2010 YAMAHA WR 250F Owners Manual

3-14
ENGINE
4. Clean:• Air filter elementClean them with solvent.
After cleaning, remo ve the remaining
solvent by squeezing the element.
• Do not twist the element when squeezing the element.
• Leaving too much of solvent in
the element may result in poor
starting.
5. Inspect:• Air filter elementDamage →Replace.
6. Apply: • Foam-air-filter oil or equivalent oil to the element
• Squeeze out the excess oil. Ele-
ment should be wet but not drip-
ping.
• Wipe off the oil left on the element
surface using a clean dry cloth. (Ex-
cess oil in the element may ad-
versely affect engine starting.)
7. Install:• Air filter guide "1"
• Align the projection "a" on filter
guide with the hole "b" in air filter el-
ement.
• Apply the lithium soap base grease
on the matching surface "c" on air
filter element.
8. Install:• Air filter element "1"
Align the projection "a" on filter guide
with the hole "b" in air filter case.
9. Hook:• Binder "1"
Hook the binder "1" so that it contacts
the filter guide projections "a".
CHECKING THE ENGINE OIL
LEVEL
1. Start the engine, warm it up for several minutes, and then turn off
the engine and wait for five min-
utes.
2. Place the machine on a level
place and hold it up on upright po-
sition by placing the suitable
stand under the engine.
3. Inspect: • Oil levelOil should be up to the full level in
the check window "1".
Level check window is not full. →
Add 0.2 L (0.18 Imp qt, 0.21 US
qt) of oil.
• Engine oil also lubricates the
clutch and the wrong oil types or
additives could cause clutch
slippage. Therefore, do not add
any chemical additives or use en-
gine oils with a grade of CD or
higher and do not use oils la-
beled "ENERGY CONSERVING
II".
• Do not allow fore ign materials to
enter the crankcase.
4. Install: • Oil tank cap
5. Start the engine and let it warm up for several minutes.
6. Turn off the engine and inspect
the oil level once again.
Wait a few minutes until the oil settles
before inspecting the oil level.
CHANGING THE ENGINE OIL
1. Start the engine and warm it up for several minutes, and then turn
off the engine and wait for five
minute.
2. Place the machine on a level place and hold it on upright posi-
tion by placing the suitable stand
under the engine.
3. Place a suitable container under
the engine.
4. Remove: • Engine guard "1"
• Bolt (oil tank) "2"
• Washer "3"
• Oil filler cap "4"
• Oil tank drain bolt "5"
• Crankcase oil drain bolt "6"
• Oil filter element drain bolt "7"
Drain the crankcase and oil tank
of its oil.
Recommended brand:
YAMALUBE
Recommended engine
oil type SAE 10W-30, SAE 10W-
40, SAE 10W-50, SAE
15W-40, SAE 20W-40 or
SAE 20W-50
Recommended engine
oil grade API service SG type or
higher, JASO standard
MA

3-15
ENGINE
5. Remove:• Oil hose clamp "1"
• Bolt (oil hose)
• Oil hose "2"
• Oil strainer "3"
6. Inspect: • Oil strainerClogged →Blow.
7. If the oil filter is to be replaced dur-
ing this oil change, remove the fol-
lowing parts and reinstall them.
Replacement steps:
a. Remove the oil filter element cov-er "1" and oil filter element "2".
b. Check the O-rings "3", if cracked or damaged, replace them with a
new one.
c. Install the oil filter element and oil filter element cover.
8. Install:
• O-ring "1" • Oil strainer "2"
• Oil hose
• Bolt (oil hose)
• Oil hose clamp
9. Install: • Copper washer
• Oil filter element drain bolt
• Crankcase oil drain bolt
• Oil tank drain bolt
• Engine guard
10. Fill: • Engine oil 11. Check:
• Oil leakage
12. Install: • Oil filler cap
• Washer (oil tank)
• Bolt (oil tank)
13. Check: • Engine oil level
CHECKING THE OIL PRESSURE
1. Check: • Oil pressure
Checking steps:
a. Slightly loosen the oil pressure check bolt "1".
b. Start the engine and keep it idling
until oil starts to seep from the oil
pressure check bolt. If no oil
comes out after one minute, turn
the engine off so it will not seize.
c. Check oil passages and oil pump for damage or leakage.
d. Start the engine after solving the problem(s) and recheck the oil
pressure.
e. Tighten the oil pressure check bolt.
