2014 YAMAHA WR 250F oil pressure

3-20
CHASSIS
CHECKING THE BRAKE FLUID
LEVEL
1. Place the brake master cylinder
so that its top is in a horizontal po-
sition.
2. Inspect:
• Brake fluid level
Fluid at lower level→Fill up.
• Use only designated quality
brake fluid to avoid poor brake
performance.
• Refill with same type and brand
of brake fluid; mixing fluids
could result in poor brake perfor-
mance.
• Be sure that water or other con-
taminants do not enter master
cylinder when refilling.
• Clean up spilled fluid immediate-
ly to avoid erosion of painted
surfaces or plastic parts.
a. Lower level
A. Front
B. Rear
CHECKING THE SPROCKET
1. Inspect:
• Sprocket teeth "a"
Excessive wear→Replace.
Replace the drive sprocket, rear
wheel sprocket and drive chain as a
set.
CHECKING THE DRIVE CHAIN
1. Measure:
• Drive chain length (15 links) "a"
Out of specification→Replace.
• While measuring the drive chain
length, push down on the drive
chain to increase its tension.
• Measure the length between drive
chain roller "1" and "16" as shown.
• Perform this measurement at two or
three different places.
2. Remove:
• Drive chain "1"
Remove the drive chain using a drive
chain cutter "2".
3. Clean:
• Drive chain
Brush off as much dirt as possi-
ble. Then clean the drive chain
using the chain cleaner.
This machine has a drive chain
with small rubber O-rings "1" be-
tween the side plates. Steam
cleaning, high-pressure washes,
certain solvent and kerosene can
damage these O-rings.
4. Inspect:
• O-ring "1" (drive chain)
Damage→Replace the drive
chain.
•Roller "2"
• Side plate "3"
Damage/wear→Replace the
drive chain.
5. Check:
• Drive chain stiffness "a"
Clean and oil the drive chain and
hold as illustrated.
Stiff→Replace the drive chain.
6. Install:
• Chain joint "1"
• O-ring "2"
• Drive chain "3"
• Link plate "4"
When installing the drive chain, apply
the lithium soap base grease on the
chain joint and O-rings.
7. Install:
• Link plate
• Press the link plate onto the chain
joint using a drive chain riveter "5".
• Rivet the end of the chain joint us-
ing a drive chain riveter.
• After riveting the chain joint, make
sure its movement is smooth.
Recommended brake flu-
id:
DOT #4
Drive chain length (15
links):
: 239.3 mm
(9.42 in)

3-21
CHASSIS
8. Lubricate:
• Drive chain
ADJUSTING THE DRIVE CHAIN
SLACK
1. Elevate the rear wheel by placing
the suitable stand under the en-
gine.
2. Check:
• Drive chain slack "a"
Above the seal guard installation
bolt.
Out of specification→Adjust.
Before checking and/or adjusting, ro-
tate the rear wheel through several
revolutions and check the slack sev-
eral times to find the tightest point.
Check and/or adjust the drive chain
slack with the rear wheel in this "tight
chain" position.
3. Adjust:
• Drive chain slack
Drive chain slack adjustment
steps:
a. Loosen the axle nut "1" and lock-
nuts "2".b. Adjust the drive chain slack by
turning the adjusters "3".
c. Turn each adjuster exactly the
same amount to maintain correct
axle alignment. (There are marks
"a" on each side of the drive chain
puller alignment.) NOTICE: Im-
proper drive chain slack will
overload the engine as well as
other vital parts of the motorcy-
cle and can lead to chain slip-
page or breakage. To prevent
this from occurring, keep the
drive chain slack within the
specified limits.
Turn the adjuster so that the drive
chain is in line with the sprocket, as
viewed from the rear.
d. Tighten the axle nut while pushing
down the drive chain.
e. Tighten the locknuts.
CHECKING THE FRONT FORK
1. Inspect:
• Front fork smooth action
Operate the front brake and
stroke the front fork.
Unsmooth action/oil leakage→
Repair or replace.CLEANING THE FRONT FORK OIL
SEAL AND DUST SEAL
1. Remove:
•Protector
• Dust seal "1"
Use a thin screw driver, and be care-
ful not to damage the inner fork tube
and dust seal.
2. Clean:
• Dust seal "a"
• Oil seal "b"
• Clean the dust seal and oil seal af-
ter every run.
• Apply the lithium soap base grease
on the inner tube.
RELIEVING THE FRONT FORK
INTERNAL PRESSURE
If the front fork initial movement feels
stiff during a run, relieve the front fork
internal pressure.
1. Elevate the front wheel by placing
a suitable stand under the engine.
2. Remove the air bleed screw "1"
and release the internal pressure
from the front fork.
3. Install:
• Air bleed screw Drive chain lubricant:
SAE 10W-40 motor oil
or suitable chain lubri-
cants
Drive chain slack:
48.0–58.0 mm (1.89–
2.28 in)
To tighten→Turn the adjuster "3"
counterclockwise.
To loosen→Turn the adjuster "3"
clockwise and push wheel for-
ward.
Axle nut:
125 Nm (12.5 m•kg, 90
ft•lb)
Locknut:
19 Nm (1.9 m•kg, 13
ft•lb)
Air bleed screw:
1 Nm (0.1 m•kg, 0.7
ft•lb)

