2001 YAMAHA WR 250F check engine

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EC350000
ENGINE
EC351011
COOLANT LEVEL INSPECTION
WARNING
Do not remove the radiator cap 1, drain
bolt and hoses when the engine and radia-
tor are hot. Scalding hot fluid and steam
may be blown out under pressure, which
could cause serious injury.
When the engine has cooled, place a thick
towel over the radiator cap, slowly rotate
the cap counterclockwise to the detent.
This procedure allows any residual pres-
sure to escape. When the hissing sound
has stopped, press down on the cap while
turning counterclockwise and remove it.
CAUTION:
Hard water or salt water is harmful to the
engine parts. You may use distilled water, if
you can’t get soft water.
1. Place the machine on a level place, and
hold it in an upright position.
2. Inspect:
lCoolant level
Coolant level should be between the
maximum a and minimum b marks.
Coolant level is below the “LOW” level
line ® Add soft water (tap water) up to
the proper level.
3. Start the engine and let it warm up for
several minutes.
4. Turn off the engine and check the coolant
level again.
NOTE:
Before checking the coolant level, wait a few
minutes until the coolant settles.
LOWFULLCOOLANT
a
b
COOLANT REPLACEMENT
WARNING
Do not remove the radiator cap when the
engine is hot.
ENGINE/COOLANT LEVEL INSPECTION/
COOLANT REPLACEMENT

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RADIATOR CAP INSPECTION
CAUTION:
lDo not mix more than one type of ethyl-
ene glycol antifreeze containing corro-
sion inhibitors for aluminum engine.
lDo not use water containing impurities or oil.
10. Install:
lRadiator cap
11. Fill:
lCoolant reservoir
Midway a between maximum and min-
imum marks on the tank.
12. Install:
lCoolant reservoir cap
13. Start the engine and let it warm up for
several minutes.
14. Turn off the engine and inspect the cool-
ant level.
Refer to “COOLANT LEVEL INSPEC-
TION” section.
NOTE:
Before checking the coolant level wait a few
minutes until the coolant settles.Handling notes of coolant:
The coolant is harmful so it should be han-
dled with special care.
WARNING
lWhen coolant splashes to your eye.
Thoroughly wash your eye with water
and see your doctor.
lWhen coolant splashes to your clothes.
Quickly wash it away with water and
then with soap.
lWhen coolant is swallowed.
Quickly make him vomit and take him
to a doctor.
LOWFULLCOOLANTa
EC355000
RADIATOR CAP INSPECTION
1. Inspect:
lSeal (radiator cap) 1
lValve and valve seat 2
Crack/damage ® Replace.
Exist fur deposits 3 ® Clean or
replace.

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THROTTLE CABLE ADJUSTMENT
THROTTLE CABLE ADJUSTMENT
1. Check:
lThrottle grip free play a
Out of specification ® Adjust.
Throttle grip free play a:
3 ~ 5 mm (0.12 ~ 0.20 in)
2. Adjust:
lThrottle grip free play
Throttle grip free play adjustment steps:
lRemove the throttle cable cap 1 and
throttle cable cover 2.
NOTE:
lBefore adjusting the throttle cable free
play, the engine idle speed should be
adjusted.
lWhen the motorcycle is accelerating,
throttle cable #1 3 is pulled and throttle
cable #2 4 is pushed.
1st step:
lLoosen the locknuts 5 on throttle cable
#2.
lAdjust the free play by changing their
tightening position.
2nd step:
lLoosen the locknuts 6 on throttle cable
#1.
lAdjust the free play by changing their
tightening position.
lTighten the locknuts.
WARNING
After adjusting, turn the handlebar to
right and left and make sure that the
engine idling does not run faster.
lInstall the throttle cable cover and throttle
cable cap.
T R..
Throttle cable cover:
4 Nm (0.4 m • kg, 2.9 ft • lb)
2
1

