the side having the manufacture's
marks or numbers.
• First install the outer and then the
inner bearings to a specified depth
from inside.
2. Install: • Bearing "1"
• Washer "2"
• Oil seal "3"To relay arm.
• Apply the molybdenum disulfide grease on the bearing when install-
ing.
• Install the bearing by pressing it on the side having the manufacture's
marks or numbers.
• Apply the molybdenum disulfide grease on the washer.
3. Install:• Bearing "1"
• Oil seal "2"To connecting rod.
• Apply the molybdenum disulfide grease on the bearing when install-
ing.
• Install the bearing by pressing it on the side having the manufacture's
marks or numbers.
Installed depth of bear-
ings:
Outer "a": Zero mm
(Zero in)
Inner "b": 6.5 mm (0.26
in)
Installed depth of bear-
ings "a": Zero mm (Zero in)
Installed depth of bear-
ings "a": Zero mm (Zero in)