2006 YAMAHA WR 250F brake

MAINTENANCE SPECIFICATIONS
2 - 15
SPEC
Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Nipple (spoke)—72 3 0.3 2.2
Rear wheel sprocket M8 × 1.25 6 50 5.0 36
Rear brake disc cover M6 × 1.0 2 7 0.7 5.1
Rear brake caliper protector M6 × 1.0 2 7 0.7 5.1
Drive chain puller adjust bolt and locknut M8 × 1.25 2 16 1.6 11
Engine mounting:
Engine and engine bracket (front) M10 × 1.25 1 69 6.9 50
Engine and frame (lower) M10 × 1.25 1 69 6.9 50
Engine bracket and frame M8 × 1.25 6 34 3.4 24
Engine and engine bracket (upper) M10 × 1.25 1 55 5.5 40
Lower engine guard M6 × 1.0 3 10 1.0 7.2
Left engine guard M8 × 1.25 2 23 2.3 17
Right engine guard M8 × 1.25 2 23 2.3 17
Regulator M6 × 1.0 2 7 0.7 5.1
Pivot shaft and nut M16 × 1.5 1 80 8.0 58
Relay arm and swingarm M14 × 1.5 1 70 7.0 50
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame (upper) M8 × 1.25 1 32 3.2 23
Rear frame (lower) M8 × 1.25 2 29 2.9 21
Swingarm and brake hose holder M5 × 0.8 4 2 0.2 1.4
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Upper drive chain tensioner M8 × 1.25 1 19 1.9 13
Lower drive chain tensioner M8 × 1.25 1 20 2.0 14
Drive chain support M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank M6 × 1.0 2 10 1.0 7.2
Fuel cock M6 × 1.0 2 6 0.6 4.3
Seat set bracket and fuel tank M6 × 1.0 1 7 0.7 5.1
Hooking screw (fitting band) and fuel tank M6 × 1.0 1 7 0.7 5.1
Fuel tank bracket and fuel tank M6 × 1.0 4 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 6 7 0.7 5.1
Air scoop and radiator guard (lower) M6 × 1.0 2 6 0.6 4.3
Front fender M6 × 1.0 4 7 0.7 5.1
Rear fender (front) M6 × 1.0 2 7 0.7 5.1
Rear fender (rear) M6 × 1.0 2 11 1.1 8.0
Side cover M6 × 1.0 2 7 0.7 5.1
Seat M8 × 1.25 2 23 2.3 17
Multi-function display bracket and upper
bracketM6 × 1.0 2 7 0.7 5.1
Multi-function display M5 × 0.8 2 4 0.4 2.9

SPEC
2 - 97
CABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Oil tank breather hose
3Clamp
4Diode
5Wire harness
6Hot starter cable
7Cylinder head breather hose
8Throttle position sensor lead
9Neutral switch lead
0Oil hoseAClutch cable
BStarter motor lead
CNegative battery lead
DCable guide
EBrake hose
FRectifier/regulator lead
GAC magneto lead
HRectifier/regulator
ICarburetor breather hoseJCarburetor overflow hose
KCoolant reservoir breather hose
ÈInsert the fuel tank breather hose into
the hole in the steering stem cap.
ÉPass the oil tank breather hose on the
outside of the AC magneto lead, neu-
tral switch lead, wire harness, starter
motor lead, negative battery lead and
cylinder head breather hose.
B
B
B-B
A
Ô3B
Ó3 Ö
C
× EF
9
GÙ
H
Ú
Û
1
È
3
Ê
4
Ë
5
6
7 Ì
ÍÎ
Ï
Ñ Ð
8
0 3
ÒÜ II
JK
9 A 2
É
0
9A
ØD ØD
Õ

SPEC
2 - 107
CABLE ROUTING DIAGRAM
1Brake master cylinder
2Brake hose holder
3Brake hoseÈInstall the brake hose so that its pipe portion directs as shown
and lightly touches the projection on the brake caliper.
ÉPass the brake hose into the brake hose holders.
ÊIf the brake hose contacts the spring (rear shock absorber),
correct its twist.
ËInstall the brake hose so that its pipe portion directs as shown
and lightly touches the projection on the brake master cylinder.