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ENGINE OIL REPLACEMENT
7. If the oil filter is to be replaced during this
oil change, remove the following parts
and reinstall them.
8. Install:
lCopper washer 1
lOil strainer (frame) 2
lOil hose 3
lBolt (oil hose) 4
lOil hose clamp 5
lLower engine bracket
9. Install:
lCopper washer
lOil filter element drain bolt
lCrankcase oil drain bolt
lFrame oil drain bolt
10. Fill:
lEngine oil
11. Check:
lOil leakage
12. Install:
lOil tank cap
13. Check:
lEngine oil level Replacement steps:
lRemove the oil filter element cover 1 and
oil filter element 2.
lCheck the O-rings 3, if cracked or dam-
aged, replace them with a new one.
lInstall the oil filter element and oil filter ele-
ment cover.
T R..
Oil filter element cover:
10 Nm (1.0 m • kg, 7.2 ft • lb)
Oil quantity:
Total amount:
1.7 L (1.50 Imp qt, 1.80 US qt)
Periodic oil change:
1.5 L (1.32 Imp qt, 1.59 US qt)
With oil filter replacement:
1.6 L (1.41 Imp qt, 1.69 US qt)
T R..90 Nm (9.0 m · kg, 65 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..2 Nm (0.2 m · kg, 1.4 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
T R..23 Nm (2.3 m · kg, 17 ft · lb)

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OIL PRESSURE INSPECTION
1. Check:
lOil pressure
Checking steps:
lSlightly loosen the oil pressure check bolt
1.
lStart 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.
lCheck oil passages and oil pump for dam-
age or leakage.
lStart the engine after solving the prob-
lem(s) and recheck the oil pressure.
lTighten the oil pressure check bolt.
T R..
Oil pressure check bolt:
10 Nm (1.0 m • kg, 7.2 ft • lb)
PILOT SCREW ADJUSTMENT
1. Adjust:
lPilot screw 1
Adjustment steps:
NOTE:
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 num-
ber as the factory-set number of turns out.
lTurn in the pilot screw until it is lightly
seated.
lTurn out the pilot screw by the factory-set
number of turns.
Pilot screw:
1-3/4 turns out (example)
OIL PRESSURE INSPECTION/
PILOT SCREW ADJUSTMENT

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ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it
up.
2. Attach:
lInductive tachometer
To spark plug lead.
3. Adjust:
lEngine idling speed
Adjustment steps:
lAdjust the pilot screw.
Refer to “PILOT SCREW ADJUSTMENT”
section.
lTurn the throttle stop screw 1 until the
engine runs at the lowest possible speed.
To increase idle speed ®
Turn the throttle stop screw 1 in a.
To decrease idle speed ®
Turn the throttle stop screw 1 out b.
Inductive tachometer:
YU-08036-B
Engine tachometer:
90890-03113
Engine idling speed:
1,700 ~ 1,900 r/min
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
NOTE:
lThe valve clearance should be adjusted
when the engine is cool to the touch.
lThe piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
lSeat
lFuel tank
Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section in the CHAP-
TER 4.
2. Drain:
lCoolant
Refer to “COOLANT REPLACEMENT”
section.
ENGINE IDLING SPEED ADJUSTMENT/
VALVE CLEARANCE INSPECTION AND ADJUSTMENT

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VALVE CLEARANCE INSPECTION AND ADJUSTMENT
3. Remove:
lRight radiator
Refer to “RADIATOR” section in the
CHAPTER 4.
lCarburetor
Refer to “CARBURETOR” section in
the CHAPTER 4.
lSpark plug
lUpper engine bracket
lCylinder head cover
Refer to “CAMSHAFTS” section in the
CHAPTER 4.
4. Remove:
lTiming mark accessing screw 1
lCrankshaft end accessing screw 2
lO-ring
5. Check:
lValve clearance
Out of specification ® Adjust.
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)

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DRIVE CHAIN SLACK ADJUSTMENT
5. Install:
lChain joint 1
lO-ring 2
lDrive chain 3
NOTE:
When installing the drive chain, apply the lith-
ium soap base grease on the chain joint and
O-rings.
6. Install:
lLink plate 4
NOTE:
lPress the link plate onto the chain joint using
a chain rivetter 5.
lRivet the end of the chain joint using a chain
rivetter 6.
lAfter rivetting the chain joint, make sure its
movement is smooth.
7. Lubricate:
lDrive chain
Drive chain lubricant:
SAE 10W-30 motor oil or suit-
able chain lubricants
EC36A060
DRIVE CHAIN SLACK ADJUSTMENT
1. Elevate the rear wheel by placing the
suitable stand under the engine.
2. Check:
lDrive chain slack a
Above the seal guard installation bolt.
Out of specification ® Adjust.
NOTE:
Before checking and/or adjusting, rotate the
rear wheel through several revolutions and
check the slack several times to find the tight-
est point. Check and/or adjust chain slack with
rear wheel in this “tight chain” position.
Drive chain slack:
40 ~ 50 mm (1.6 ~ 2.0 in)