lock YAMAHA WR 250F 2015 Owner's Manual

CHASSIS
3-26
EAS2GB2107ADJUSTING THE REAR BRAKE
1. Check:
• Brake pedal position “a”
(distance from the top of the rider footrest to
the top of the brake pedal)
Out of specification  Regulate.
2. Adjust:
• Brake pedal position
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a. Loosen the locknut “1”.
b. Turn the adjusting bolt “2” in direction “a” or
“b” until the specified brake pedal position is
obtained.
c. Tighten the locknut.
EWA
WARNING
A soft or spongy feeling in the brake pedal
can indicate the presence of air in the brake
system. Before running, bleed the brake
system. Air in the brake system will cause
braking performance to be reduced.
ECA
NOTICE
After adjusting the brake pedal position,
make sure that there is no brake drag.
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EAS2GB2108CHECKING THE FRONT BRAKE PADS
1. Measure:
• Brake pad thickness “a”
Out of specification  Replace as a set.
TIP
The pads worn up to the indicator “b” grooves
mean that the brake pad thickness limit is
reached.
2. Replace:
• Brake pads
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a. Remove the pad pin plug “1”.
b. Loosen the pad pin “2”.
c. Remove the brake caliper “3” from the front
fork. Brake pedal position
5 mm (0.20 in)
Direction “a”
Brake pedal is raised.
Direction “b”
Brake pedal is lowered.
Locknut
6 Nm (0.6 m·kgf, 4.3 ft·lbf)1 2
a
b
T R..
Brake pad lining thickness (inner)
4.4 mm (0.17 in)
Limit
1.0 mm (0.04 in)
Brake pad lining thickness (outer)
4.4 mm (0.17 in)
Limit
1.0 mm (0.04 in)
a
b
a
1

CHASSIS
3-30
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.
EAS2GB2112ADJUSTING THE DRIVE CHAIN SLACKECA
NOTICE
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the speci-
fied limits.
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. Shift the transmission into the neutral posi-
tion.
3. Pull the drive chain up above the drive chain
guide installation bolt with a force of about
50 N (5.0 kgf, 36 lbf).
4. Check:
• Drive chain slack “a”
Out of specification  Regulate.
TIP
Measure drive chain slack between the drive
chain guide and the bottom of the chain as
shown.5. Adjust:
• Drive chain slack
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a. Loosen the wheel axle nut “1”.
b. Loosen both locknuts “2”.
c. Turn the adjusting bolt “3” in direction “a” or
“b” until the specified drive chain slack is ob-
tained.
TIP
• To maintain the proper wheel alignment, ad-
just both sides evenly.
• Push the rear wheel forward to make sure that
there is no clearance between the swingarm
end plates and the ends of the swingarm.
d. Tighten the locknut.
e. Tighten the wheel axle nut.
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Drive chain slack
50–60 mm (1.97–2.36 in)
Direction “a”
The drive chain slack decreases.
Direction “b”
The drive chain slack increases.
Locknut
21 Nm (2.1 m·kgf, 15 ft·lbf)
Wheel axle nut
125 Nm (12.5 m·kgf, 90 ft·lbf)
a
1
32
a
b
T R..
T R..

CHASSIS
3-33
EAS2GB2118CHECKING THE SWINGARM OPERATION
1. Check:
• Swingarm smooth action
• Swingarm free play
Refer to “SWINGARM” on page 5-64.
EAS2GB2119CHECKING THE REAR SUSPENSION
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. Check:
• Rear shock absorber assembly
Gas leaks/oil leaks  Replace the rear
shock absorber assembly.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-57.
3. Check:
• Rear shock absorber assembly smooth ac-
tion
• Rear suspension link smooth action
Sit astride the seat and shake your body up
and down several times to check whether
the rear shock absorber assembly operates
smoothly.
Unsmooth operation  Correct or replace.
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-57.
EAS2GB2120ADJUSTING THE REAR SHOCK ABSORB-
ER ASSEMBLY
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.Spring preload
ECA
NOTICE
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Remove:
• Rear frame
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-57.
2. Adjust:
• Spring preload
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a. Loosen the locknut “1”.
b. Loosen the adjuster “2” until there is some
clearance between the spring and the ad-
juster.
c. Measure the spring free length “a”.
d. Turn the adjuster in the direction of “b” or “c”
to make an adjustment.
Direction “b”
Spring preload is increased (suspen-
sion is harder).
Direction “c”
Spring preload is decreased (suspen-
sion is softer).
Spring installed length “d”
Minimum
Position in which the spring is
turned in 1.5 mm (0.06 in) from
its free length.
STD
Position in which the spring is
turned in 10 mm (0.39 in) from its
free length.
Maximum
Position in which the spring is
turned in 18 mm (0.71 in) from its
free length.