SPEC
2 - 111
CABLE ROUTING DIAGRAM
1Throttle cable
2Clamp
3Brake hose
4Hot starter cable
5Clutch cable
6Hose guide
7Speed sensor lead
8Main switch lead
9Main switch
0Multi-function display
AStart switch lead
BClutch switch lead
CEngine stop switch lead
DMulti-function display leadÈFasten the start switch lead to the han-
dlebar with the plastic bands.
ÉFasten the engine stop switch lead and
clutch switch lead to the handlebar with
the plastic bands.
ÊPass the brake hose through the hose
guides.
ËSecure the coupler by inserting it into
the multi-function display bracket.
ÌPass the main switch lead above the
multi-function display bracket.
ÍPass the throttle cables, clutch cable
and hot starter cable between the upper
bracket and multi-function display
bracket.ÎPass the multi-function display lead and
speed sensor lead between the multi-
function display and multi-function dis-
play bracket.
ÏSecure the coupler by pushing it into
the hole in the multi-function display
bracket.
ÐFasten the clutch switch lead and
engine stop switch lead to the multi-
function display bracket and cut off the
tie end. Fasten them at a location
where the tie end does not contact the
multi-function display.
ÑSecure the wire harness clip by pushing
it into the hole in the multi-function dis-
play bracket on the inside.
4
5
Î
Ê Ó
A
B
F-FE-E
CD
A
D
7 7
2
Ò Ë
A
12
È32
É
6
Ê
6
8
Ì0
9
ËÑ C
BÏ
2
Ð 8
8
1Í
4
5
4
5B2
C
DC BB A
F F
EE
EE
Ë
2

3 - 2
INSP
ADJ
MAINTENANCE INTERVALS
ROTOR NUT
Retighten
EXHAUST PIPE, SILENCER,
PROTECTOR
Inspect and retighten
Clean
Replace* Whichever comes first
*SPARK ARRESTER
Clean
(Every
six
months)
CRANK
Inspect and clean
CARBURETOR
Inspect, adjust and clean
AIR INDUCTION SYSTEM
Inspect and clean
SPARK PLUG
Inspect and clean
Replace
DRIVE CHAINUse chain lube
Chain slack:
48 ~ 58 mm (1.9 ~ 2.3 in) Lubricate, slack, alignment
Replace
COOLING SYSTEM
Check coolant level and leakage
Check radiator cap operation
Replace coolantEvery two years
Inspect hoses
OUTSIDE NUTS AND BOLTS Refer to “STARTING AND
BREAK-IN” section in the
CHAPTER 1. Retighten
AIR FILTER
Clean and lubricate Use foam air-filter oil or
equivalent oil
Replace
OIL FILTER
Replace
OIL STRAINER (frame)
Clean
FRAME
Clean and inspect
FUEL TANK, COCK
Clean and inspect
BRAKES
Adjust lever position and pedal height
Lubricate pivot point
Check brake disc surface
Check fluid level and leakage
Retighten brake disc bolts, caliper bolts,
master cylinder bolts and union bolts
Replace pads
Replace brake fluid Every one yearItemAfter
break-inEvery
race
Every third
(or
500 km)Every fifth
(or
1,000 km)As
requiredRemarks
1
2
3
4
5
6
7

3 - 16
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-21 ~ 29
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-49
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-39 ~ 47
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-29 ~ 31
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-31 ~ 33
Brakes Check the play of front brake and effect of front and rear brake. P.3-65 ~ 77
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-79 ~ 83
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-99 ~ 101
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-101 ~ 103
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-85 ~ 97
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or when
the front forks travel up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-7 ~ 11
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-77
Lubrication Check for smooth operation. Lubricate if necessary. P.3-105
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-59
Lead connectorsCheck that the AC magneto, CDI unit, and ignition coil are
connected tightly.P.1-9
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 40