Oil filter element cover:10 Nm (1.0 m•kg, 7.2
ft•lb)
Oil strainer:
9 Nm (0.9 m•kg, 6.5
ft•lb)
Bolt (oil hose): 8 Nm (0.8 m•kg, 5.8
ft•lb)
Oil hose clamp: 2 Nm (0.2 m•kg, 1.4
ft•lb)
Oil filter element drain
bolt: 10 Nm (1.0 m•kg, 7.2
ft•lb)
Crankcase oil drain bolt: 20 Nm (2.0 m•kg, 14
ft•lb)
Oil tank drain bolt: 18 Nm (1.8 m•kg, 13
ft•lb)
Engine guard: 7 Nm (0.7 m•kg, 5.1
ft•lb)
Oil quantity: Periodic oil change:
1.1 L (0.97 Imp qt, 1.16
US qt)
With oil filter replace-
ment: 1.2 L (1.06 Imp qt, 1.27
US qt)
Total amount: 1.4 L (1.23 Imp qt, 1.48
US qt)
Bolt (oil tank): 7 Nm (0.7 m•kg, 5.1
ft•lb)
Oil pressure check bolt: 10 Nm (1.0 m•kg, 7.2
ft•lb)

3-16
ENGINE
ADJUSTING THE PILOT SCREW
(For EUROPE)
1. Adjust:• Pilot screw "1"
Adjustment steps:
To optimize the fuel flow at a smaller
throttle opening, each machine's pilot
screw has been individually set at the
factory. Before adjusting the pilot
screw, turn it in fully and count the
number of turns. Record this number
as the factory-set number of turns
out.
a. Turn in the pilot screw until it is lightly seated.
b. Turn out the pilot screw by the factory-set number of turns.
ADJUSTING THE ENGINE IDLING
SPEED
1. Start the engine and thoroughly warm it up.
2. Adjust: • Engine idling speed
Adjustment steps:
a. Turn the throttle stop screw "1" until the specified engine idling
speed.
Using a digital engine tachometer for
idle speed adjustment, detect the en-
gine idling speed by bringing the
sensing element "c" of the engine ta-
chometer close to the ignition coil "2".
ADJUSTING THE VALVE
CLEARANCE
This section is intended for those who
have basic knowledge and skill con-
cerning the servicing of Yamaha mo-
torcycles (e.g., Yamaha dealers,
service engineers, etc.) Those who
have little knowledge and skill con-
cerning servicing are requested not to
undertake inspection, adjustment,
disassembly, or reassembly only by
reference to this manual. It may lead
to servicing trouble and mechanical
damage.
• The valve clearance should be ad-justed when the engine is cool to
the touch.
• The piston must be at Top Dead Center (T.D.C.) on compression
stroke to check or adjust the valve
clearance.
1. Remove:•Seat
•Fuel tank
Refer to "SEAT, FUEL TANK
AND SIDE COVERS" section.
2. Drain:
• CoolantRefer to "CHANGING THE
COOLANT" section.
3. Remove: • Right radiatorRight to "RADIATOR" section in
the CHAPTER 5.
• Carburetor Refer to "CARBU RETOR" section
in the CHAPTER 5.
• Spark plug
• Upper engine bracket
• Cylinder head cover Refer to "CAMSHAFTS" section
in the CHAPTER 5. 4. Remove:
• Timing mark accessing screw "1"
• Crankshaft end accessing screw "2"
• O-ring
5. Check: • Valve clearanceOut of specification →Adjust.
Checking steps:
a. Turn the crankshaft counterclock-
wise with a wrench.
b. Align the T.D.C. mark "a" on the
rotor with the align mark "b" on the
crankcase cover when piston is at
T.D.C. on compression stroke.
In order to be sure t hat the piston is at
Top Dead Center, the punch mark "c"
on the exhaust camshaft and the
punch mark "d" on the intake cam-
shaft must align with the cylinder
head surface, as shown in the illustra-
tion.
c. Measure the valve clearance "e" using a feeler gauge "1".
Record the measured reading if the
clearance is incorrect.
Pilot screw (example):2 turns out
To increase idle speed →Turn the
throttle stop screw "1" in "a".
To decrease idle speed →Turn the
throttle stop screw "1" out "b".
Engine idling speed:1,750–1,950 r/min
Valve clearance (cold):
Intake valve:0.10–0.15 mm
(0.0039–0.0059 in)
Exhaust valve:0.17–0.22 mm
(0.0067–0.0087 in)

3-17
ENGINE
6. Adjust:• Valve clearance
Adjustment steps:
a. Remove the camshaft (intake and exhaust).