CHASSIS
3-34
TIP
• Be sure to remove all dirt and mud from
around the locknut and adjusting ring before
adjustment.
• The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjusting ring.
e. Tighten the locknut.
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3. Install:
• Rear frame
Refer to “REAR SHOCK ABSORBER AS-
SEMBLY” on page 5-57.
Rebound damping force
ECA
NOTICE
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Adjust:
• Rebound damping force
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a. Turn the adjuster “1” in the direction of “a” or
“b” to make an adjustment.
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High compression dampingECA
NOTICE
Do not turn the adjuster forcibly beyond its
adjusting range.
1. Adjust:
• High compression damping
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a. Turn the adjuster “1” in the direction of “a” or
“b” to make an adjustment. Locknut
30 Nm (3.0 m·kgf, 22 ft·lbf)
Direction “a”
Rebound damping force is increased
(suspension is harder).
Direction “b”
Rebound damping force is decreased
(suspension is softer).
c
b
d
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Rebound damping force
Maximum
Turn it in finger-tight.
STD
Turn it out by 14 clicks.*
Minimum
Turn it out by 30 clicks.*
* With the adjuster fully turned
Direction “a”
High compression damping force is in-
creased (suspension is harder).
Direction “b”
High compression damping force is de-
creased (suspension is softer).
High compression damping
Maximum
Turn it in finger-tight.
STD
Turn it out by 1 1/4 turns.*
Minimum
Turn it out by two turns.*
* With the adjuster fully turned
a
b
1

ELECTRICAL SYSTEM
3-39
EAS2GB2132
ELECTRICAL SYSTEM
EAS2GB2133CHECKING THE SPARK PLUG
1. Remove:
• Seat
• Air scoop (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
• Fuel tank “1”
Refer to “FUEL TANK” on page 8-1.
ECA
NOTICE
Do not use too much force to pull the hose.
TIP
Remove the fuel tank, turn this 180 ° clockwise,
and put it in the frame “2” as shown.
2. Remove:
• Spark plug cap
• Spark plug
Refer to “CAMSHAFT” on page 6-11.
ECA
NOTICE
In order not to allow the dirt accumulated
around the spark plug to drop from the
spark plug hole into the cylinder, clean it be-
fore removing the spark plug.
3. Check:
• Spark plug type
Wrong type  Replace.
4. Check:
• Electrode
Damage/wear  Replace the spark plug.
• Insulator
Abnormal color  Replace the spark plug.
Normal color is medium-to-light tan.5. Clean:
• Spark plug
(with a spark plug cleaner or a wire brush)
6. Measure:
• Spark plug gap “a”
Out of specification  Adjust the spark plug
gap.
7. Install:
• Spark plug
TIP
Before installing the spark plug, clean the spark
plug and gasket surface.
8. Install:
• Spark plug cap
• Fuel tank
• Air scoop (left/right)
• Seat
• Side cover (left/right)
Refer to “GENERAL CHASSIS” on page 5-
1.
EAS2GB2134CHECKING THE IGNITION TIMING
1. Remove:
• Timing mark accessing screw “1”
Manufacturer/model
NGK/LMAR8G
1
1
2
Spark plug gap
0.7–0.8 mm (0.028–0.031 in)
Spark plug
13 Nm (1.3 m·kgf, 9.4 ft·lbf)
T R..
1

