clutch YAMAHA WR 250F 2017 Owner's Manual

PRE-OPERATION INSPECTION AND MAINTENANCE
3-9
EAS2GBB079
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EAS2GBB080GENERAL INSPECTION AND MAINTENANCE
TIP
Perform usual maintenance enough so that, in the race course, a confirmation of that and simple set-
ting adjustments may only be left, in order to get enough time to use effectively.ITEM inspect Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.3-10 – 12
FuelCheck that a fresh gasoline is filled in the fuel tank.
Check the fuel line for leakage.1-30
Engine oilCheck that the oil level is correct. Check the crank-
case and oil line for leakage.3-16 – 18
Gear shifter and clutchCheck that gears can be shifted correctly in order and
that the clutch operates smoothly.3-12 – 13
Throttle grip/HousingCheck that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and
housing, if necessary.3-13 – 14
BrakesCheck the play of front brake and effect of front and
rear brake.3-25 – 31
Drive chainCheck drive chain slack and alignment. Check that
the drive chain is lubricated properly.3-31
5-69 – 71
WheelsCheck for excessive wear and tire pressure. Check
for loose spokes and have no excessive play.3-36 – 37
SteeringCheck that the handlebar can be turned smoothly and
have no excessive play.3-37 – 38
Front forks and rear
shock absorberCheck that they operate smoothly and there is no oil
leakage.3-32 – 36
Cables (wires)Check that the clutch and throttle cables move
smoothly. Check that they are not caught when the
handlebars are turned or when the front forks travel
up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and
has no cracks.3-15 – 16
Rear wheel sprocketCheck that the rear wheel sprocket tightening bolt is
not loose.5-10 – 11
LubricationCheck for smooth operation. Lubricate if necessary. 3-14
3-38 – 39
Bolts and nutsCheck the chassis and engine for loose bolts and
nuts.1-34 – 35
Lead connectorsCheck that the AC magneto, ECU and ignition coil are
connected tightly.1-9 – 12
SettingsIs the machine set suitably for the condition of the rac-
ing course and weather or by taking into account the
results of test runs before racing? Are inspection and
maintenance completely done?4-1 – 8

ENGINE
3-12
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EAS2GBB087CHECKING THE COOLANT CIRCULATORY
SYSTEM FOR LEAKS
1. Check:
• Coolant level
2. Install:
• Radiator cap tester “1”
• Adapter “2”
3. Activate the tester to apply the test pressure.
ECA
NOTICE
• Do not apply such a high pressure as ex-
ceeds the test pressure.
• Make sure that a checkup after the cylin-
der head gasket is replaced is made after 3
minutes of warm-up.
• Make sure that coolant is filled up to the
upper level beforehand.4. Check:
• Pressure value
No stay for 5 to 10 seconds at the test pres-
sure value  Correct.
• Radiator
• Radiator hose connections
Coolant leaks  Correct or replace.
• Radiator hoses
Bulges  Replace
EWA
WARNING
When the radiator cap tester is removed,
coolant will spout; therefore, cover it with a
cloth beforehand.
EAS2GBB088ADJUSTING THE CLUTCH LEVER FREE
PLAY
1. Check:
• Clutch lever free play “a”
Out of specification  Regulate.
2. Adjust:
• Clutch lever free play
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Handlebar side
a. Turn the adjuster “1” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained. Radiator cap tester
90890-01325
Mityvac cooling system tester kit
YU-24460-A
Radiator cap tester adapter
90890-01352
Pressure tester adapter
YU-33984
Test pressure value
196 kPa (1.96 kg/cm
2, 27.9 psi)
Clutch lever free play
7.0–12.0 mm (0.28–0.47 in)
Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.

ENGINE
3-13
TIP
If the clutch lever free play cannot be obtained
on the handlebar side, use the adjuster on the
clutch cable side.
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Clutch cable side
a. Slide the clutch cable cover.
b. Loosen the locknut “1”.
c. Turn the adjuster “2” in direction “a” or “b”
until the specified clutch lever free play is ob-
tained.
d. Tighten the locknut “1”.
e. Return the clutch cable cover to its original
position.
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EAS2GBB089ADJUSTING THE THROTTLE GRIP FREE
PLAY
TIP
Prior to adjusting throttle grip free play, the en-
gine idling speed should be adjusted.
1. Check:
• Throttle grip free play “a”
Out of specification  Regulate.
2. Adjust:
• Throttle grip free play
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a. Loosen the locknut “1”.
b. Turn the adjuster “2” until the specified free
play is obtained.
c. Tighten the locknut.
EWA
WARNING
After adjusting the throttle grip free play,
turn the handlebar to the right and to the left
to ensure that this does not cause the en-
gine idling speed to change.
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Direction “a”
Clutch lever free play is increased.
Direction “b”
Clutch lever free play is decreased.
Locknut
4.0 Nm (0.40 m·kgf, 2.9 ft·lbf)
a b
1
T R..
1
2a
b
Throttle grip free play
3.0–6.0 mm (0.12–0.24 in)
Direction “a”
Throttle grip free play is increased.
Direction “b”
Throttle grip free play is decreased.
1 2
b
a