4-5
CHASSIS
CHASSIS
SELECTION OF THE SECONDARY
REDUCTION RATIO (SPROCKET)
ondary gear reduction ratio>
• It is generally said that the second-
ary gear ratio should be reduced for
a longer straight portion of a speed
course and should be increased for
a course with many corners. Actual-
ly, however, as the speed depends
on the ground condition of the day
of the ride, be sure to run through
the circuit to set the machine suit-
able for the entire course.
• In actuality, it is very difficult to
achieve settings suitable for the en-
tire course and some settings may
be sacrificed. Thus, the settings
should be matched to the portion of
the course that has the greatest ef-
fect on the ride result. In such a
case, run through the entire course
while making notes of lap times to
find the best balance; then, deter-
mine the secondary reduction ratio.
• If a course has a long straight por-
tion where a machine can run at
maximum speed, the machine is
generally set such that it can devel-
op its maximum revolutions toward
the end of the straight line, with care
taken to avoid the engine over-rev-
ving.
Riding technique varies from rider to
rider and the performance of a ma-
chine also vary from machine to ma-
chine. Therefore, do not imitate other
rider's settings from the beginning but
choose your own setting according to
the level of your riding technique.
DRIVE AND REAR WHEEL
SPROCKETS SETTING PARTS
For EUROPE
For AUS and NZ
For ZATIRE PRESSURE
Tire pressure should be adjust to suit
the road surface condition of the cir-
cuit.
• Under a rainy, muddy, sandy, or
slippery condition, the tire pressure
should be lower for a larger area of
contact with the road surface.
• Under a stony or hard road condi-
tion, the tire pressure should be
higher to prevent a flat tire.
FRONT FORK SETTING
The front fork setting should be made
depending on the rider's feeling of an
actual run and the circuit conditions.
The front fork setting includes the fol-
lowing three factors:
1. Setting of air spring characteris-
tics
• Change the fork oil level.
2. Setting of spring preload
• Change the spring.
• Install the adjustment washer.
3. Setting of damping force
• Change the compression damp-
ing.
• Change the rebound damping.
The spring acts on the load and
the damping force acts on the
cushion travel speed. Secondary reduction ratio =
Number of rear wheel sprocket
teeth/Number of drive sprocket
teeth
Standard secondary
reduction ratio47/14
(3.357)
* 50/13
(3.846)
* For AUS, NZ and ZA
Part
nameSize Part number
Drive
sprocket
"1"
13T 9383B-13218
(STD) 14T 9383B-14222
Rear
wheel
sprocket
"2"
(STD) 47T 1C3-25447-00
48T 5GS-25448-50
50T 5TJ-25450-80
52T 5TJ-25452-80
Part
nameSize Part number
Drive
sprocket
"1"
(STD) 13T 9383B-13218
14T 9383B-14222
Rear
wheel
sprocket
"2"
48T 1C3-25448-00
49T 1C3-25449-00
(STD) 50T 1C3-25450-00
51T 1C3-25451-00
52T 1C3-25452-00
Part
nameSize Part number
Drive
sprocket
"1"
(STD) 13T 9383B-13218
Rear
wheel
sprocket
"2"
48T 5GS-25448-50
(STD) 50T 5TJ-25450-80
52T 5TJ-25452-80
Standard tire pressure:
100 kPa (1.00 kgf/cm2,
15 psi)
Extent of adjustment:
60–80 kPa (0.60–0.80
kgf/cm
2, 9.0–12 psi)
Extent of adjustment:
100–120 kPa (1.00–1.20
kgf/cm
2, 15–18 psi)

