engine YAMAHA WR 250F 2007 Owners Manual

6 - 61
CHASFRONT FORK
EC550000
FRONT FORK
Extent of removal:
1 Front fork removal
Extent of removal Order Part name Q’ty Remarks
FRONT FORK REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Front wheel Refer to “FRONT WHEEL AND REAR WHEEL”
section.
Front brake caliper Refer to “FRONT BRAKE AND REAR BRAKE”
section.
Headlight
Handlebar Refer to “HANDLEBAR” section.
1 Protector 1
2 Pinch bolt (upper bracket) 2 Only loosening.
3 Cap bolt 1 Loosen when disassembling the front fork.
4 Pinch bolt (lower bracket) 2 Only loosening.
5 Front fork 1
1

6 - 91
CHASHANDLEBAR
EC5B0000
HANDLEBAR
Extent of removal:
1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removalHANDLEBAR REMOVAL
Headlight
1 Hot starter cable 1 Disconnect at the lever side.
2 Hot starter lever holder 1
3 Clutch cable 1 Disconnect at the lever side.
4 Clutch lever holder 1 Disconnect the clutch switch lead.
5 Engine stop switch 1 Disconnect the engine stop switch lead.
6 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
7 Start switch 1 Disconnect the start switch lead.
8 Throttle cable cap 1
9 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
10 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
11 Right grip 1 Refer to “REMOVAL POINTS”.
12 Tube guide 1
13 Left grip 1 Refer to “REMOVAL POINTS”.
14 Handlebar upper holder 2
15 Handlebar 1
16 Handlebar lower holder 2
1

6 - 103
CHAS
11. Install:
•Engine stop switch
1
•Clutch lever holder
2
•Bolt (clutch lever holder)
3
•Hot starter lever holder
4
•Bolt
(hot starter lever holder)
5
•Clamp
6
NOTE:•The engine stop switch, clutch
lever holder and clamp should be
installed according to the dimen-
sions shown.
•Pass the engine stop switch lead in
the middle of the clutch lever
holder.
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
T R..4 Nm (0.4 m · kg, 2.9 ft · lb)
12. Install:
•Clutch cable
1
•Hot starter cable
2
NOTE:Apply the lithium soap base grease
on the clutch cable end and hot
starter cable end.
13. Adjust:
•Clutch lever free play
Refer to “CLUTCH ADJUST-
MENT” section in the CHAP-
TER 3.
•Hot starter lever free play
Refer to “HOT STARTER
LEVER ADJUSTMENT” sec-
tion in the CHAPTER 3.
11. Monter:
Coupe-circuit du moteur 1
Support du levier d’embrayage
2
Boulon (support du levier
d’embrayage) 3
Support du levier de démarrage à
chaud 4
Boulon
(support du levier de démarrage à
chaud) 5
Collier 6
N.B.:
Monter le coupe-circuit du moteur, le
support du levier d’embrayage et le
collier en respectant les dimensions
indiquées.
Faire passer le fil du coupe-circuit du
moteur au milieu du support du levier
d’embrayage.
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
T R..4 Nm (0,4 m · kg, 2,9 ft · lb)
12. Monter:
Câble d’embrayage 1
Câble de démarrage à chaud 2
N.B.:
Appliquer de la graisse à savon de lithium
sur les extrémités du câble d’embrayage
et du câble de démarrage à chaud.
13. Régler:
Jeu du levier d’embrayage
Se reporter à la section “REGLAGE
DE L’EMBRAYAGE” au CHAPI-
TRE 3.
Jeu du levier de démarrage à
chaud
Se reporter à la section
“REGLAGE DU LEVIER DE
DEMARRAGE A CHAUD” au
CHAPITRE 3.
HANDLEBAR
GUIDON

6 - 105
CHASSTEERING
EC560000
STEERING
Extent of removal:
1 Lower bracket removal
2 Bearing removal
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Headlight
Handlebar Refer to “HANDLEBAR” section.
Front brake hose guide
Front fender
1 Multi-function display 1
2 Multi-function display bracket 1
3 Main switch 1 Disconnect the main switch lead.
4 Steering stem nut 1
5 Front fork 2 Refer to “FRONT FORK” section.
6 Upper bracket 1
7 Steering ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
8 Lower bracket 1
12

6 - 121
CHASSWINGARM
EC570000
SWINGARM
Extent of removal:
1 Swingarm removal
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Brake hose holder
Refer to “FRONT BRAKE AND REAR BRAKE”
section.
Rear brake caliper
Bolt (brake pedal) Shift the brake pedal backward.
Drive chain
1 Drive chain support 1
2 Lower chain tensioner 1
3 Bolt (rear shock absorber-relay arm) 1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1
1

6 - 141
CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
Extent of removal:
1 Rear shock absorber removal
2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER REMOVAL
WARNING
Support the machine securely so there is nodanger of it falling over. Preparation for removal Hold the machine by placing the suitable
stand under the engine.
Seat and side covers Refer to “SEAT, FUEL TANK AND SIDE COVERS”
section in the CHAPTER 3.
Silencer Refer to “EXHAUST PIPE AND SILENCER” section
in the CHAPTER 3.
Drain the coolant. Refer to “COOLANT REPLACEMENT” section in the
CHAPTER 3.
Catch tank breather hose Disconnect at the catch tank side.
Catch tank hose Disconnect at the catch tank side.
Air induction hose (air cut-off valve-air filter
case)Disconnect at the air filter case side.
Cylinder head breather hose Disconnect at the air filter case side.
Battery Refer to “BATTERY INSPECTION AND
CHARGING” section in the CHAPTER 3.
Disconnect the starter relay coupler.
Starter motor lead Disconnect at the starter relay side.