ENGINE
3-17
ECA
NOTICE
• Since engine oil also lubricates the clutch,
the wrong oil types or additives could
cause clutch slippage. Therefore, do not
add any chemical additives.
• Do not allow foreign material to enter the
crankcase.
EAS2GBB097CHANGING THE ENGINE OIL
Stand the vehicle upright on a level surface.
1. Start the engine, warm this up for 3 minutes,
and then stop the engine and wait about 5
minutes.
2. Place an oil pan under the drain bolt.
3. Remove:
• Engine guard “1”
• Oil filler cap “2”
• Drain bolt (with gasket) “3”4. If the oil filter element is also to be replaced,
perform the following procedure.
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a. Remove the oil filter element cover “1” and
oil filter element “2”.
b. Replace the O-ring “3”.
c. Install the new oil filter element and the oil fil-
ter element cover.
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5. To check the oil strainer, perform the follow-
ing procedure.
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a. Remove the oil strainer “1”.
b. Check the oil strainer.
Damage  Replace.
Clogging due to dirt  Wash with kerosene.
c. Replace the O-ring “2”. Recommended brand
YAMALUBE
Type
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
12
Oil filter element cover bolt
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
3
1
3
2
New
T R..
1
2New

CHASSIS
3-38
c. Turn the front fork to the right and left a few
times, and make sure that the steering ro-
tates smoothly. If it does not turn smoothly,
remove the lower bracket and check the up-
per and lower bearings.
Refer to “STEERING HEAD” on page 5-53.
d. Loosen the ring nut fully turn and then tight-
en it to specification with a steering nut
wrench.
EWA
WARNING
Do not overtighten the lower ring nut.
e. Check the steering head for looseness or
binding by turning the front fork all the way in
both directions. If any binding is felt, remove
the lower bracket and check the upper and
lower bearings.
Refer to “STEERING HEAD” on page 5-53.
f. Install the washer “1”.
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5. Install:
• Upper bracket
Refer to “STEERING HEAD” on page 5-53.
• Handlebar
Refer to “HANDLEBAR” on page 5-33.
EAS2GBB124CHECKING AND LUBRICATING THE CA-
BLES
The following procedure applies to all of the in-
ner and outer cables.
EWA
WARNING
Damaged outer cable may cause the cable
to corrode and interfere with its movement.
Replace damaged outer cable and inner ca-
bles as soon as possible.1. Check:
• Outer cable
Damage  Replace.
2. Check:
• Cable operation
Rough movement  Lubricate.
TIP
Hold the cable end upright and pour a few
drops of lubricant into the cable sheath or use
a suitable lubricating device.
EAS2GBB125LUBRICATING THE LEVERS
1. Lubricate the pivoting points and metal-to-
metal moving parts of the following parts.
•Brake lever
• Clutch lever
EAS2GBB126LUBRICATING THE PEDAL
1. Lubricate the pivoting point and metal-to-
metal moving parts of the pedal.
EAS2GBB127LUBRICATING THE DRIVE CHAIN
The drive chain consists of many interacting
parts. If the drive chain is not maintained prop-
erly, it will wear out quickly. Therefore, the drive
chain should be serviced, especially when the
vehicle is used in dusty areas.
This vehicle has a drive chain with small rubber
O-rings between each side plate. Steam clean-
ing, high-pressure washing, certain solvents,
and the use of a coarse brush can damage
these O-rings. Therefore, use only kerosene to
clean the drive chain. Wipe the drive chain dry
and thoroughly lubricate it with engine oil or
chain lubricant that is suitable for O-ring chains.
Do not use any other lubricants on the drive
chain since they may contain solvents that
could damage the O-rings. Ring nut (initial tightening torque)
38 Nm (3.8 m·kgf, 27 ft·lbf)
Ring nut (final tightening torque)
7 Nm (0.7 m·kgf, 5.1 ft·lbf)
T R..
T R..
1
Recommended lubricant
Engine oil or a suitable cable lu-
bricant
Recommended lubricant
Silicone grease
Recommended lubricant
Lithium-soap-based grease
Recommended lubricant
Lithium-soap-based grease

HANDLEBAR
5-33
EAS2GBB193
HANDLEBAR
Removing the handlebar
Order Part name Q’ty Remarks
1 Clutch cable 1 Disconnect.
2 Clutch switch 1
3 Clutch lever holder 1
4 Engine stop switch 1
5 Brake master cylinder 1
6 Throttle cable cap 1
7 Throttle cable (pull) 1 Disconnect.
8 Throttle cable (return) 1 Disconnect.
9 Right grip 1
10 Tube guide 1
11 Start switch 1
12 Left grip 1
13 Upper handlebar holder 2
14 Handlebar 1

HANDLEBAR
5-35
EAS2GBB194REMOVING THE HANDLEBAR
1. Stand the vehicle on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Remove:
•Clutch switch “1”
TIP
Press the projection, and remove it from the
clutch lever assembly.
3. Remove:
• Handlebar grip “1”
TIP
Blow compressed air between the left handle-
bar and the handlebar grip, and gradually push
the grip off the handlebar.
4. Remove:
• Throttle cable housings “1”
• Throttle grip “2”
TIP
While removing the throttle cable housing, pull
back the rubber cover “3”.
EAS2GBB195CHECKING 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.
EAS2GBB196INSTALLING THE HANDLEBAR
1. Stand the vehicle upright on a level surface.
EWA
WARNING
Securely support the vehicle so that there is
no danger of it falling over.
2. Install:
• Damper “1”
• Lower handlebar holders“2” (temporarily)
• Handlebar “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.
ECA
Upper handlebar holder bolt
28 Nm (2.8 m·kgf, 20 ft·lbf)
T R..