CHASSIS
4-3
TIP
Generally a stiff spring gives a stiff riding feel-
ing. Rebound damping tends to become weak-
er, resulting in lack of a sense of contact with
the road surface or in a vibrating handlebar.
EAS2GB2145FRONT FORK SETTING PARTS
• Front fork spring “1”
TIP
The I.D. mark (slits) “a” is proved on the end of
the spring.
EAS2GB2146
REAR SUSPENSION SETTING
The rear shock absorber setting should be
made depending on the rider’s feeling of an ac-
tual run and the circuit conditions.
The rear suspension setting includes the fol-
lowing two factors:
1. Setting of spring preload
• Change the set length of the spring.
• Change the spring.
2. Setting of damping force
• Change the rebound damping force.
• Change the compression damping force.
EAS2GB2147CHOOSING SET LENGTH
1. Place a stand or a block under the engine to
put the rear wheel above the floor, and mea-
sure the length “a” between the rear wheel
axle center and the rear fender holding bolt.
2. Remove the stand or block from the engine
and, with a rider astride the seat, measure
the sunken length “b” between the rear
wheel axle center and the rear fender hold-
ing bolt.
3. Loosen the locknut “1” and make adjustment
by turning the adjuster “2” to achieve the
standard figure from the subtraction of the
length “b” from the length “a”. TypeSpring
rate N/
mmPart numberI.D.
Mark
(slits)
SOFT4.1 2GB-23141-A0 |||
4.2 2GB-23141-B0 ||||
4.3 2GB-23141-C0 |||||
STD 4.42GB-23141-30 —
2GB-23141-D0 |-|
STIFF4.5 2GB-23141-E0 |-||
4.6 33D-23141-30 |-|||
a
1
Standard figure
90–100 mm (3.5–3.9 in)

CHASSIS
4-6
EAS2GB2150SUSPENSION SETTING (FRONT FORK)
TIP
• If any of the following symptoms is experienced with the standard position as the base, make reset-
ting by reference to the adjustment procedure given in the same chart.
• Before any change, set the rear shock absorber sunken length to the standard figure 90–100 mm
(3.5–3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap
Stiff over entire
rangeCompression
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Oil amount Decrease oil amount by about
5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
Spring Replace with soft spring.
Unsmooth
movement over
entire rangeOuter tube
Inner tubeCheck for any bends, dents,
other noticeable scars, etc. If
any, replace affected parts.
Slide metal Replace with a new one for ex-
tended use.
Piston metal Replace with a new one for ex-
tended use.
Lower bracket
tightening
torqueRetighten to specified torque.
Poor initial
movementRebound
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Oil seals Apply grease in oil seal wall.
Soft over entire
range, bottom-
ing outCompression
damping forceTurn adjuster clockwise (about
2 clicks) to increase damping.
Oil amount Increase oil amount by about
5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
Spring Replace with stiff spring.
Stiff toward
stroke endOil amountDecrease oil amount by about
5 cm
3 (0.2 US oz, 0.2 Imp.oz).
Soft toward
stroke end, bot-
toming outOil amountIncrease oil amount by about 5
cm
3 (0.2 US oz, 0.2 Imp.oz).
Stiff initial
movementCompression
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.

CHASSIS
4-7
EAS2GB2151SUSPENSION SETTING (REAR SHOCK ABSORBER)
TIP
• If any of the following symptoms is experienced with the standard position as the base, make reset-
ting by reference to the adjustment procedure given in the same chart.
• Adjust the rebound damping in 2-click increments or decrements.
• Adjust the low compression damping in 1-click increments or decrements.
• Adjust the high compression damping in 1/6 turn increments or decrements. Low front, tend-
ing to lower
front postureCompression
damping forceTurn adjuster clockwise (about
2 clicks) to increase damping.
Rebound
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Balance with
rear endSet sunken length for 95–100
mm (3.7–3.9 in) when one
passenger is astride seat (low-
er rear posture).
Oil amount Increase oil amount by about 5
cm
3 (0.2 US oz, 0.2 Imp.oz).
“Obtrusive”
front, tending to
upper front pos-
tureCompression
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Balance with
rear endSet sunken length for 90–95
mm (3.5–3.7 in) when one
passenger is astride seat (up-
per rear posture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about
5–10 cm
3 (0.2–0.3 US oz, 0.2–
0.4 Imp.oz).
SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap
Stiff, tending to
sinkRebound
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Spring set
lengthSet sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spongy and un-
stableRebound
damping forceTurn adjuster clockwise (about
2 clicks) to increase damping.
Low compres-
sion dampingTurn adjuster clockwise (about
1 click) to increase damping.
Spring Replace with stiff spring. SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap

CHASSIS
4-8
Heavy and
draggingRebound
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Spring Replace with soft spring.
Poor road grip-
pingRebound
damping forceTurn adjuster counterclock-
wise (about 2 clicks) to de-
crease damping.
Low compres-
sion dampingTurn adjuster clockwise (about
1 click) to increase damping.
High compres-
sion dampingTurn adjuster clockwise (about
1/6 turn) to increase damping.
Spring set
lengthSet sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with soft spring.
Bottoming outHigh compres-
sion dampingTurn adjuster clockwise (about
1/6 turn) to increase damping.
Spring set
lengthSet sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with stiff spring.
BouncingRebound
damping forceTurn adjuster clockwise (about
2 clicks) to increase damping.
Spring Replace with soft spring.
Stiff travelHigh compres-
sion dampingTurn adjuster counterclock-
wise (about 1/6 turn) to de-
crease damping.
Spring set
lengthSet sunken length for 90–100
mm (3.5–3.9 in) when one
passenger is astride seat.
Spring Replace with soft spring. SymptomSection
Check Adjust
JumpLarge
gapMedi-
um
gapSmall
gap

REAR WHEEL
5-10
EAS2GB2163REMOVING THE REAR WHEEL
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 wheel axle nut “1”
3. Loosen:
• Locknut “2”
4. Tighten:
• Adjusting bolt “3”
5. Remove:
• Rear wheel axle
• Rear wheel
TIP
• Push the rear wheel forward and remove the
drive chain from the rear wheel sprocket.
• Do not depress the brake pedal with the rear
wheel removed.
EAS2GB2164CHECKING THE REAR WHEEL
1. Check:
• Rear wheel axle
• Rear wheel
• Bearing
• Oil seals
Refer to “CHECKING THE FRONT WHEEL”
on page 5-5.
2. Check:
•Tire(s)
• Rear wheel
Damage/wear  Replace.
Refer to “CHECKING THE TIRES” on page
3-35 and “CHECKING THE WHEELS” on
page 3-36.
3. Check:
• Spokes
Refer to “CHECKING THE FRONT WHEEL”
on page 5-5.4. Measure:
• Radial wheel runout
• Lateral wheel runout
Refer to “CHECKING THE FRONT WHEEL”
on page 5-5.
EAS2GB2165DISASSEMBLING THE REAR WHEEL
1. Remove:
• Oil seals
• Bearing
Refer to “DISASSEMBLING THE FRONT
WHEEL” on page 5-6.
EAS2GB2166CHECKING AND REPLACING THE REAR
WHEEL SPROCKET
1. Check:
• Rear wheel sprocket
More than 1/4 tooth wear “a”  Replace the
rear wheel sprocket and the drive sprocket
as a set.
Bent tooth  Replace the rear wheel
sprocket and the drive sprocket as a set.
2. Replace:
• Rear wheel sprocket
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a. Remove the self-locking nuts and the rear
wheel sprocket.
b. Clean the rear wheel drive hub with a clean
cloth, especially the surfaces that contact
the sprocket.
c. Install the new rear wheel sprocket.
3
12
Radial wheel runout limit
2.0 mm (0.08 in)
Lateral wheel runout limit
2.0 mm (0.08 in)
b. Correct
1. Drive chain roller
2. Rear wheel sprocket
Rear wheel sprocket self-locking
nut
50 Nm (5.0 m·kgf, 36 ft·lbf)
T R..