3 - 65
INSP
ADJ
EC360000
CHASSIS
EC361012BRAKE SYSTEM AIR BLEEDING
WARNING
Bleed the brake system if:
The system has been disassem-
bled.
A brake hose has been loosened
or removed.
The brake fluid is very low.
The brake operation is faulty.
A dangerous loss of braking per-
formance may occur if the brake
system is not properly bled.
1. Remove:
Brake master cylinder cap
Diaphragm
Reservoir float (front brake)
Protector (rear brake)
2. Bleed:
Brake fluid
ÈFront
ÉRear
Air bleeding steps:
a. Add proper brake fluid to the
reservoir.
b. Install the diaphragm. Be care-
ful not to spill any fluid or allow
the reservoir to overflow.
c. Connect the clear plastic tube
2 tightly to the caliper bleed
screw
1.
d. Place the other end of the tube
into a container.
e. Slowly apply the brake lever or
pedal several times.
f. Pull the lever in or push down
on the pedal. Hold the lever or
pedal in position.
g. Loosen the bleed screw and
allow the lever or pedal to
travel towards its limit.
h. Tighten the bleed screw when
the lever or pedal limit has
been reached; then release the
lever or pedal.
T R..
Bleed screw:
6 Nm
(0.6 m  kg, 4.3 ft  lb)
i. Repeat steps (e) to (h) until of
the air bubbles have been
removed from the system.
È
É
CHASSIS
PURGE D’AIR DU CIRCUIT DE
FREINAGE
AVERTISSEMENT
Purger l’air du circuit de freinage si:
Le circuit a été démonté.
Une durit de frein a été desserrée ou
déposée.
Le niveau du liquide de frein est très
bas.
Le frein fonctionne mal.
Si le circuit de freinage n’est pas cor-
rectement purgé, il peut s’ensuivre
une dangereuse perte d’efficacité du
freinage.
1. Déposer:
Couvercle de maître-cylindre de
frein
Diaphragme
Flotteur du réservoir (frein avant)
Protection (frein arrière)
2. Purger:
Liquide de frein
È
Avant
É
Arrière
Étapes de la purge de l’air:
a. Ajouter le liquide de frein adéquat
dans le réservoir.
b. Poser le diaphragme. Veiller à ne
pas renverser de liquide et à ne pas
faire déborder le réservoir.
c. Connecter hermétiquement le
tuyau en plastique transparent 2 à
la vis de purge 1 de l’étrier.
d. Placer l’autre extrémité du tuyau
dans un récipient.
e. Actionner lentement et plusieurs
fois le levier ou la pédale de frein.
f. Tirer le levier ou enfoncer la
pédale. Maintenir le levier ou la
pédale dans leur position respec-
tive.
g. Desserrer la vis de purge et laisser
le levier ou la pédale parvenir en
fin de course.
h. Serrer la vis de purge quand le
levier ou la pédale sont arrivés en
fin de course, puis relâcher le
levier ou la pédale.
T R..
Vis de purge:
6 Nm
(0,6 m  kg, 4,3 ft  lb)
i. Répéter les opérations (e) à (h)
jusqu’à l’élimination totale des
bulles d’air du circuit.
CHASSIS
CHASSIS

3 - 67
INSP
ADJ
3. Install:
Protector (rear brake)
Reservoir float (front brake)
Diaphragm
Brake master cylinder cap
EC362040FRONT BRAKE ADJUSTMENT
1. Check:
Brake lever position
a
2. Remove:
Brake lever cover
3. Adjust:
Brake lever position
4. Install:
Brake lever cover
NOTE:If bleeding is difficult, it may be
necessary to let the brake fluid sys-
tem stabilize for a few hours.
Repeat the bleeding procedure
when the tiny bubbles in the sys-
tem have disappeared.
j. Add brake fluid to the level line
on the reservoir.
WARNING
Check the operation of the brake
after bleeding the brake system.
Brake lever position a:
Standard
positionExtent of
adjustment
95 mm (3.74 in)76 ~ 97 mm
(2.99 ~ 3.82 in)
Brake lever position adjust-
ment steps:
Loosen the locknut
1.
Turn the adjusting bolt
2 until
the lever position
a is within
specified position.
Tighten the locknut.
T R..
Locknut:
5 Nm
(0.5 m  kg, 3.6 ft  lb)
CAUTION:
Be sure to tighten the locknut,
as it will cause poor brake per-
formance.
3. Monter:
Protection (frein arrière)
Flotteur du réservoir (frein avant)
Diaphragme
Couvercle de maître-cylindre de
frein
REGLAGE DU FREIN AVANT
1. Contrôler:
Position du levier de frein a
2. Déposer:
Couvercle du levier de frein
3. Régler:
Position du levier de frein
4. Monter:
Couvercle du levier de frein
N.B.:
Si la purge est difficile, il peut être
nécessaire de laisser le circuit du
liquide de frein se stabiliser pendant
quelques heures. Répéter la procédure
de purge quand les petites bulles d’air
ont disparu du circuit.
j. Ajouter du liquide de frein jusqu’à
la ligne de niveau du réservoir.
AVERTISSEMENT
Vérifier le fonctionnement du frein
après avoir purgé le circuit de frei-
nage.
Position du levier de frein
a:
Position standard Plage de réglage
95 mm (3,74 in)76 à 97 mm
(2,99 à 3,82 in)
Etapes du réglage de la position du
levier de frein:
Desserrer le contre-écrou 1.
Faire tourner le boulon de réglage
2 jusqu’à ce que la position du
levier a soit conforme aux spéci-
fications.
Serrer le contre-écrou.
T R..
Contre-écrou:
5 Nm
(0,5 m  kg, 3,6 ft  lb)
ATTENTION:
Veiller à bien serrer le contre-
écrou pour éviter toute baisse
d’efficacité du freinage.
CHASSIS
CHASSIS