Refer to "CAMSHAFTS" section
in the CHAPTER 5.
b. Remove the valve lifters "1" and the pads "2".
• Place a rag in the timing chain
space to prevent pads from falling
into the crankcase.
• Identity each valve lifter and pad
position very carefully so that they
can be reinstalled in their original
place.
c. Select the proper pad using the pad selecting table.
The thickness "a" of each pad is indi-
cated in hundredths of millimeters on
the pad upper surface.
d. Round off the last digit of the in-stalled pad number to the nearest
increment.
EXAMPLE:
Installed pad number = 148
Rounded off value = 150
Pads can only be selected in 0.05
mm increments.
e. Locate the rounded-off value and the measured valve clearance in
the chart "PAD SELECTION TA-
BLE". The field where these two
coordinates intersect shows the
new pad number to use.
Use the new pad number only as a
guide when verifying the valve clear-
ance adjustment.
f. Install the new pads "3" and the
valve lifters "4".
• Apply the engine oil on the valve lift-ers.
• Apply the molybdenum disulfide oil
on the valve stem ends.
• Valve lifter must turn smoothly
when rotated with a finger.
• Be careful to reinstall valve lifters and pads in their original place.
g. Install the camshafts (exhaust
and intake).
Refer to "CAMSHAFTS" section
in the CHAPTER 5.
Pad range Pad Availabili-
ty: 25 incre-
ments
No.
120– No.
240 1.20
mm– 2.40
mm Pads are avail-
able in 0.05 mm increments
Last digit of pad number Rounded valve
0, 1 or 2 0
4, 5 or 6 5
8 or 9 10

3-18
ENGINE
INTAKE
EXHAUST
MEASURED
CLEARANCE INSTALLED PAD NUMBER
120 125 130 135 140 145 150 155 160 165 170
175 180 185 190 195 200 205 210 215 220 225 230 235 240
0.00 - 0.04 120 125 130 135 140 145 150 155
160165 170 175 180 185 190 195 200 205 210 215 220 225 230
0.05 - 0.09
120 125 130 135 140 145 150 155 160 165170 175 180 185 190 195 200 205 210 215 220 225 230 235
0.10 - 0.15
STANDARD CLEARANCE
0.16 - 0.20125130135140145150155160165170175180 185 190 195 200 205 210 215 220 225 230 235240
0.21 - 0.25130135140145150155160165170175180185 190 195 200 205 210 215 220 225 230 235240
0.26 - 0.30 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.31 - 0.35 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.36 - 0.40 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.41 - 0.45 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.46 - 0.50 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.51 - 0.55 160 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.56 - 0.60 165 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.61 - 0.65 170 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.66 - 0.70 175 180 185 190 195 200 205 210 215 220 225 230 235240
0.71 - 0.75 180 185 190 195 200 205 210 215 220 225 230 235240
0.76 - 0.80 185 190 195 200 205 210 215 220 225 230 235240VALVE CLEARANCE (cold): 0.10 - 0.15 mm
Example: Installed is 175 Measured clearance is 0.23 mm
Replace 175 pad with 185 pad Pad number: (example)
Pad No. 175 = 1.75 mm
Pad No. 185 = 1.85 mm0.81 - 0.85 190 195 200 205 210 215 220 225 230 235240
0.86 - 0.90 195 200 205 210 215 220 225 230 235240
0.91 - 0.95 200 205 210 215 220 225 230 235240
0.96 - 1.00 205 210 215 220 225 230 235240
1.01 - 1.05 210 215 220 225 230 235240
1.06 - 1.10 215 220 225 230 235240
1.11 - 1.15 220 225 230 235240
1.16 - 1.20 225 230 235240
1.21 - 1.25 230 235240
1.26 - 1.30 235240
1.31 - 1.35 240
MEASURED
CLEARANCE INSTALLED PAD NUMBER
120 125 130 135 140 145 150 155 160 165 170
175 180 185 190 195 200 205 210 215 220 225 230 235 240
0.00 - 0.04 120 125 130 135 140 145 150 155
160 165 170 175 180 185 190 195 200 205 210 215 220 225
0.05 - 0.09
120 125 130 135 140 145 150 155 160165 170 175 180 185 190 195 200 205 210 215 220 225 230
0.10 - 0.16
120125130135140145150155160165170 175 180 185 190 195 200 205 210 215 220 225230235