7 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
NOTE:This section is intended for those who have basic knowledge and skill concerning the servicing of Yamaha motorcycles
(e.g., Yamaha dealers, service engineers, etc.) Those who have little knowledge and skill concerning servicing are
requested not to undertake inspection, adjustment, disassembly, or reassembly only by reference to this manual. It may
lead to servicing trouble and mechanical damage.
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000ELECTRICAL COMPONENTS
1Headlight
2Multi-function display
3Engine stop switch
4Clutch switch
5Diode
6Starter relay diode7Throttle position sensor
8Starter relay
9Fuse
0Starting circuit cut-off relay
ACDI unit
BTaillightCNeutral switch
DStarter motor
EAC magneto
FRectifier/regulator
GIgnition coil
HSpark plugIStart switch
JMain switch
KSpeed sensor
LBattery

7 - 3
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC612000WIRING DIAGRAM
1Headlight
2Multi-function display
3Engine stop switch
4Clutch switch
5Diode
6Starter relay diode
7Throttle position sensor
8Starter relay
9Fuse
0Starting circuit cut-off relay
ACDI unitBTaillight
CNeutral switch
DStarter motor
EAC magneto
FRectifier/regulator
GIgnition coil
HSpark plug
IStart switch
JMain switch
KSpeed sensor
LBatteryCOLOR CODE
B ...................... Black
Br ..................... Brown
Ch .................... Chocolate
Dg .................... Dark green
G...................... Green
Gy .................... Gray
L ...................... Blue
O...................... Orange
R ...................... RedSb .................... Sky blue
W ..................... White
Y ...................... Yellow
B/L ................... Black/Blue
B/W .................. Black/White
L/B ................... Blue/Black
L/R ................... Blue/Red
L/Y ................... Blue/Yellow
L/W .................. Blue/White
R/B................... Red/Black
R/W.................. Red/White

7 - 5
–+ELECIGNITION SYSTEM
EC620000
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 “FUSE INSPECTION” section in the CHAPTER 3.
*2 marked: Refer to “BATTERY INSPECTION AND CHARGING” section in the CHAPTER 3.
*3 marked: Only when the ignition checker is used.
NOTE:•Remove the following parts before inspection.
1) Seat
2) Fuel tank
•Use the following special tools in this inspection.
*1 Check fuse.Replace fuse and check
wire harness.
*2 Check battery. Recharge or replace.
Spark gap test*3 Clean or replace spark
plug.
Check entire ignition system for
connection.
(couplers, leads and ignition coil)Repair or replace.
Check engine stop switch. Replace.
Check main switch.Replace.
Check ignition coil. Primary coil Replace.
Secondary coil Replace.
Check AC magneto. Pickup coil Replace.
Check neutral switch. Repair or replace.
Replace CDI unit.
Dynamic spark tester:
YM-34487
Ignition checker:
90890-06754
Pocket tester:
YU-3112-C/
90890-03112
No good
OK
No good
OK
Spark
No spark
No good
OK
No good
OK
No good
OK
No good
OKNo good
No good
OK
No good
OK

7 - 11
–+ELECIGNITION 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 checker
2) as
shown.
•Ignition coil
3
•Spark plug
4
ÈFor USA and CDN
ÉExcept 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)
Minimum spark gap:
6.0 mm (0.24 in)
È
É
COUPLERS, LEADS AND
IGNITION COIL CONNECTION
INSPECTION
1. Check:
•Couplers and leads connec-
tion
Rust/dust/looseness/short-cir-
cuit
→ 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.
ENGINE STOP SWITCH
INSPECTION
1. Inspect:
•Engine stop switch conduct
No continuity while being pushed
→
Replace.
Continuity while being freed
→
Replace.Tester (+) lead →
Black lead 1

Tester (–) lead →
Black lead 2

B
1
B
2
Tester
selector
position
PUSH IN
Ω
×
1
FREE
TEST DE LA LONGUEUR
D’ETINCELLE
1. Déconnecter la bobine d’allumage
de la bougie.
2. Déposer le capuchon de la bobine
d’allumage.
3. Connecter le testeur dynamique
d’étincelle 1 (contrôleur d’allu-
mage 2) comme indiqué.
Bobine d’allumage 3
Bougie 4
È
USA et CDN
É
Sauf USA et CDN
4. Actionner le kick.
5. Contrôler la longueur d’étincelle
d’allumage.
6. Démarrer le moteur et augmenter la
longueur d’étincelle jusqu’à ce
qu’un raté se produise. (uniquement
USA et CDN)
Longueur d’étincelle
minimum:
6,0 mm (0,24 in)
CONTROLE DES CONNEXIONS
DES FICHES RAPIDES, DES FILS
ET DE LA BOBINE D’ALLUMAGE
1. Vérifier:
Connexion des coupleurs et des
fils
Rouille/poussière/jeu/court-cir-
cuit → Réparer ou remplacer.
Bobine d’allumage et bougie en
place
Appuyer sur la bobine d’allu-
mage jusqu’à ce qu’elle soit en
contact étroit avec le trou de bou-
gie du couvre-culasse.
CONTROLE DU COUPE-CIRCUIT
DU MOTEUR
1. Contrôler:
Continuité du coupe-circuit du
moteur
Pas de continuité lorsque enfoncé →
Remplacer.
Continuité lorsque relâché → Rempla-
cer.Fil (+) du multimètre → fil noir 1
Fil (–) du multimètre → fil noir 2
B
1 B
2 Position du
sélecteur du
multimètre
ENFONCE
Ω × 1
RELACHE
SYSTEME D’ALLUMAGE