2015 YAMAHA WR 250F ECU

STEERING HEAD
5-54
EAS2GB2206REMOVING 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.
EAS2GB2207CHECKING THE STEERING HEAD
1. Wash with kerosene:
• Bearing
• Bearing races
2. Check:
• Bearing
• Bearing races
Damage/pitting  Replace.
3. Replace:
• Bearing
• Bearing races
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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.
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4. Check:
• Upper bracket
• Lower bracket
(along with the steering stem)
Bends/cracks/damage  Replace.
EAS2GB2208INSTALLING THE STEERING HEAD
1. Install:
• Lower bearing “1”
TIP
Apply the lithium-soap-based grease on the
dust seal lip and bearing inner circumference.
2. Install:
• Bearing races
• Upper bearing “1”
• Bearing race cover “2” Steering nut wrench
90890-01403
Exhaust flange nut wrench
YU-A9472

REAR SHOCK ABSORBER ASSEMBLY
5-60
EAS2GB2210HANDLING THE REAR SHOCK ABSORBEREWA
WARNING
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.
EAS2GB2211DISPOSING 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.
EAS2GB2212
REMOVING 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
EAS2GB2213REMOVING 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
5-65
EAS2GB2219REMOVING 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
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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.
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EAS2GB2220REMOVING THE BEARING
1. Remove:
• Bearing “1”
TIP
Remove the bearing by pressing its outer race.
EAS2GB2221CHECKING 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
5-68
EAS23420REMOVING THE DRIVE CHAIN
1. Stand the vehicle on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
TIP
Place the vehicle on a suitable stand so that the
rear wheel is elevated.
2. Remove:
•Drive chain
TIP
Cut the drive chain with the drive chain cut &
rivet tool. (Use goods on the market)
EAS23441CHECKING THE DRIVE CHAIN
1. Measure:
• 15-link section of the drive chain
Out of specification  Replace the drive
chain.
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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.
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2. Check:
•Drive chain
Stiffness  Clean, lubricate, or replace.
3. Clean:
•Drive chain
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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.
ECA
NOTICE
• This vehicle has a drive chain with small
rubber O-rings “1” between the drive
chain side plates. Never use high-pressure
water or air, steam, gasoline, certain sol-
vents (e.g., benzine), or a coarse brush to
clean the drive chain. High-pressure meth-
ods could force dirt or water into the drive
chain’s internals, and solvents will deteri-
orate the O-rings. A coarse brush can also
damage the O-rings. Therefore, use only
kerosene to clean the drive chain.
• Do not soak the drive chain in kerosene for
more than ten minutes, otherwise the O-
rings can be damaged. 15-link length limit
239.3 mm (9.42 in)

ENGINE REMOVAL
6-3
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 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left / right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
Air filter case cover
1 Rectifier/regulator 1
2ECU 1
3 Ignition coil 1
4 Neutral switch 1
5 AC magneto coupler 1 Disconnect.
6 Crankshaft position sensor coupler 1 Disconnect.
7 Coolant temperature sensor coupler 1 Disconnect.
For installation, reverse the removal proce-
dure.
T.R.
T.R.
T.R.T.R.
7 3
6
5
142
LT
New
LS

FUEL TANK
8-4
EAS2GB2346REMOVING THE FUEL SENDER
1. Remove:
• Fuel sender
ECA
NOTICE
Do not drop the fuel sender or give it a
strong shock.
EAS2GB2347CHECKING THE FUEL SENDER
1. Disconnect:
• Fuel pump coupler
• Fuel sender coupler
(from the wire harness)
2. Disconnect:
• Starter motor lead
(from starter relay)
3. Remove:
• Fuel tank
4. Remove:
• Fuel sender
(from the fuel tank)
5. Connect:
• Fuel sender coupler
6. Push the start switch.
7. Check:
• Fuel level warning light
Out of specification  Replace the fuel
sender.
EAS2GB2348INSTALLING THE FUEL SENDER
1. Install:
• Fuel sender gasket
• Fuel sender
TIP
• Do not damage the installation surfaces of the
fuel tank when installing the fuel sender.
• Always use a new fuel sender gasket.
• Install the fuel sender as shown in the illustra-
tion.
• When install the fuel sender, make sure that
the projection “a” faces the rear of the vehicle.
EAS2GB2349INSTALLING THE FUEL TANK
1. Install:
• Fuel tank
2. Connect:
• Fuel hose
ECA
NOTICE
• Connect the fuel hose securely, and check
that the orientation of the installed fuel
hose holder is correct.
• Take care not to kink or pinch the fuel
hose.
Fuel pump is atmosphere “A”
 Fuel level warning light is come on
Fuel pump is soaked in fuel “B”
Fuel level warning light is goes off
a
b
4 1
2
6
53
Fuel sender bolts
4.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
AB
New
T R..
a