0.17 - 0.22STANDARD CLEARANCE
0.23 - 0.25 125 130 135 140 145 150 155 160 165 170 175
180 185 190 195 200 205 210 215 220 225230235240
0.26 - 0.30130135140145150155160165170175180185 190 195 200 205 210 215 220 225230235240
0.31 - 0.35 135 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.36 - 0.40 140 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.41 - 0.45 145 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.46 - 0.50 150 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.51 - 0.55 155 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.56 - 0.60 160 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.61 - 0.65 165 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.66 - 0.70 170 175 180 185 190 195 200 205 210 215 220 225230235240
0.71 - 0.75 175 180 185 190 195 200 205 210 215 220 225230235240
0.76 - 0.80 180 185 190 195 200 205 210 215 220 225230235240
0.81 - 0.85 185 190 195 200 205 210 215 220 225230235240
VALVE CLEARANCE (cold): 0.17 - 0.22 mm
Example: Installed is 175 Measured clearance is 0.27 mm
Replace 175 pad with 185 pad Pad number: (example)
Pad No. 175 = 1.75 mm
Pad No. 185 = 1.85 mm0.86 - 0.90 190 195 200 205 210 215 220 225230235240
0.91 - 0.95 195 200 205 210 215 220 225230235240
0.96 - 1.00 200 205 210 215 220 225230235240
1.01 - 1.05 205 210 215 220 225230235240
1.06 - 1.10 210 215 220 225230235240
1.11 - 1.15 215 220 225230235240
1.16 - 1.20 220 225230235240
1.21 - 1.25 225230235240
1.26 - 1.30 230235240
1.31 - 1.35 235240
1.36 - 1.40 240

3-19
CHASSIS
CLEANING THE SPARK
ARRESTER (For USA)
• Be sure the exhaust pipe and si-lencer are cool before cleaning
the spark arrester.
• Do not start the engine when cleaning the exhaust system.
1. Remove:• Screw (silencer cap) "1"
2. Remove: • Bolt (spark arrester) "1"
3. Remove: • Tail pipe "1"
• Gasket (tail pipe) "2"
• Spark arrester "3"Pull the spark arrester out of the
silencer.
• Gasket (spark arrester) "4"
4. Clean: • Spark arrester
Tap the spark arrester lightly,
then use a wire brush to remove
any carbon deposits.
5. Install: • Gasket (spark arrester)
• Spark arresterInsert the spark arrester into the
silencer and align the bolt holes.
• Gasket (tail pipe)
• Bolt (spark arrester) 6. Install:
• Silencer cap
First tighten the two screws "a" locat-
ed horizontally apart, and then tighten
the others.
CHASSIS
BLEEDING THE HYDRAULIC
BRAKE SYSTEM
Bleed the brake system if:
• The system has been disassem-bled.
• A brake hose has been loosened
or removed.
• The brake fluid is very low.
• The brake operation is faulty.
A dangerous loss of braking per-
formance may occur if the brake
system is not properly bled.
1. Remove: • Brake master cylinder cap
• Diaphragm
• Reservoir float (front brake)
• Protector (rear brake)
2. Bleed: •Brake fluid
Air bleeding steps:
a. Add proper brake fluid to the res- ervoir.
b. Install the diaphragm. Be careful not to spill any fluid or allow the
reservoir to overflow.
c. Connect the clear plastic tube "2" tightly to the caliper bleed screw
"1". A. Front
B. Rear
d. Place the other end of the tube
into a container.
e. Slowly apply the brake lever or pedal several times.
f. Pull the lever in or push down on
the pedal. Hold the lever or pedal
in position.
g. Loosen the bleed screw and allow
the lever or pedal to travel to-
wards its limit.
h. Tighten the bleed screw when the
lever or pedal limit has been
reached; then release the lever or
pedal.
i. Repeat steps (e) to (h) until of the air bubbles have been removed
from the system.
If bleeding is difficult, it may be nec-
essary to let the brake fluid system
stabilize for a few hours. Repeat the
bleeding procedure when the tiny
bubbles in the system have disap-
peared.
j. Add brake fluid to the level line on the reservoir.
Check the operation of the brake
after bleeding the brake system.
