checking oil YAMAHA WR 250F 2016 User Guide

FRONT BRAKE
5-22
TIP
Turn the handlebar toward right and left to
make sure that the brake hose does not touch
other parts (e.g., wire harness, cables, leads).
Adjust if necessary.
3. Pour brake fluid to the brake master cylinder
reservoir up to the specified level.
EWA
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When refilling, be careful that water does
not enter the brake master cylinder reser-
voir. Water will significantly lower the boil-
ing point of the brake fluid and could
cause vapor lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
4. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
5. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-29.6. Check:
• Brake lever free play
Refer to “ADJUSTING THE FRONT
BRAKE” on page 3-25.
• Brake lever operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
Specified brake fluid
DOT 4
a

REAR BRAKE
5-30
EWA
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When refilling, be careful that water does
not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
5. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
6. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-29.
7. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
EAS2GB7189REMOVING THE REAR BRAKE MASTER
CYLINDER
TIP
Before removing the rear brake master cylin-
der, drain the brake fluid from the entire brake
system.1. Remove:
• Union bolt
• Copper washers
• Brake hose
TIP
To drain any remaining brake fluid, place a con-
tainer under the master cylinder and the end of
the brake hose.
EAS2GB7190CHECKING THE REAR BRAKE MASTER
CYLINDER
1. Check:
• Brake master cylinder “1”
Damage/scratches/wear  Replace.
• Brake fluid delivery passages “2”
(brake master cylinder body)
Obstruction  Blow out with compressed
air.
2. Check:
• Brake master cylinder kit
Damage/wear  Replace.
3. Check:
• Master cylinder reservoir cap
Crack/damage  Replace.
• Brake master cylinder reservoir diaphragm
holder
• Brake master cylinder reservoir diaphragm
Crack/damage  Replace.
4. Check:
• Brake hoses
Cracks/damage/wear  Replace.
EAS2GB7191ASSEMBLING THE REAR BRAKE MASTER
CYLINDER
EWA
WARNING
• Before installation, all internal brake com-
ponents should be cleaned and lubricated
with clean or new brake fluid.
• Never use solvents on internal brake com-
ponents.
a
1
2

REAR BRAKE
5-32
2. Pour brake fluid to the brake fluid reservoir
up to the specified level.
EWA
WARNING
• Use only the designated brake fluid. Other
brake fluids may cause the rubber seals to
deteriorate, causing leakage and poor
brake performance.
• Refill with the same type of brake fluid that
is already in the system. Mixing brake flu-
ids may result in a harmful chemical reac-
tion, leading to poor brake performance.
• When refilling, be careful that water does
not enter the brake fluid reservoir. Water
will significantly lower the boiling point of
the brake fluid and could cause vapor
lock.
ECA
NOTICE
Brake fluid may damage painted surfaces
and plastic parts. Therefore, always clean
up any spilt brake fluid immediately.
3. Bleed:
• Brake system
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24.
4. Check:
• Brake fluid level
The minimum level mark “a” or below 
Add.
Refer to “CHECKING THE BRAKE FLUID
LEVEL” on page 3-29.5. Check:
• Brake pedal operation
A softy or spongy feeling  Bleed the brake
system.
Refer to “BLEEDING THE BRAKE SYS-
TEM” on page 3-24. Specified brake fluid
DOT 4
a
a

FRONT FORK
5-43
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5. Remove:
• Base valve “1”
(from the damper assembly)
TIP
Hold the damper assembly with the cap bolt
ring wrench “2” and use the cap bolt wrench “3”
to remove the base valve.
EAS2GB7200CHECKING THE FRONT FORK LEGS
1. Check:
• Inner tube surface “a”
Scratches  Repair or replace.
Use #1000 grit wet sandpaper.
Damaged oil lock piece  Replace.
• Inner tube bends
Out of specification  Replace.
Use the dial gauge “1”.
TIP
The bending value is shown by one half of the
dial gauge reading.
EWA
WARNING
Do not attempt to straighten a bent inner
tube as this may dangerously weaken it.
2. Check:
• Outer tube
Scratches/wear/damage  Replace.
3. Measure:
• Fork spring free length “a”
Out of specification  Replace.
4. Check:
• Damper assembly “1”
Bend/damage  Replace.
• O-ring “2”
Wear/damage  Replace.
ECA
NOTICE
• The front fork leg has a built-in damper ad-
justing rod and a very sophisticated inter-
nal construction, which are particularly
sensitive to foreign material.
• When disassembling and assembling the
front fork leg, do not allow any foreign ma-
terial to enter the front fork. Cap bolt wrench
90890-01500
Cap bolt wrench
YM-01500
Cap bolt ring wrench
90890-01501
Cap bolt ring wrench
YM-01501
Inner tube bending limit
0.2 mm (0.01 in)
1 23
Fork spring free length
470.0 mm (18.50 in)
Limit
465.0 mm (18.31 in)

