2008 YAMAHA WR 250R engine

PERIODIC MAINTENANCE AND MINOR REPAIR
6-18
1
2
3
4
5
6
7
8
9

EAU21382
Checking the throttle cable
free play
The throttle cable free play should mea-
sure 3.0–5.0 mm (0.12–0.20 in) at the
throttle grip. Periodically check the
throttle cable free play and, if neces-
sary, have a Yamaha dealer adjust it.
EAU21401
Valve clearance
The valve clearance changes with use,
resulting in improper air-fuel mixture
and/or engine noise. To prevent this
from occurring, the valve clearance
must be adjusted by a Yamaha dealer
at the intervals specified in the periodic
maintenance and lubrication chart.
EAU21640
Tires
To maximize the performance, durabil-
ity, and safe operation of your motorcy-
cle, note the following points regarding
the specified tires.
Tire air pressure
The tire air pressure should be checked
and, if necessary, adjusted before each
ride.
WARNING

EWA10500

The tire air pressure must be
checked and adjusted on cold
tires (i.e., when the temperature
of the tires equals the ambient
temperature).

The tire air pressure must be ad-
justed in accordance with the
riding speed and with the total
weight of rider, passenger, car-
go, and accessories approved
for this model.
1. Throttle cable free play
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-25
2
3
4
5
67
8
9

EAU22760
Drive chain slack
The drive chain slack should be
checked before each ride and adjusted
if necessary.
EAU22773
To check the drive chain slack
1. Place the motorcycle on the side-
stand.
NOTE:

When checking and adjusting the drive
chain slack, there should be no weight
on the motorcycle.
2. Shift the transmission into the neu-
tral position.
3. Move the rear wheel by pushing
the motorcycle to locate the tight-
est portion of the drive chain, and
then measure the drive chain slack
as shown.4. If the drive chain slack is incorrect,
adjust it as follows.
EAU22942
To adjust the drive chain slack
1. Loosen the axle nut and the lock-
nut on each side of the swingarm.
2. To tighten the drive chain, turn the
adjusting bolt on each side of the
swingarm in direction (a). To loos-
en the drive chain, turn the adjust-
ing bolt on each side of the
swingarm in direction (b), and then
push the rear wheel forward.
NOTE:

Using the alignment marks on each
side of the swingarm, make sure thatboth chain pullers are in the same posi-
tion for proper wheel alignment.
CAUTION:

ECA10570
Improper drive chain slack will over-
load the engine as well as other vital
parts of the motorcycle and can lead
to chain slippage or breakage. To
prevent this from occurring, keep
the drive chain slack within the
specified limits.
3. Tighten the locknuts, and then
tighten the axle nut to the specified
torque.
Drive chain slack:
38.0–48.0 mm (1.50–1.89 in)
1. Drive chain slack
1

1. Axle nut
2. Drive chain slack adjusting bolt
3. Locknut
1
23
(b)
(a)

PERIODIC MAINTENANCE AND MINOR REPAIR
6-26
1
2
3
4
5
6
7
8
9

EAU23022
Cleaning and lubricating the
drive chain
The drive chain must be cleaned and
lubricated at the intervals specified in
the periodic maintenance and lubrica-
tion chart, otherwise it will quickly wear
out, especially when riding in dusty or
wet areas. Service the drive chain as
follows.
CAUTION:

ECA10581
The drive chain must be lubricated
after washing the motorcycle and
riding in the rain.
1. Clean the drive chain with kero-
sene and a small soft brush.
CAUTION:

ECA11120
To prevent damaging the O-rings, do
not clean the drive chain with steam
cleaners, high-pressure washers or
inappropriate solvents.
2. Wipe the drive chain dry.
3. Thoroughly lubricate the drive
chain with a special O-ring chain
lubricant.
CAUTION:

ECA11110
Do not use engine oil or any other lu-
bricants for the drive chain, as they
may contain substances that could
damage the O-rings.
Tightening torque:
Axle nut:
125 Nm (12.5 m·kgf, 90.4 ft·lbf)

PERIODIC MAINTENANCE AND MINOR REPAIR
6-27
2
3
4
5
67
8
9

EAU23100
Checking and lubricating the
cables
The operation of all control cables and
the condition of the cables should be
checked before each ride, and the ca-
bles and cable ends should be lubricat-
ed if necessary. If a cable is damaged
or does not move smoothly, have a
Yamaha dealer check or replace it.
WARNING