3. Install:
• Protector (rear brake)
• Reservoir float (front brake)
• Diaphragm
• Brake master cylinder cap
Bolt (spark arrester): 7 Nm (0.7 m•kg, 5.1
ft•lb)
Silencer cap:5 Nm (0.5 m•kg, 3.6
ft•lb)
Bleed screw:
6 Nm (0.6 m•kg, 4.3
ft•lb)

3-20
CHASSIS
ADJUSTING THE FRONT BRAKE
1. Check:• Brake lever position "a"
2. Remove: • Brake lever cover
3. Adjust: • Brake lever position
Brake lever position adjustment
steps:
a. Loosen the locknut "1".
b. Turn the adjusting bolt "2" until the lever position "a" is within speci-
fied position.
c. Tighten the locknut.
Be sure to tighten the locknut, as it
will cause poor brake perfor-
mance.
4. Install: • Brake lever cover ADJUSTING THE REAR BRAKE
1. Check:
• Brake pedal height "a"Out of specification →Adjust.
2. Adjust: • Brake pedal height
Pedal height adjustment steps:
a. Loosen the locknut "1".
b. Turn the adjusting nut "2" until the pedal height "a" is within specified
height.
c. Tighten the locknut.
• Adjust the pedal height between the maximum "A" and the mini-
mum "B" as shown. (In this ad-
justment, the bolt "3" end "b"
should protrude out of the
threaded portion "4" but not be
less than 2 mm (0.08 in) "c" away
from the brake pedal "5").
• After the pedal height adjust- ment, make sure that the rear
brake does not drag.
CHECKING AND REPLACING THE
FRONT BRAKE PADS
1. Inspect:• Brake pad thickness "a"
Out of specification →Replace as
a set.
2. Replace: • Brake pad
Brake pad replacement steps:
a. Remove the pad pin plug "1".
b. Loosen the pad pin "2".
c. Remove the brake caliper "3" from the front fork.
d. Remove the pad pin and brake pads "4".
Brake lever position "a":
Standard posi- tion Extent of ad-
justment
95 mm (3.74 in) 76–97 mm
(2.99–3.82 in)
Locknut: 5 Nm (0.5 m •kg, 3.6
ft•lb)
Brake pedal height "a":
10 mm (0.39 in)
Brake pad thickness: 4.4 mm (0.17 in)
: 1.0 mm (0.04
in)

3-21
CHASSIS
e. Connect the transparent hose "5" to the bleed screw "6" and place
the suitable container under its
end.
f. Loosen the bleed screw and push the brake caliper piston in.
Do not reuse the drained brake flu-
id.
g. Tighten the bleed screw.
h. Install the brake pads "7" and pad pin.
• Install the brake pads with their pro-
jections "a" into the brake caliper re-
cesses "b".
• Temporarily tighten the pad pin at
this point.
i. Install the brake caliper "8" and tighten the pad pin "9". j. Install the pad pin plug "10".
3. Inspect:
• Brake fluid levelRefer to "CHECKING THE
BRAKE FLUID LEVEL" section.
4. Check: • Brake lever operationA softy or spongy feeling →Bleed
brake system.
Refer to "BL EEDING THE HY-
DRAULIC BRAKE SYSTEM" sec-
tion.
CHECKING AND REPLACING THE
REAR BRAKE PADS
1. Inspect: • Brake pad thickness "a"Out of specification →Replace as
a set.
2. Replace: •Brake pad
Brake pad replacement steps:
a. Remove the protector "1" and pad pin plug "2".
b. Loosen the pad pin "3". c. Remove the rear wheel "4" and
brake caliper "5".
Refer to "FRONT WHEEL AND
REAR WHEEL" section in the
CHAPTER 6.
d. Remove the pad pin "6" and brake pads "7".
e. Connect the transparent hose "8" to the bleed screw "9" and place
the suitable container under its
end.
f. Loosen the bleed screw and push the brake caliper piston in.
Do not reuse the drained brake flu-
id.
g. Tighten the bleed screw.
h. Install the brake pad "10" and pad pin "11".
• Install the brake pads with their pro-jections "a" into the brake caliper re-
cesses "b".
• Temporarily tighten the pad pin at
this point.
Bleed screw: 6 Nm (0.6 m•kg, 4.3
ft•lb)
Bolt (brake caliper): 23 Nm (2.3 m•kg, 17
ft•lb)
Pad pin:
18 Nm (1.8 m•kg, 13
ft•lb)
Pad pin plug:3 Nm (0.3 m•kg, 2.2
ft•lb)
Brake pad thickness: 6.4 mm (0.25 in)
: 1.0 mm (0.04
in)
Bleed screw: 6 Nm (0.6 m•kg, 4.3
ft•lb)