REAR SHOCK ABSORBER ASSEMBLY
5-62
2. Remove:
• Upper bearing “1”
TIP
Remove the bearing by pressing its outer race.
3. Remove:
• Lower bearing “1”
TIP
Remove the bearing by pressing its outer race.
EAS2GB7212CHECKING THE REAR SHOCK ABSORBER
ASSEMBLY
1. Check:
• Rear shock absorber rod
Bends/damage  Replace the rear shock
absorber assembly.
• Rear shock absorber
Gas leaks/oil leaks  Replace the rear
shock absorber assembly.•Spring
Damage/wear  Replace.
• Spring guide
Damage/wear  Replace.
• Bearing
Damage/wear  Replace.
•Bolts
Bends/damage/wear  Replace.
EAS2GB7213CHECKING THE CONNECTING ARM AND
RELAY ARM
1. Check:
• Connecting arm
• Relay arm
Damage/wear  Replace.
2. Check:
• Bearing
• Spacers
Damage/pitting/scratches  Replace the
bearings and spacers as a set.
3. Check:
• Oil seals
Damage/pitting  Replace.
EAS2GB7214INSTALLING THE RELAY ARM
1. Lubricate:
• Oil seals
• Bearing
• Spacers
• Washers
•Collars
2. Install:
• Bearing “1”
• Washer “2”
• Oil seals “3”
(to relay arm “4”)
1
Recommended lubricant
Molybdenum disulfide grease
Installed depth “a”
0 mm (0 in)
New
3 3
43
2 2
22
a
1
11

SWINGARM
5-66
EAS2GB7217REMOVING 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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EAS2GB7218REMOVING THE BEARING
1. Remove:
• Bearing “1”
TIP
Remove the bearing by pressing its outer race.
EAS2GB7219CHECKING 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..

CLUTCH......................................................................................................... 6-40
REMOVING THE CLUTCH ...................................................................... 6-43
CHECKING THE FRICTION PLATES...................................................... 6-43
CHECKING THE CLUTCH PLATES ........................................................ 6-43
CHECKING THE CLUTCH SPRINGS...................................................... 6-43
CHECKING THE CLUTCH HOUSING ..................................................... 6-44
CHECKING THE CLUTCH BOSS ............................................................ 6-44
CHECKING THE PRESSURE PLATE ..................................................... 6-44
CHECKING THE PUSH LEVER SHAFT .................................................. 6-44
CHECKING THE CLUTCH PUSH RODS ................................................ 6-44
CHECKING THE PRIMARY DRIVE GEAR .............................................. 6-44
CHECKING THE PRIMARY DRIVEN GEAR ........................................... 6-45
INSTALLING THE OIL SEAL................................................................... 6-45
INSTALLING THE RIGHT CRANKCASE COVER ................................... 6-45
INSTALLING THE CLUTCH ..................................................................... 6-45
INSTALLING THE KICKSTARTER LEVER ............................................. 6-48
KICKSTATER................................................................................................. 6-49
REMOVING THE KICK SHAFT ASSEMBLY ........................................... 6-50
CHECKING THE KICK SHAFT AND RATCHET WHEEL ........................ 6-50
CHECKING THE KICK GEAR, KICK IDLE GEAR AND RATCHET
WHEEL .................................................................................................... 6-50
INSTALLING THE KICK SHAFT ASSEMBLY .......................................... 6-50
INSTALLING THE KICK IDLE GEAR ....................................................... 6-51
SHIFT SHAFT................................................................................................. 6-52
REMOVING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ......... 6-53
REMOVING THE SEGMENT ................................................................... 6-53
CHECKING THE SHIFT SHAFT .............................................................. 6-53
CHECKING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ......... 6-53
CHECKING THE STOPPER LEVER ....................................................... 6-53
INSTALLING THE STOPPER LEVER ..................................................... 6-54
INSTALLING THE SEGMENT.................................................................. 6-54
INSTALLING THE SHIFT GUIDE AND SHIFT LEVER ASSEMBLY ....... 6-54
INSTALLING THE SHIFT SHAFT ............................................................ 6-55
INSTALLING THE SHIFT PEDAL ............................................................ 6-55
OIL PUMP AND BALANCER GEAR............................................................. 6-56
REMOVING THE BALANCER ................................................................. 6-58
CHECKING THE PRIMARY DRIVE GEAR, BALANCER SHAFT DRIVE
GEAR, AND BALANCER WEIGHT GEAR .............................................. 6-58
CHECKING THE BALANCER .................................................................. 6-58
CHECKING THE OIL PUMP .................................................................... 6-58
ASSEMBLING THE OIL PUMP ................................................................ 6-59
INSTALLING THE OIL PUMP AND BALANCER GEAR .......................... 6-60

