brake YAMAHA WR 250F 2006 User Guide

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

3 - 69
INSP
ADJ
EC364002REAR BRAKE ADJUSTMENT
1. Check:
Brake pedal height
a
Out of specification
→ Adjust.
2. Adjust:
Brake pedal height
Brake pedal height a:
5 mm (0.20 in)
Pedal height adjustment steps:
Loosen the locknut
1.
Turn the adjusting nut
2 until
the pedal height
a is within
specified height.
Tighten the locknut.
WARNING
Adjust the pedal height
between the maximum È and
the minimum É as shown. (In
this adjustment, the bolt 3
end b should protrude out of
the threaded portion 4 but
not be less than 2 mm
(0.08 in) c away from the
brake pedal 5).
After the pedal height adjust-
ment, make sure that the rear
brake does not drag.
ÈÉ
FRONT BRAKE PAD INSPECTION
AND REPLACEMENT
1. Inspect:
Brake pad thickness
a
Out of specification
→
Replace as a set.
Brake pad thickness:
4.4 mm (0.17 in)
:
1.0 mm (0.04 in)
2. Replace:
Brake pad
Brake pad replacement steps:
Remove the pad pin plug
1.
REGLAGE DU FREIN ARRIERE
1. Contrôler:
Hauteur de la pédale de frein a
Hors spécifications → Ajuster.
2. Régler:
Hauteur de la pédale de frein
Hauteur de la pédale de
frein a:
5 mm (0,20 in)
Étapes du réglage de la hauteur de
la pédale de frein:
Desserrer le contre-écrou 1.
Faire tourner l’écrou de réglage 2
jusqu’à ce que la hauteur de la
pédale a soit conforme aux spéci-
fications.
Serrer le contre-écrou.
AVERTISSEMENT
Régler la hauteur de la pédale
entre le maximum È et le mini-
mum É comme illustré. (Dans ce
réglage, l’extrémité b du boulon
3 doit dépasser de la partie file-
tée 4 mais ne doit pas être dis-
tante de moins de 2 mm (0,08 in)
c de la pédale de frein 5).
Après le réglage de la hauteur de
la pédale de frein, contrôler que
le frein arrière ne frotte pas.
CONTROLE ET REMPLACEMENT
DES PLAQUETTES DE FREIN
AVANT
1. Contrôler:
Epaisseur de la plaquette de frein
a
Hors spécifications → Remplacer
l’ensemble.
Epaisseur de la plaquette
de frein:
4,4 mm (0,17 in)
:
1,0 mm (0,04 in)
2. Remplacer:
Plaquette de frein
Etapes du remplacement des pla-
quettes de frein:
Déposer le bouchon de goupille de
plaquette 1.
CHASSIS
CHASSIS

3 - 71
INSP
ADJ
Loosen the pad pin
2.
Remove the brake caliper
3
from the front fork.
Remove the pad pin and brake
pads
4.
Connect the transparent hose
5 to the bleed screw
6 and
place the suitable container
under its end.
Loosen the bleed screw and
push the brake caliper piston in.
CAUTION:
Do not reuse the drained brake
fluid.
Tighten the bleed screw.
T R..
Bleed screw:
6 Nm
(0.6 m  kg, 4.3 ft  lb)
Install the brake pads
7 and
pad pin.
NOTE:Install the brake pads with their
projections
a into the brake
caliper recesses
b.
Temporarily tighten the pad pin
at this point.
Install the brake caliper
8 and
tighten the pad pin
9.
T R..
Bolt (brake caliper):
23 Nm
(2.3 m  kg, 17 ft  lb)
Pad pin:
18 Nm
(1.8 m  kg, 13 ft  lb)
Install the pad pin plug
0.
T R..
Pad pin plug:
3 Nm
(0.3 m  kg, 2.2 ft  lb)
3. Inspect:
Brake fluid level
Refer to “BRAKE FLUID
LEVEL INSPECTION” section.Desserrer la goupille de plaquette
2.
Déposer l’étrier de frein 3 de la
fourche.
Déposer la goupille de plaquette et
les plaquettes de frein 4.
Raccorder le tuyau transparent 5 à
la vis de purge 6 et placer un réci-
pient adéquat sous son extrémité.
Desserrer la vis de purge et enfon-
cer le piston de l’étrier de frein.
ATTENTION:
Ne pas réutiliser le liquide de frein
purgé.
Resserrer la vis de purge.
T R..
Vis de purge:
6 Nm
(0,6 m  kg, 4,3 ft  lb)
Monter les plaquettes de frein 7 et
la goupille de plaquette.
N.B.:
Monter les plaquettes de frein en
insérant leurs ergots a dans les
gorges des étriers de freins b.
A ce stade, serrer provisoirement la
goupille de plaquette.
Monter l’étrier de frein 8 et serrer
la goupille de plaquette 9.
T R..
Boulon (étrier de frein):
23 Nm
(2,3 m  kg, 17 ft  lb)
Goupille de plaquette:
18 Nm
(1,8 m  kg, 13 ft  lb)
Monter le bouchon de goupille de
plaquette 0.
T R..
Bouchon de goupille de
plaquette:
3 Nm
(0,3 m  kg, 2,2 ft  lb)
3. Contrôler:
Niveau du liquide de frein
Se reporter à la section “CON-
TROLE DU NIVEAU DU
LIQUIDE DE FREIN”.
CHASSIS
CHASSIS