4-6
CHASSIS
CHANGE IN LEVEL AND
CHARACTERISTICS OF FORK OIL
Damping characteristic near the final
stroke can be changed by changing
the fork oil amount.
Adjust the oil level in 5 mm (0.2 in)
increments or decrements. Too
low oil level causes the front fork
to produce a noise at full rebound
or the rider to feel some pressure
on his hands or body. Alternative-
ly, too high oil level will develop
unexpectedly early oil lock with
the consequent shorter front fork
travel and deteriorated perfor-
mance and characteristics. There-
fore, adjust the front fork within
the specified range.
A. Air spring characteristics in
relation to oil level change
B. Load
C. Stroke
1. Max. oil level
2. Standard oil level
3. Min. oil levelADJUSTING THE SPRING
PRELOAD
The spring preload is adjusted by in-
stalling the adjustment washer "1" be-
tween the fork spring "2" and damper
rod "3".
Do not install three or more adjust-
ment washers for each front fork.
Always adjust each front fork to
the same setting. Uneven adjust-
ment can cause poor handling and
loss of stability.
A. Load
B. Fork stroke
1. Without adjustment washer
(standard)
2. 1 adjustment washer
3. 2 adjustment washers
SETTING OF SPRING AFTER
REPLACEMENT
As the front fork setting can be easily
affected by rear suspension, take
care so that the machine front and
rear are balanced (in position, etc.)
when setting the front fork.
1. Use of soft spring
• Change the rebound damping.
Turn out one or two clicks.
• Change the compression damp-
ing.
Turn in one or two clicks.
Generally a soft spring gives a soft
riding feeling. Rebound damping
tends to become stronger and the
front fork may sink deeply over a se-
ries of gaps.
2. Use of stiff spring
• Change the rebound damping.
Turn in one or two clicks.
• Change the compression damp-
ing.
Turn out one or two clicks.
Generally a stiff spring gives a stiff
riding feeling. Rebound damping
tends to become weaker, resulting in
lack of a sense of contact with the
road surface or in a vibrating handle-
bar.
FRONT FORK SETTING PARTS
• Adjustment washer "1"
• Front fork spring "2"
The I.D. mark (slits) "a" is proved on
the end of the spring.
When using a spring with a spring
rate of 0.469 kg/mm, do not install
two or more adjustment washers
for each front fork.
Standard oil level:
132.0 mm (5.20 in)
Extent of adjustment:
95.0–150.0 mm (3.74–
5.91 in)
From top of outer tube
with inner tube and
damper rod fully com-
pressed without
spring.
Standard washer quanti-
ty:
Zero adjustment wash-
ers
Extent of adjustment:
Zero–2 adjustment
washers
TYPE (thick-
ness)PART NUMBER
T = 2.3 mm (0.09
in)5XE-23364-00
TYPESPRI
NG
RATESPRING
PART
NUMBER
(-23141-)I.D.
MARK
(slits)
SOFT0.408 5TJ-00 |
0.418 5TJ-10 ||
0.428 5TJ-20 |||
0.438 5TJ-30 ||||
STD 0.449 5TJ-A0 —
STIFF0.459 5TJ-50 |-|
0.469 5TJ-60 |-||

5-29
CLUTCH
CLUTCH
REMOVING THE CLUTCH
Order Part name Q'ty Remarks
Drain the engine oil. Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Brake pedal Refer to "ENGINE REMOVAL" section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Clutch spring 5
3 Pressure plate 1
4 Push rod 1 1
5 Circlip 1
6 Washer 1
7 Bearing 1
8Ball 1
9 Push rod 2 1
10 Friction plate 9
11 Clutch plate 8
12 Cushion spring 1
13 Seat plate 1

