2016 YAMAHA YZ250F ECU

HANDLEBAR
4-33
EAS1SM9160REMOVING THE HANDLEBAR
1. Stand the vehicle upright on a level surface.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Grip “1”
TIP
Blow in compressed air between the handlebar
or tube guide and the grip. Then remove the
grip which has become loose.
EAS1SM9161CHECKING THE HANDLEBAR
1. Check:
• Handlebar
Bends/cracks/damage  Replace.
EWA
WARNING
Do not attempt to straighten a bent handle-
bar as this may dangerously weaken it.
EAS1SM9162INSTALLING THE HANDLEBAR
1. Stand the vehicle upright on a level surface.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Install:
• Damper “1”
• Handlebar “2” (temporarily)
• Upper handlebar holders “3”
• Upper handlebar holders “4”
TIP
• Install the lower handlebar holders with them
side having the greater distance “a” from the
mounting bolt center facing forward.
• Installing the lower handlebar holders in the
reverse direction allow the front-to-rear offset
amount of the handlebar position to be
changed.
• The upper handlebar holders should be in-
stalled with the punch marks “b” facing for-
ward.
• When installing the handlebar, make sure that
right and left marks “c” are in place identically
on both sides.
• Install the handlebar so that the projection “d”
of the upper handlebar holders is positioned
at the mark on the handlebar as shown.
ECA14250
NOTICE
• First, tighten the bolts on the front side of
the upper handlebar holder, and then on
the rear side.
• Turn the handlebar all the way to the left
and right. If there is any contact with the
fuel tank, adjust the handlebar position.
Upper handlebar holder bolt
28 Nm (2.8 m·kgf, 20 ft·lbf)
T R..
2
1
1
a

HANDLEBAR
4-34
3. Tighten:
• Lower handlebar holder nut4. Install:
• Handlebar grip “1”
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Slightly coat the handlebar left end with a
rubber adhesive.
b. Install the handlebar grip on the handlebar
by pressing the grip from the left side.
c. Wipe off any excess adhesive with a clean
cloth.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Install the handlebar grip to the handlebar so
that the line “a” between the two arrow marks
faces straight upward.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
5. Install:
• Handlebar grip “1”
• Handlebar grip “2”
• Handlebar grip “3”
•Clamp “4”
TIP
• The engine stop switch, the clutch lever, and
the clutch lever holder should be installed ac-
cording to the dimensions shown.
• Pass the engine stop switch lead through the
middle of the clutch lever holder. Lower handlebar holder nut
40 Nm (4.0 m·kgf, 29 ft·lbf)
3
4
T R..
Engine stop switch screw
0.5 Nm (0.05 m·kgf, 0.36 ft·lbf)
Clutch lever holder bolt
5 Nm (0.5 m·kgf, 3.6 ft·lbf)
T R..

FRONT FORK
4-39
EAS1SM9164REMOVING THE FRONT FORK LEGS
1. Use a suitable stand to raise the front wheel
off the ground.
EWAWARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Record the adjusting screw setting position be-
fore loosening the adjuster and the base valve.
2. Loosen:
• Upper bracket pinch bolts
• Damper assembly
• Lower bracket pinch bolts
EWAWARNING
Before loosening the upper and lower
bracket pinch bolts, support the front fork
leg.
TIP
Before removing the front fork leg from the ve-
hicle, loosen the damper assembly “1” with the
cap bolt ring wrench “2”.
3. Remove:
• Front fork leg (s)
EAS1SM9165DISASSEMBLING THE FRONT FORK LEGS
1. Drain:
• Fork oil
2. Remove:
• Adjuster “1”
(from the inner tube)
TIP
• While compressing the inner tube “2”, set the
cap bolt ring wrench “4” between the inner
tube and locknut “3”.
• Hold the locknut and remove the adjuster.
ECA
NOTICE
Do not scratch the inner tube.
3. Remove:
• Dust seal “1”
• Oil seal clip “2”
(with a flat-head screwdriver)
ECANOTICE
Do not scratch the inner tube.
4. Remove:
• Inner tube “1”
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Push in slowly “a” the inner tube just before
it bottoms out and then pull it back quickly
“b”.
b. Repeat this step until the inner tube can be
pulled out from the outer tube.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
Cap bolt ring wrench
90890-01501
YM-01501
12
Cap bolt ring wrench
90890-01501
YM-01501
1
234
1
2

STEERING HEAD
4-50
EAS1SM9170REMOVING THE LOWER BRACKET
1. Use a suitable stand to raise the front wheel
off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Rng nut “1”
TIP
Remove the ring nut with the steering nut
wrench “2”.
EWA
WARNING
Securely support the lower bracket so that
there is no danger of it falling.
EAS1SM9171CHECKING THE STEERING HEAD
1. Wash with kerosene:
• Bearing
• Bearing races
2. Check:
• Bearing
• Bearing races
Damage/pitting  Replace.
3. Replace:
• Bearing
• Bearing races
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the bearing race from the steering
head pipe with a long rod “1” and a hammer.
b. Remove the bearing race from the lower
bracket with a chisel “2” and a hammer.
c. Install a new bearing race.
ECA
NOTICE
If the bearing race is not installed properly,
the steering head pipe could be damaged.
TIP
Always replace the bearing and the bearing
race as a set.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
4. Check:
• Upper bracket
• Lower bracket
(along with the steering stem)
Bends/cracks/damage  Replace.
EAS1SM9172INSTALLING THE STEERING HEAD
1. Install:
• Lower bearing “1”
TIP
Apply the lithium soap base grease on the dust
seal lip and bearing inner circumference. Steering nut wrench
90890-01403
Exhaust flange nut wrench
YU-A9472

