2010 YAMAHA WR 250F checking oil

6-19
FRONT FORK
CHECKING THE INNER TUBE
1. Inspect:• Inner tube surface "a"Score marks →Repair or replace.
Use #1,000 grit wet sandpaper.
Damaged oil lock piece →Re-
place.
• Inner tube bends Out of specification →Replace.
Use the dial gauge "1".
The bending value is shown by one
half of the dial gauge reading.
Do not attempt to straighten a bent
inner tube as this may dangerous-
ly weaken the tube.
CHECKING THE OUTER TUBE
1. Inspect:
• Outer tube "1"Score marks/wear/damage →Re-
place.
CHECKING THE FRONT FORK
CAP BOLT
1. Inspect: • Front fork cap bolt "1"
• O-ring "2"
• Air bleed screw "3"Wear/damage →Replace. ASSEMBLING THE FRONT FORK
1. Wash the all parts in a clean sol-
vent.
2. Install:
• Damper rod "1"To inner tube "2".
To install the damper rod into the
inner tube, hold the inner tube
aslant. If the inner tube is held ver-
tically, the damper rod may fall into
it, damaging the valve inside.
3. Install:• Copper washer "1"
• O-ring "2"
• Base valve "3"To inner tube "4".
4. Tighten: • Base valve "1"
• Use a damper rod holder "2" to lock the damper rod "3".
• Apply the LOCTITE
® on the base
valve thread.
5. Install:
• Spring guide "1"
• Locknut "2"To damper rod "3".
• Install the spring guide with its
smaller dia.end "a" facing down-
ward.
• With its thread "b" facing upward,
fully finger tighten the locknut onto
the damper rod.
6. Install:• Dust seal "1"
• Stopper ring "2"
• Oil seal "3"
• Oil seal washer "4"
• Slide metal "5" To inner tube "6".
• Apply the fork oil on the inner tube.
• When installing the oil seal, use vi-nyl seat "a" with fork oil applied to
protect the oil seal lip.
• Install the oil seal with its manufac- ture's marks or number facing the
axle holder side.
• Install the oil seal washer with its projections "b" facing upward.
Inner tube bending limit:
0.2 mm (0.008 in)
Base valve:55 Nm (5.5 m•kg, 40
ft•lb)
Damper rod holder: YM-01494/90890-01494

6-21
FRONT FORK
19. Wait ten minutes until the air bub-bles have been removed from the
front fork, and the oil has dis-
pense evenly in system before
setting recommended oil level.
Fill with the fork oil up to the top end
of the outer tube, or the fork oil will not
spread over to every part of the front
forks, thus making it impossible to ob-
tain the correct level.
Be sure to fill with the fork oil up to the
top of the outer tube and bleed the
front forks.
20. Measure:• Oil level (left and right) "a" Out of specification →Adjust.
Be sure to install the spring guide "2"
when checking the oil level.
Never fail to make the oil level ad-
justment between the maximum
and minimum level and always ad-
just each front fork to the same
setting. Uneven adjustment can
cause poor handling and loss of
stability.
21. Measure:
• Distance "a"Out of specification →Turn into
the locknut.
22. Loosen: • Rebound damping adjuster "1"
• Loosen the rebound damping ad-juster finger tight.
• Record the set position of the ad- juster (the amount of turning out the
fully turned in position).
23. Install:• Push rod "1"
• Fork spring "2"
• Install the fork spring with the damper rod "3" pulled up.
• After installing the fork spring, hold
the damper rod end so that it will not
go down.
24. Install:• Spring seat "1"
• Front fork cap bolt "2"
Fully finger tighten the front fork cap
bolt onto the damper rod.
25. Tighten:• Front fork cap bolt (locknut) "1"
Hold the locknut "2" and tighten the
front fork cap bolt with specified
torque.
26. Install:• Front fork cap bolt "1"To outer tube.
Temporarily tighten the cap bolt.
27. Install:• Protector guide "1"
Install the protector guide with its wid-
er side "a" facing downward.
Standard oil level:
132 mm (5.20 in)
Extent of adjustment: 95–150 mm (3.74–5.91
in)
From top of outer tube
with inner tube and
damper rod "1" fully
compressed without
spring.
Distance "a":
18 mm (0.71 in) or more
Between damper rod
"1" top and locknut "2"
top.
Front fork cap bolt (lock-
nut): 29 Nm (2.9 m•kg, 21
ft•lb)