HANDLEBAR
5-37
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5. Install:
• Engine stop switch “1”
• Clutch lever “2”
• Clutch lever holder “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.
6. Install:
• Right grip “1”
• Collar “2”
Apply adhesive to the tube guide “3”.
TIP
• Before applying the adhesive, wipe off grease
or oil on the tube guide surface “a” with a lac-
quer 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.7. Install:
• Rubber cover “1”
• Throttle grip “2”
TIP
Apply the lithium-soap-based grease on the
throttle grip sliding surface.
8. Install:
• Throttle cables “1”
TIP
Slightly coat the end of throttle cable and inside
of throttle grip with lithium-soap-based grease.
Then, mount the throttle grip onto the handle-
bar. Engine stop switch screw
0.5 Nm (0.05 m·kgf, 0.36 ft·lbf)
Clutch lever holder bolt
3.8 Nm (0.38 m·kgf, 2.8 ft·lbf)
T R..
64
1b
c
3 64

HANDLEBAR
5-39
12.Install:
• Clutch cable “1”
TIP
Before installation, apply the lithium-soap-
based grease to the clutch cable end.
13.Adjust:
• Clutch lever free play
Refer to “ADJUSTING THE CLUTCH LE-
VER FREE PLAY” on page 3-12.
14.Adjust:
• Throttle grip free play
Refer to “ADJUSTING THE THROTTLE
GRIP FREE PLAY” on page 3-13.Clutch lever free play
7.0–12.0 mm (0.28–0.47 in)
Throttle grip free play
3.0–6.0 mm (0.12–0.24 in)
1LS

CLUTCH......................................................................................................... 6-42
REMOVING THE CLUTCH ...................................................................... 6-45
CHECKING THE FRICTION PLATES...................................................... 6-45
CHECKING THE CLUTCH PLATES ........................................................ 6-45
CHECKING THE CLUTCH SPRINGS...................................................... 6-45
CHECKING THE CLUTCH HOUSING ..................................................... 6-46
CHECKING THE CLUTCH BOSS ............................................................ 6-46
CHECKING THE PRESSURE PLATE ..................................................... 6-46
CHECKING THE PUSH LEVER SHAFT .................................................. 6-46
CHECKING THE CLUTCH PUSH RODS ................................................ 6-46
CHECKING THE PRIMARY DRIVE GEAR .............................................. 6-46
CHECKING THE PRIMARY DRIVEN GEAR ........................................... 6-47
INSTALLING THE OIL SEAL................................................................... 6-47
INSTALLING THE RIGHT CRANKCASE COVER ................................... 6-47
INSTALLING THE CLUTCH ..................................................................... 6-47
INSTALLING THE KICKSTARTER LEVER ............................................. 6-50
KICKSTATER................................................................................................. 6-51
REMOVING THE KICK SHAFT ASSEMBLY ........................................... 6-52
CHECKING THE KICK SHAFT AND RATCHET WHEEL ........................ 6-52
CHECKING THE KICK GEAR, KICK IDLE GEAR AND RATCHET
WHEEL .................................................................................................... 6-52
INSTALLING THE KICK SHAFT ASSEMBLY .......................................... 6-52
INSTALLING THE KICK IDLE GEAR ....................................................... 6-53
SHIFT SHAFT................................................................................................. 6-54
REMOVING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ......... 6-56
REMOVING THE SEGMENT ................................................................... 6-56
CHECKING THE SHIFT SHAFT .............................................................. 6-56
CHECKING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ......... 6-56
CHECKING THE STOPPER LEVER ....................................................... 6-56
INSTALLING THE STOPPER LEVER ..................................................... 6-56
INSTALLING THE SEGMENT.................................................................. 6-57
INSTALLING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ....... 6-57
INSTALLING THE SHIFT SHAFT ............................................................ 6-58
INSTALLING THE SHIFT PEDAL ............................................................ 6-58
OIL PUMP AND BALANCER GEAR............................................................. 6-59
REMOVING THE BALANCER ................................................................. 6-62
CHECKING THE PRIMARY DRIVE GEAR, BALANCER DRIVE GEAR,
AND BALANCER WEIGHT GEAR .......................................................... 6-62
CHECKING THE BALANCER .................................................................. 6-62
CHECKING THE OIL PUMP .................................................................... 6-62
ASSEMBLING THE OIL PUMP ................................................................ 6-63
INSTALLING THE OIL PUMP AND BALANCER GEAR .......................... 6-63