REAR SHOCK ABSORBER ASSEMBLY
4-56
EAS1SM9174HANDLING THE REAR SHOCK ABSORBEREWAWARNING
This rear shock absorber contains highly
compressed nitrogen gas. Before handling
the rear shock absorber, read and make
sure that you understand the following in-
formation. The manufacturer cannot be held
responsible for property damage or person-
al injury that may result from improper han-
dling of the rear shock absorber.
• Do not tamper or attempt to open the rear
shock absorber.
• Do not subject the rear shock absorber to
an open flame or any other source of high
heat. High heat can cause an explosion
due to excessive gas pressure.
• Do not deform or damage the rear shock
absorber in any way. Rear shock absorber
damage will result in poor damping perfor-
mance.
TIP
A break-in is required up to about 50 km of run-
ning.
EAS1SM9175DISPOSING OF A REAR SHOCK ABSORB-
ER
Before disposing the rear shock absorber, be
sure to extract the nitrogen gas from valve “1”.
EWA
WARNING
• Wear protective glasses to prevent your
eyes from damage due to possible gas or
metal chips scattered.
• To dispose of a damaged or a worn-out
rear shock absorber, take the unit to your
Yamaha dealer for this disposal proce-
dure.
EAS1SM9176REMOVING THE REAR SHOCK ABSORBER
ASSEMBLY
1. Use a suitable stand to raise the rear wheel
off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Rear shock absorber assembly lower bolt
“1”
TIP
While removing the rear shock absorber as-
sembly lower bolt, hold the swingarm so that it
does not drop down.
3. Remove:
• Rear shock absorber assembly upper bolt
• Rear shock absorber assembly
EAS1SM9177REMOVING THE BEARING
1. Remove:
• Stopper ring (upper bearing) “1”
TIP
Press in the bearing while pressing its outer
race and remove the stopper ring.
1
1

SWINGARM
4-61
EAS1SM9183REMOVING THE SWINGARM
1. Use a suitable stand to raise the rear wheel
off the ground.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Measure:
• Swingarm side play
• Swingarm vertical movement
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Measure the tightening torque of the pivot
shaft nut.
b. Measure the swingarm side play “a” by mov-
ing the swingarm from side to side.
c. If the swingarm side play is out of specifica-
tion, check the spacers, the bearings, and
the collars.
d. Check the swingarm vertical movement “b”
by moving the swingarm up and down.
If swingarm vertical movement is not smooth
or if there is binding, check the spacers, the
bearings, and the collars.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS1SM9184REMOVING THE BEARING
1. Remove:
• Bearing “1”
TIP
Remove the bearing by pressing its outer race.
EAS1SM9185CHECKING THE SWINGARM
1. Check:
• Swingarm
Bends/cracks/damage  Replace.
2. Check:
• Pivot shaft
Roll the pivot shaft on a flat surface.
Bends  Replace.
EWA
WARNING
Do not attempt to straighten a bent pivot
shaft.
3. Wash with kerosene:
• Pivot shaft
• Spacers
•Collars
• Bearing
4. Check:
• Oil seals
Damage  Replace.
• Bearing
• Spacers
Free play exists/unsmooth revolution/rust 
Replace bearing and bushing as a set. Pivot shaft nut
85 Nm (8.5 m·kgf, 61 ft·lbf)
Swingarm end free play limit (ra-
dial)
1.0 mm (0.04 in)
T R..

CHAIN DRIVE
4-64
EAS1SM9188REMOVING THE DRIVE CHAIN
1. Use a suitable stand to raise the rear wheel
off the ground.
EWA13120
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
• Joint clip
• Drive chain joint “1”
• Drive chain “2”
EAS1SM9189CHECKING THE DRIVE CHAIN
1. Measure:
• 15-link section of the drive chain
Out of specification  Replace the drive
chain.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Measure the length “a” between the inner
sides of the pins and the length “b” between
the outer sides of the pins on a 15-link sec-
tion of the drive chain as shown in the illus-
tration.
b. Calculate the length “c” of the 15-link section
of the drive chain using the following formu-
la.
Drive chain 15-link section length “c” =
(length “a” between pin inner sides + length
“b” between pin outer sides)/2
TIP
• When measuring a 15-link section of the drive
chain, make sure that the drive chain is taut.
• Perform this procedure 2–3 times, at a differ-
ent location each time.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
2. Check:
•Drive chain
Stiffness  Clean, lubricate, or replace.
3. Clean:
•Drive chain
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Wipe the drive chain with a clean cloth.
b. Put the drive chain in kerosene and remove
any remaining dirt.
c. Remove the drive chain from the kerosene
and completely dry it.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
15-link length limit
242.9 mm (9.56 in)

ENGINE REMOVAL
5-3
Removing the electronic parts
Order Part name Q’ty Remarks
Use a suitable stand to raise the front wheel
off the ground.
Seat Refer to “GENERAL CHASSIS” on page 4-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 4-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 4-1.
Fuel tank Refer to “FUEL TANK” on page 7-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Condenser 1
5 Neutral switch 1
6 AC magneto coupler 1 Disconnect.
7 Crankshaft position sensor coupler 1 Disconnect.
8 Coolant temperature sensor coupler 1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
8 3
7
6
154
2
LT
New
LS