FUEL TANK
8-5
TIP
• Insert the fuel hose into the fuel pipe securely
until you hear a “click”.
• Slide the fuel hose connector cover “1” at the
hose end in the direction of the arrow.
• Install the fuel hose connector holder “a”.
• Check that the fuel hose and the fuel pump
lead are routed through the guide on the cov-
er.
3. Connect:
• Fuel pump coupler
4. Install:
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GB2350CHECKING THE FUEL PRESSURE
1. Check:
• Fuel pressure
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a. Remove the side cover (left/right), the seat
and the air scoop (left/right).
Refer to “GENERAL CHASSIS” on page 5-
1.
b. Remove the fuel tank bolt and lift the fuel
tank.
c. Disconnect the fuel hose from the fuel
pump.
Refer to “REMOVING THE FUEL TANK” on
page 8-3.
EWA
WARNING
Cover the fuel hose connection with a cloth
when disconnecting it. This is because re-
sidual pressure in the fuel hose could cause
fuel to spurt out when the hose is removed.
ECA
NOTICE
Make sure that the fuel hose is disconnect-
ed by hand. Do not forcibly disconnect the
hose with tools.
d. Connect the pressure gauge “1” and the fuel
pressure adapter “2” to the fuel hose.
e. Start the engine.
f. Measure the fuel pressure.
Out of specification  Replace the fuel
pump.
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EAS2GB2351CHECKING THE DAMPER
1. Check:
• Damper 1 “1”
• Damper 2 “2”
• Damper 3 “3”
Wear/damage  Replace.
TIP
• Affix dampers 1 and 3 with the arrow on each
damper pointing outward.
• Affix the damper 2 with its projection “a” facing
the rear of the vehicle.
1
a
Pressure gauge
90890-03153
Pressure gauge
YU-03153
Fuel pressure adapter
90890-03186
Fuel pressure adapter
YM-03186
Fuel line pressure at idling
324.0 kPa (3.24 kgf/cm
2, 47.0
psi)
1
2

THROTTLE BODY
8-7
EAS2GB2353
THROTTLE BODY
Removing the throttle body
Order Part name Q’ty Remarks
Seat Refer to “GENERAL CHASSIS” on page 5-1.
Side cover (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Air scoop (left/right) Refer to “GENERAL CHASSIS” on page 5-1.
Fuel tank Refer to “FUEL TANK” on page 8-1.
ECU Refer to “ENGINE REMOVAL” on page 6-1.
Ignition coil Refer to “ENGINE REMOVAL” on page 6-1.
1 Intake air temperature sensor coupler 1 Disconnect.
2 Breather hose 3 1
3 Air filter case 1
4 Fuel injector coupler 1 Disconnect.
5 Intake air pressure sensor coupler 1 Disconnect.
6 Throttle position sensor coupler 1 Disconnect.
7 Throttle cable cover 1
8 Throttle cable 2
3
1
2
7
11
12
10
9
4
8
6
5
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
3.5 Nm (0.35 m kgf, 2.5 ft Ibf)T.R.
7 Nm (0.7 m kgf, 5.1 ft Ibf)T.R.
3.0 Nm (0.30 m kgf, 2.2 ft Ibf)T.R.
10 Nm (1.0 m kgf, 7.2 ft Ibf)T.R.