6-24
HANDLEBAR
REMOVING THE BRAKE MASTER
CYLINDER
1. Remove:• Brake master cylinder bracket "1"
• Brake master cylinder "2"
• Do not let the brake master cylin-der hang on the brake hose.
• Keep the brake master cylinder
cap side horizontal to prevent air
from coming in.
REMOVING THE GRIP
1. Remove:•Grip "1"
Blow in air between the handlebar or
tube guide and the grip. Then remove
the grip which has become loose.
CHECKING THE HANDLEBAR
1. Inspect:• Handlebar "1"Bends/cracks/damage →Re-
place.
Do not attempt to straighten a bent
handlebar as this may dangerous-
ly weaken the handlebar.
INSTALLING THE HANDLEBAR
1. Install: • Handlebar lower holder "1"
• Washer "2"
• Nut (handlebar lower holder) "3"
• Install the handlebar lower holder with its side having the greater dis-
tance "a" from the mounting bolt
center facing forward.
• Apply the lithium soap base grease on the thread of the handlebar low-
er holder.
• Installing the handlebar lower hold- er in the reverse direction allows the
front-to-rear offs et amount of the
handlebar position to be changed.
• Do not tighten the nut yet.
2. Install: • Handlebar "1"
• Handlebar upper holder "2"
• Bolt (handlebar upper holder) "3"
• The handlebar upper holder should be installed with the punched mark
"a" forward.
• Install the handlebar so that the marks "b" are in place on both
sides.
• Install the handlebar so that the pro- jection "c" of the handlebar upper
holder is positioned at the mark on
the handlebar as shown.
• First tighten the bolts on the front side of the handlebar upper holder,
and then tighten the bolts on the
rear side.
3. Tighten:
• Nut (handlebar lower holder) "1"
4. Install: • Left grip "1"
Apply the adhesive to the handle-
bar "2".
• Before applying the adhesive, wipe off grease or oil on the handlebar
surface "a" with a lacquer thinner.
• Install the left grip to the handlebar so that the line "b" between the two
arrow marks faces straight upward.
Bolt (handlebar upper
holder): 28 Nm (2.8 m•kg, 20
ft•lb)
Nut (handlebar lower
holder): 34 Nm (3.4 m•kg, 24
ft•lb)

6-33
SWINGARM
HANDLING NOTE
Support the machine securely so
there is no danger of it falling over.
REMOVING THE CAP
1. Remove:• Left cap "1"
Remove with a slotted-head screw-
driver inserted under the mark "a" on
the left cap.
REMOVING THE BEARING
1. Remove:• Bearing "1"
Remove the bearing by pressing its
outer race.
CHECKING THE SWINGARM
1. Inspect:
• Bearing "1"
• Bushing "2"Free play exists/unsmooth revolu-
tion/rust →Replace bearing and
bushing as a set.
2. Inspect:
• Oil seal "3"Damage →Replace. CHECKING THE RELAY ARM
1. Inspect:
•Bearing "1"
• Collar "2"
Free play exists/unsmooth revolu-
tion/rust → Replace bearing and
collar as a set.
2. Inspect: • Oil seal "3"Damage →Replace.
CHECKING THE CONNECTING
ROD
1. Inspect: •Bearing "1"
• Collar "2"Free play exists/unsmooth revolu-
tion/rust →Replace bearing and
collar as a set.
2. Inspect: • Oil seal "3"
Damage →Replace.
INSTALLING THE BEARING AND
OIL SEAL
1. Install: •Bearing "1"
• Oil seal "2"
To swingarm.
• Apply the molybdenum disulfide grease on the bearing when install-
ing.
• Install the bearing by pressing it on the side having the manufacture's
marks or numbers.
• First install the outer and then the
inner bearings to a specified depth
from inside.
2. Install: • Bearing "1"
• Washer "2"
• Oil seal "3"To relay arm.
• Apply the molybdenum disulfide grease on the bearing when install-
ing.
• Install the bearing by pressing it on the side having the manufacture's
marks or numbers.
• Apply the molybdenum disulfide
grease on the washer.
3. Install:• Bearing "1"
• Oil seal "2"
To connecting rod.
Installed depth of bear-
ings: Outer "a": Zero mm
(Zero in)
Inner "b": 6.5 mm (0.26
in)
Installed depth of bear-
ings "a": Zero mm (Zero in)

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 follow ing 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.

7-3
IGNITION SYSTEM
IGNITION SYSTEM
INSPECTION STEPS
Use the following steps for checking the possibility of the malfunctioning engine being attributable to ignition system failure
and for checking the spark plug which will not spark.
*1 marked: Refer to "CHECKING TH E FUSE" section in the CHAPTER 3.
*2 marked: Refer to "CHECKING AND CHARGIN G THE BATTERY" section in the CHAPTER 3.
*3 marked: Only when the ignition checker is used.
• Remove the following parts before inspection.
1. Seat
2. Fuel tank
• Use the following special tools in this inspection.
*1 Check fuse. No good→Replace fuse and check wire harness.
OK ↓
*2 Check battery. No good→Recharge or replace.
OK ↓
Spark gap test Spark→ *3 Clean or replace spark plug.
No spark ↓
Check entire ignition system for connection.
(couplers, leads and ignition coil) No good
→
Repair or replace.
OK ↓
Check engine stop switch. No good→Replace.
OK ↓
Check main switch. No good→Replace.
OK ↓
Check ignition coil. (primary coil and secondary
coil) No good
→
Replace.
OK ↓
Check AC magneto. (pickup coil) No good→Replace.
OK ↓
Check neutral switch. No good→Repair or replace.
OK ↓
Replace CDI unit.
Dynamic spark tester: YM-34487
Ignition checker: 90890-06754
Pocket tester: YU-3112-C/90890-03112