3 - 73
INSP
ADJ
4. Check:
Brake lever operation
A softy or spongy feeling
→
Bleed brake system.
Refer to “BRAKE SYSTEM
AIR BLEEDING” section.
REAR BRAKE PAD INSPECTION
AND REPLACEMENT
1. Inspect:
Brake pad thickness
a
Out of specification
→
Replace as a set.
Brake pad thickness:
6.4 mm (0.25 in)
:
1.0 mm (0.04 in)
2. Replace:
Brake pad
Brake pad replacement steps:
Remove the protector
1 and
pad pin plug
2.
Loosen the pad pin
3.
Remove the rear wheel
4 and
brake caliper
5.
Refer to “FRONT WHEEL AND
REAR WHEEL” section in the
CHAPTER 5.
Remove the pad pin
6 and
brake pads
7.
Connect the transparent hose
8 to the bleed screw
9 and
place the suitable container
under its end.
Loosen the bleed screw and
push the brake caliper piston in.
CAUTION:
Do not reuse the drained brake
fluid.
Tighten the bleed screw.
T R..
Bleed screw:
6 Nm
(0.6 m  kg, 4.3 ft  lb)
4. Contrôler:
Fonctionnement du levier de frein
Sensation de mollesse → Purger
le circuit de freinage.
Se reporter à la section “PURGE
D’AIR DU CIRCUIT DE FREI-
NAGE”.
CONTROLE ET REMPLACEMENT
DES PLAQUETTES DE FREIN
ARRIERE
1. Contrôler:
Epaisseur des plaquettes de freins
a
Hors spécifications → Remplacer
l’ensemble.
Epaisseur de la plaquette
de frein:
6,4 mm (0,25 in)
:
1,0 mm (0,04 in)
2. Remplacer:
Plaquette de frein
Etapes du remplacement des pla-
quettes de frein:
Déposer la protection 1 et le bou-
chon de goupille de plaquette 2.
Desserrer la goupille de plaquette
3.
Déposer la roue arrière 4 et
l’étrier de frein 5.
Se reporter à la section “ROUE
AVANT ET ROUE ARRIERE” au
CHAPITRE 5.
Déposer la goupille de plaquette 6
et les plaquettes de frein 7.
Raccorder le tuyau transparent 8 à
la vis de purge 9 et placer un réci-
pient adéquat sous son extrémité.
Desserrer la vis de purge et enfon-
cer le piston de l’étrier de frein.
ATTENTION:
Ne pas réutiliser le liquide de frein
purgé.
Resserrer la vis de purge.
T R..
Vis de purge:
6 Nm
(0,6 m  kg, 4,3 ft  lb)
CHASSIS
CHASSIS

3 - 75
INSP
ADJ
3. Inspect:
Brake fluid level
Refer to “BRAKE FLUID
LEVEL INSPECTION” section.
4. Check:
Brake pedal operation
A softy or spongy feeling
→
Bleed brake system.
Refer to “BRAKE SYSTEM
AIR BLEEDING” section. Install the brake pad
0 and pad
pin
A.
NOTE:Install the brake pads with their
projections
a into the brake
caliper recesses
b.
Temporarily tighten the pad pin
at this point.
Install the brake caliper
B and
rear wheel
C.
Refer to “FRONT WHEEL AND
REAR WHEEL” section in the
CHAPTER 5.
Tighten the pad pin
D.
T R..
Pad pin:
18 Nm
(1.8 m  kg, 13 ft  lb)
Install the pad pin plug
E and
protector
F.
T R..
Pad pin plug:
3 Nm
(0.3 m  kg, 2.2 ft  lb)
Bolt (protector):
7 Nm
(0.7 m  kg, 5.1 ft  lb)
EC36b000REAR BRAKE PAD INSULATOR
INSPECTION
1. Remove:
Brake pad
Refer to “REAR BRAKE PAD
INSPECTION AND RE-
PLACEMENT” section.
2. Inspect:
Rear brake pad insulator
1
Damage
→ Replace.
3. Contrôler:
Niveau du liquide de frein
Se reporter à la section “CON-
TROLE DU NIVEAU DU
LIQUIDE DE FREIN”.
4. Contrôler:
Fonctionnement de la pédale de
frein
Sensation de mollesse → Purger
le circuit de freinage.
Se reporter à la section “PURGE
D’AIR DU CIRCUIT DE FREI-
NAGE”. Monter les plaquettes de frein 0 et
la goupille de plaquette A.
N.B.:
Monter les plaquettes de frein en
insérant leurs ergots a dans les
gorges des étriers de freins b.
A ce stade, serrer provisoirement la
goupille de plaquette.
Monter l’étrier de frein B et la
roue arrière C.
Se reporter à la section “ROUE
AVANT ET ROUE ARRIERE” au
CHAPITRE 5.
Serrer la goupille de plaquette D.
T R..
Goupille de plaquette:
18 Nm
(1,8 m  kg, 13 ft  lb)
Monter le bouchon de plaquette de
frein E et la protection F.
T R..
Bouchon de goupille de
plaquette:
3 Nm
(0,3 m  kg, 2,2 ft  lb)
Boulon (protection):
7 Nm
(0,7 m  kg, 5,1 ft  lb)
CONTROLE DE L’ISOLANT DE
PLAQUETTE DE FREIN ARRIERE
1. Déposer:
Plaquette de frein
Se reporter à la section “CON-
TROLE ET REMPLACEMENT
DES PLAQUETTES DE FREIN
ARRIERE”.
2. Contrôler:
Isolation de plaquette de frein
arrière 1
Endommagement → Remplacer.
CHASSIS
CHASSIS