5-32
CLUTCH
INSTALLING THE CLUTCH
1. Install:
• Primary driven gear "1"
• Thrust washer "2"
• Clutch boss "3"
Apply the engine oil on the primary
driven gear inner circumference.
2. Install:
• Lock washer "1"
• Nut (clutch boss) "2"
Use the clutch holding tool "3" to hold
the clutch boss.
A. For USA and CDN
B. Except for USA and CDN
3. Bend the lock washer "1" tab.
4. Install:
• Seat plate "1"
• Cushion spring "2"
• Install the seat plate with its cham-
fered portion "a" facing the clutch
boss "3".
• Install the seat plate so that it is not
caught on the step "b".
• Install the cushion spring with the
paint "c" facing out.
5. Install:
• Friction plate 1 "1"
• Clutch plate 1 "2"
• Friction plate 2 "3"
• Clutch plate 2 "4"
• Install the clutch plates and friction
plates alternately on the clutch
boss, starting with a friction plate
and ending with a friction plate.
• Use the friction plates 1 for the first
and final while paying attention to
the difference in surface pattern.
• Apply the engine oil on the friction
plates and clutch plates.
• Unlike the clutch plate 2, the clutch
plate 1 has no surface gloss. Use
the clutch plate 1 for the first while
paying attention to the difference in
surface gloss.
6. Install:
•Bearing "1"
• Washer "2"
• Circlip "3"
To push rod 1 "4".
Apply the engine oil on the bearing
and washer.
7. Install:
• Push rod 2 "1"
•Ball "2"
• Push rod 1 "3"
Apply the engine oil on the push rod
1, 2 and ball.
8. Install:
• Pressure plate "1"
9. Install:
• Clutch spring "1"
• Bolt (clutch spring) "2"
Tighten the bolts in stage, using a
crisscross pattern.
Nut (clutch boss):
75 Nm (7.5 m•kg, 54
ft•lb)
Clutch holding tool:
YM-91042/90890-04086
Bolt (clutch spring):
10 Nm (1.0 m•kg, 7.2
ft•lb)

6-38
REAR SHOCK ABSORBER
HANDLING NOTE
• Support the machine securely so
there is no danger of it falling
over.
• This rear shock absorber is pro-
vided with a separate type tank
filled with high-pressure nitro-
gen gas. To prevent the danger
of explosion, read and under-
stand the following information
before handling the shock ab-
sorber. The manufacturer can
not be held responsible for prop-
erty damage or personal injury
that may result from improper
handling.
• Never tamper or attempt to dis-
assemble the cylinder or the
tank.
• Never throw the rear shock ab-
sorber into an open flame or
other high heat. The rear shock
absorber may explode as a re-
sult of nitrogen gas expansion
and/ or damage to the hose.
• Be careful not to damage any
part of the gas tank. A damaged
gas tank will impair the damp-
ing performance or cause a
malfunction.
• Take care not to scratch the
contact surface of the piston
rod with the cylinder; or oil
could leak out.
• Never attempt to remove the
plug at the bottom of the nitro-
gen gas tank. It is very danger-
ous to remove the plug.
• When scrapping the rear shock
absorber, follow the instruc-
tions on disposal.
NOTES ON DISPOSAL (YAMAHA
DEALERS ONLY)
Before disposing the rear shock ab-
sorber, be sure to extract the nitrogen
gas from valve "1". Wear eye protec-
tion to prevent eye damage from es-
caping gas and/or metal chips.
To dispose of a damaged or worn-
out rear shock absorber, take the
unit to your Yamaha dealer for this
disposal procedure.
REMOVING THE BEARING
1. Remove:
• Stopper ring (upper bearing) "1"
Press in the bearing while pressing its
outer race and remove the stopper
ring.
2. Remove:
• Upper bearing "1"
Remove the bearing by pressing its
outer race.
3. Remove:
• Lower bearing "1"
Remove the bearing by pressing its
outer race.
CHECKING THE REAR SHOCK
ABSORBER
1. Inspect:
• Damper rod "1"
Bends/damage→Replace rear
shock absorber assembly.
• Shock absorber "2"
Oil leaks→Replace rear shock
absorber assembly.
Gas leaks→Replace rear shock
absorber assembly.
• Spring "3"
Damage→Replace spring.
Fatigue→Replace spring.
Move spring up and down.
• Spring guide "4"
Wear/damage→Replace spring
guide.
• Bearing "5"
Free play exists/unsmooth revolu-
tion/rust →Replace.
INSTALLING THE BEARING
1. Install:
• Upper bearing "1"
Install the bearing parallel until the
stopper ring groove appears by
pressing its outer race.
Do not apply the grease on the
bearing outer race because it will
wear the rear shock absorber sur-
face on which the bearing is press
fitted.