EWA10720
Damage to the outer sheath may in-
terfere with proper cable operation
and will cause the inner cable to
rust. Replace a damaged cable as
soon as possible to prevent unsafe
conditions.
EAU23111
Checking and lubricating the
throttle grip and cable
The operation of the throttle grip should
be checked before each ride. In addi-
tion, the cable should be lubricated at
the intervals specified in the periodic
maintenance chart.
EAU44271
Checking and lubricating the
brake and shift pedals
The operation of the brake and shift
pedals should be checked before each
ride, and the pedal pivots should be lu-
bricated if necessary.
Recommended lubricant:
Engine oil

PERIODIC MAINTENANCE AND MINOR REPAIR
6-30
1
2
3
4
5
6
7
8
9
CAUTION:

ECA10590
If any damage is found or the front
fork does not operate smoothly,
have a Yamaha dealer check or re-
pair it.
EAU23280
Checking the steering
Worn or loose steering bearings may
cause danger. Therefore, the operation
of the steering must be checked as fol-
lows at the intervals specified in the pe-
riodic maintenance and lubrication
chart.
1. Place a stand under the engine to
raise the front wheel off the
ground.
WARNING

EWA10750
Securely support the vehicle so that
there is no danger of it falling over.
2. Hold the lower ends of the front
fork legs and try to move them for-
ward and backward. If any free
play can be felt, have a Yamaha
dealer check or repair the steering.

PERIODIC MAINTENANCE AND MINOR REPAIR
6-37
2
3
4
5
67
8
9

EAU24350
Supporting the motorcycle
Since this model is not equipped with a
centerstand, follow these precautions
when removing the front and rear
wheel or performing other maintenance
requiring the motorcycle to stand up-
right. Check that the motorcycle is in a
stable and level position before starting
any maintenance. A strong wooden
box can be placed under the engine for
added stability.
To service the front wheel
1. Stabilize the rear of the motorcycle
by using a motorcycle stand or, if
an additional motorcycle stand is
not available, by placing a jack un-
der the frame in front of the rear
wheel.
2. Raise the front wheel off the
ground by using a motorcycle
stand.
To service the rear wheel
Raise the rear wheel off the ground by
using a motorcycle stand or, if a motor-
cycle stand is not available, by placing
a jack either under each side of theframe in front of the rear wheel or under
each side of the swingarm.

EAU24360
Front wheel
EAU45160
To remove the front wheel
WARNING

EWA10820

It is advisable to have a Yamaha
dealer service the wheel.

Securely support the motorcy-
cle so that there is no danger of
it falling over.
1. Loosen the front wheel axle pinch
bolts and axle nut.
1. Front wheel axle pinch bolt
2. Axle nut
2
1

PERIODIC MAINTENANCE AND MINOR REPAIR
6-41
2
3
4
5
67
8
9

EAU42130
Troubleshooting charts
Starting problems or poor engine performance
WARNING

EWA10840
Keep away open flames and do not smoke while checking or working on the fuel system.
Check the fuel level in
the fuel tank.1. Fuel
There is enough fuel.
There is no fuel.
Check the compression.
Supply fuel.
The engine does not start.
Check the compression.
Operate the electric starter.2. Compression
There is compression.
There is no compression.
Check the ignition.
Have a Yamaha dealer
check the vehicle.
Remove the spark plug
and check the electrodes.3. Ignition
Wipe off with a dry cloth and correct the
spark plug gap, or replace the spark plug.
Have a Yamaha dealer check the vehicle.
The engine does not start.
Have a Yamaha dealer
check the vehicle.
The engine does not start.
Check the battery.
Operate the electric starter.4. Battery
The engine turns over
quickly.
The engine turns over
slowly.
The battery is good.Check the battery lead connections,
and charge the battery if necessary.
DryWet
Operate the electric starter.

PERIODIC MAINTENANCE AND MINOR REPAIR
6-42
1
2
3
4
5
6
7
8
9Engine overheating
WARNING

EWA10400

Do not remove the radiator cap when the engine and radiator are hot. Scalding hot fluid and steam may be
blown out under pressure, which could cause serious injury. Be sure to wait until the engine has cooled.

After removing the radiator cap retaining bolt, place a thick rag, like a towel, over the radiator cap, and then
slowly rotate the cap counterclockwise to the detent to allow any residual pressure to escape. When the hissing
sound has stopped, press down on the cap while turning it counterclockwise, and then remove the cap.
NOTE:

If coolant is not available, tap water can be temporarily used instead, provided that it is changed to the recommended coolant
as soon as possible.
Wait until the
engine has cooled.
Check the coolant level in the
reservoir and radiator.
The coolant level
is OK.The coolant level is low.
Check the cooling system
for leakage.
Have a Yamaha dealer checkand repair the cooling system.Add coolant. (See NOTE.)
Start the engine. If the engine overheats again,
have a
Yamaha dealer check
and repair the cooling system.
There is
leakage.
There is
no leakage.