GENERATOR AND STARTER CLUTCH....................................................... 6-62
REMOVING THE GENERATOR .............................................................. 6-64
CHECKING THE STARTER CLUTCH ..................................................... 6-64
INSTALLING THE STARTER CLUTCH ................................................... 6-65
INSTALLING THE GENERATOR............................................................. 6-65
CRANKCASE................................................................................................. 6-68
DISASSEMBLING THE CRANKCASE..................................................... 6-71
REMOVING THE CRANKCASE BEARING ............................................. 6-71
CHECKING THE TIMING CHAIN, TIMING CHAIN GUIDE,
OIL STRAINER ........................................................................................ 6-71
CHECKING THE CRANKCASE ............................................................... 6-71
INSTALLING THE OIL SEAL................................................................... 6-72
ASSEMBLING THE CRANKCASE........................................................... 6-72
CRANKSHAFT ASSEMBLY AND BALANCER SHAFT............................... 6-73
REMOVING THE CRANKSHAFT ASSEMBLY ........................................ 6-74
CHECKING THE CRANKSHAFT ASSEMBLY......................................... 6-74
INSTALLING THE CRANKSHAFT ASSEMBLY....................................... 6-75
INSTALLING THE BALANCER SHAFT ................................................... 6-75
TRANSMISSION............................................................................................. 6-76
REMOVING THE TRANSMISSION ......................................................... 6-77
CHECKING THE SHIFT FORKS.............................................................. 6-77
CHECKING THE SHIFT DRUM ASSEMBLY ........................................... 6-78
CHECKING THE TRANSMISSION .......................................................... 6-78
INSTALLING THE TRANSMISSION ........................................................ 6-78

CAMSHAFT
6-16
EAS2GB7242CHECKING THE DECOMPRESSION SYS-
TEM
1. Check:
• Decompression system
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a. Check that the decompressor cam “1”
moves smoothly.
b. Check that the decompressor lever pin “2”
projects from the camshaft.
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EAS2GB7243INSTALLING THE CAMSHAFTS
1. Install:
• Exhaust camshaft “1”
• Intake camshaft “2”
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a. Turn the crankshaft counterclockwise with a
wrench.
TIP
• Apply molybdenum disulfide oil to the cam-
shafts.
• Apply the engine oil on the decompression
system.
b. Align the top dead center (TDC) mark “a” on
the rotor with the alignment mark “b” on the
crankcase cover.c. Fit the timing chain “3” onto both camshaft
sprockets and install the camshafts on the
cylinder head.
TIP
Make sure that the alignment mark “c” on the
exhaust camshaft sprocket and the alignment
mark “d” on the intake camshaft sprocket are
aligned with the edge of the cylinder head.
ECA
NOTICE
Do not turn the crankshaft during the cam-
shaft installation. Damage or improper
valve timing will result.
d. Install the clips, the camshaft caps and the
bolts (camshaft cap).
TIP
• Before installing the clips, cover the cylinder
head with a clean cloth to prevent the clips
from coming off into the cylinder head cavity.
• Apply the engine oil to the threads and con-
tact surfaces.
• Tighten the bolts to the specified torque in two
or three steps in the proper tightening se-
quence as shown.
ECA
NOTICE
The bolts (camshaft cap) must be tightened
evenly, or damage to the cylinder head,
camshaft caps, and camshaft will result.
1
2
Bolt (camshaft cap)
10 Nm (1.0 m·kgf, 7.2 ft·lbf)
ab
dc
3
T R..

VALVES AND VALVE SPRINGS
6-26
EAS2GB7252CHECKING THE VALVE SEATS
1. Eliminate:
• Carbon deposits
(from the valve face and valve seat)
2. Check:
• Valve seat
Pitting/wear  Replace the cylinder head.
3. Measure:
• Valve seat contact width “a”
Out of specification  Replace the cylinder
head.
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a. Apply Mechanic’s blueing dye (Dykem) “b”
onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide and
onto the valve seat to make a clear impres-
sion.
d. Measure the valve seat contact width “c”.
TIP
Where the valve seat and the valve face are in
contact with each other, the blueing will have
been removed.
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4. Lap:
• Valve face
• Valve seat
ECA
NOTICE
This model uses titanium intake and ex-
haust valves.
Do not use the valves used for lapping the
valve seat. Always replace the valves used
for lapping with new ones.
TIP
• When replacing the cylinder head, replace
also the valves with new ones without them.
• When replacing the valves or the valve
guides, use new valves to lap the valve seats,
and then replace them with new valves.
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a. Apply a coarse lapping compound “a” to the
valve face.
ECA
NOTICE
Do not let the lapping compound enter the
gap between the valve stem and the valve
guide.
b. Apply molybdenum disulfide oil onto the
valve stem.
c. Install the valve into the cylinder head.
d. Turn the valve until the valve face and the
valve seat are evenly polished, then clean
off all of the lapping compound. Valve seat contact width (intake)
0.90–1.10 mm (0.0354–0.0433 in)
Valve seat contact width (ex-
haust)
0.90–1.10 mm (0.0354–0.0433 in)
c