7-4
IGNITION SYSTEM
SPARK GAP TEST
1. Disconnect the ignition coil from spark plug.
2. Remove the ignition coil cap.
3. Connect the dynamic spark tester "1" (ignition ch ecker "2") as
shown.
• Ignition coil "3"
• Spark plug "4"
A. For USA and CDN
B. Except for USA and CDN
4. Kick the kickstarter crank.
5. Check the ignition spark gap.
6. Start engine, and increase spark gap until misfire occurs. (for USA
and CDN only)
CHECKING THE COUPLERS,
LEADS AND IGNITION COIL
CONNECTION
1. Check: • Couplers and leads connection
Rust/dust/looseness/short-circuit
→ Repair or replace.
• Ignition coil and spark plug as
they are fitted
Push in the ignition coil until it
closely contacts the spark plug
hole in the cylinder head cover. CHECKING THE ENGINE STOP
SWITCH
1. Inspect:
• Engine stop switch conduction
Not conductive while it is pushed →
Replace.
Conductive while it is freed →Re-
place.
Set the tester selection position to " Ω
× 1".
2. Inspect: • Rubber part "a"Tears/damage → Replace.
CHECKING THE MAIN SWITCH
1. Inspect: • Main switch conduction
Not conductive while the main switch
is moved to "ON" →Replace.
Conductive while the main switch is
moved to "OFF" →Replace.
Set the tester selection position to " Ω
×1".
2. Inspect: • Main switch indicator light
Use 12 V battery.
Indicator light does not come on →
Replace.
3. Inspect:
• Rubber part "a"Tears/damage →Replace.
CHECKING THE IGNITION COIL
1. Remove the ignition coil cap.
2. Inspect: • Primary coil resistanceOut of specification →Replace.
Minimum spark gap:
6.0 mm (0.24 in)
Tester (+) lead →Black lead "1"
Tester (-) lead →Black lead "2"
Result Conductive (while the
engine stop switch is
pushed)
Tester (+) lead →Red lead "1"
Tester (-) lead →Brown lead "2"
Result Conductive (while the
main switch is moved
to "ON")
Battery (+) lead →Red/Black lead
"1"
Battery (-) lead →Black lead "2"
Tester (+) lead →Orange lead "1"
Tester (-) lead →Black lead "2"
Primary
coil resis- tance Tester se-
lector posi- tion
0.08–0.10
Ω at 20 °C (68 °F) Ω × 1

7-5
ELECTRIC STARTING SYSTEM
3. Inspect:• Secondary coil resistanceOut of specification →Replace.
4. Inspect: • Sealed portion of ignition coil "a"
• Spark plug terminal pin "b"
• Threaded portion of spark plug "c"Wear →Replace.
CHECKING THE AC MAGNETO
1. Inspect: • Pickup coil resistance
Out of specification →Replace. CHECKING THE NEUTRAL
SWITCH
1. Inspect:
• Neutral switch conduction
Not conductive while it is in neutral →
Replace.
Conductive while it is engaged →Re-
place.
Set the tester selection position to " Ω
× 1".
CHECKING THE CDI UNIT
Check all electrical components. If no
fault is found, replace the CDI unit.
Then check the electrical compo-
nents again.
ELECTRIC STARTING
SYSTEM
STARTING CIRCUIT CUT-OFF
SYSTEM OPERATION
If the main switch is set to "ON", the
starter motor can only operate if at
least one of the following conditions is
met:
• The transmission is in neutral (the neutral switch is closed).
• The clutch lever is pulled to the han- dlebar (the clutch switch is closed).
The starting circuit cut-off relay pre-
vents the starter motor from operating
when neither of these conditions has
been met. In this instance, the start-
ing circuit cut-off relay is open so cur-
rent cannot reach the starter motor.
When at least one of the above con-
ditions has been met the starting cir-
cuit cut-off relay is closed and the
engine can be started by pressing the
start switch.
WHEN THE TRANSMISSION IS IN
NEUTRAL
WHEN THE CLUTCH LEVER IS
PULLED TO THE HANDLEBAR 1. Battery
2. Main fuse
3. Main switch
4. Starting circuit cut-off relay
5. Start switch
6. Diode
7. Clutch switch
8. Neutral switch
9. Starter relay
10. Starter motor
Tester (+) lead
→Orange lead "1"
Tester (-) lead →Spark plug termi-
nal "2"
Secondary coil resis- tance Tester se-
lector posi- tion
4.6–6.8
k Ωat 20 °C
(68 °F) k
Ω × 1
Tester (+) lead →Red lead "1"
Tester (-) lead →White lead "2"
Pickup coil resistance Tester se-
lector posi-
tion
248–372 Ω
at 20 °C (68 °F) Ω × 100
Tester (+) lead
→Sky blue lead "1"
Tester (-) lead →Ground "2"
Result Conductive (while gear
is in neutral)