ignition YAMAHA WR 250F 2003 User Guide

3 - 129
INSP
ADJ
2. Check:
Continuity
2Reserve fuse
Checking steps:
Remove the fuse
1.
Connect the pocket tester to the
fuse and check the continuity.
NOTE:Set the pocket tester selector to
“
Ω
× 1”.
Pocket tester:
YU-3112-C/
90890-03112
If the pocket tester indicates
“
∞”, replace the fuse. 2
1
3. Replace:
Blown fuse
WARNING
Never use a fuse with an amper-
age rating other than that speci-
fied. Improvising or using a fuse
with the wrong amperage rating
may cause extensive damage to
the electrical system, cause the
starting and ignition systems to
malfunction and could possibly
cause a fire.
4. Install:
Fuse cover
Seat Replacement steps:
Set the main switch to “OFF”.
Install a new fuse of the correct
amperage.
Set on the switches to verify if
the electrical circuit is opera-
tional.
If the fuse immediately blows
again, check the electrical cir-
cuit.
ItemsAmperage
ratingQ’ty
Main fuse 10 A 1
2. Contrôler:
Continuité
2
Fusible de rechange
Etapes de la vérification:
Depose du fusible 1
.
Connecter le multimètre au fusible
et contrôler la continuité du circuit.
N.B.:
Régler le sélecteur du multimètre sur
“Ω × 1”.
Multimètre
YU-3112-C/
90890-03112
Si le multimètre indique “∞”, rem-
placer le fusible.
3. Remplacer:
Fusible grillé
AVERTISSEMENT
Ne jamais utiliser un fusible d’ampé-
rage différent de celui spécifié. Toute
improvisation ou la mise en place d’un
fusible d’un ampérage incorrect ris-
que de gravement endommager le cir-
cuit électrique, de provoquer un
mauvais fonctionnement du système
de démarrage et d’allumage et pour-
rait même être à l’origine d’un incen-
die.
4. Monter:
Couvercle de fusibles
Selle Etapes de remplacement:
Placer le contacteur à clé sur
“OFF”.
Monter un nouveau fusible
d’ampérage correct.
Mettre les contacteurs en circuit
afin de vérifier si le circuit électri-
que fonctionne.
Si le fusible grille immédiatement,
contrôler le circuit électrique.
Description IntensitéQté
Fusible principal 10 A 1
ELECTRICAL
PARTIE ELECTRIQUE

4 - 207
ENGENGINE REMOVAL
Extent of removal:
1 Engine removal
Extent of removal Order Part name Q’ty Remarks
Ignition coil
Disconnect the AC magneto lead.
Starter motor lead Disconnect at the starter motor side.
Negative battery lead Disconnect at the engine side.
Right engine guard
1 Neutral switch 1
2 Drive chain sprocket cover 1
3 Nut (drive sprocket) 1
Refer to “REMOVAL POINTS”. 4 Lock washer 1
5 Drive sprocket 1
6 Clip 1
7 Bolt (brake pedal) 1
8 Brake pedal 1
9 Upper engine bracket 2
10 Lower engine bracket 2
11 Engine mounting bolt 3
12 Pivot shaft 1
Refer to “REMOVAL POINTS”.
13 Engine 1
1

6 - 1
–+ELECELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC600000
ELECTRICAL
EC610000
ELECTRICAL COMPONENTS AND WIRING DIAGRAM
EC611000ELECTRICAL COMPONENTS
1Headlight
2Engine stop switch
3Clutch switch
4Diode
5Starter relay diode
6Throttle position sensor
7Starter relay
8Fuse
9Starting circuit cut-off relay
0TaillightANeutral switch
BStarter motor
CAC magneto
DRectifier/regulator
EIgnition coil
FSpark plug
GStart switch
HLight switch
IMain switch
JCDI unit
KBatteryCOLOR CODE
B ...................... Black
Br ..................... Brown
Gy .................... Gray
L ...................... Blue
O...................... Orange
R ...................... Red
Sb .................... Sky blue
W ..................... White
Y ...................... YellowB/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
EC612000WIRING DIAGRAM
1 2345
678
90
A
B CDEFGH
I
J
K
WR
WR
R
BR/BBr
R
BR/BBr
RW
L/RL/BBB
SbL/W
WY
YW
L/YBBB
WY
RYW
R
LY
B
YLB/L
B
B
ON
OFF
10A
BB
OFF
ON
OFF
STARTSTART
R-BrL/W
BLY
YLB-LB
B
BrL/W
BrL/W
L/B-LB
YL
B
L-B
-Sb
B/WBBB
W/RB/W
R/BGyBrL/W
ON
STOP
OB
LYSbB/L
W RBrB/W
L/BGyWR/BO B
L Y SbB/L
B O
L/YSbL/R
R W
Y W
Y W
Y B
B
L
L L
L B
B
B
RRR/B
B Br B
B B B B
L/W
R
R
R R B
R
BrBr
L/W L/W
Br B
L/B
L/B
L/R

Br
R/B
L/B L/W
B/W
W W/RW
RO
L
Y
B/L
O

B
L
Y
B/LSbB/W
B
L/R L/Y L/Y
B
SbSb
BGy
C
HD
BI
5
9
G3 4
A 2J
EF
6 78
1
0K

6 - 3
–+ELECMAP-CONTROLLED CDI UNIT
MAP-CONTROLLED CDI UNIT
A map-controlled, CDI ignition system is used in the WR250F.
The microcomputer in the CDI unit detects the engine speed and throttle position, thus determining the optimum ignition
timing through the entire operating range. In this way, quick throttle response can be achieved according to various riding
conditions.






Function of Component






Principal of 3-Dimensional Control
Conventionally, ignition timing was controlled only by
engine revolutions (2-dimensional control).
However, ignition timing needs advancement also by
engine load. Thus, accurate ignition timing can be deter-
mined by adding throttle opening to determine ignition
timing (3-dimensional control).
3-D Image Map of Ignition Timing
(different from actual characteristics)
Component Function
Throttle position sensor Detects throttle valve opening and inputs it into the computer in the CDI unit as a
throttle opening signal.
Pickup coil Detects signal rotor revolutions and inputs them into the computer in the CDI unit as
engine revolution signals.
CDI unit The signals of the throttle position sensor and pickup coil sensor are analyzed by
the computer in the CDI unit, which then adjusts ignition timing for the operation
requirements.
CDI unit
Throttle position sensor
Pickup coil AC magneto rotorIgnition coil
Revolutions
Ignition timing
Throttle opening

6 - 8
–+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

6 - 13
–+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 D’ALLUMAGE
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 (testeur d’allumage
2) comme indiqué.
Bobine d’allumage 3
Bougie 4
È
USA et CDN
É
Excepté 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 RACCORDS, FILS ET BOBINE
D’ALLUMAGE
1. Contrôler:
Connexion de coupleurs et fils
Rouille/poussière/jeu/court-cir-
cuit → Réparer ou remplacer.
Bobine d’allumage et bougie tel-
les quelles
Insérer la bobine d’allumage
jusqu’à ce qu’elle touche le trou
de bougie dans le couvercle de la
culasse.
CONTROLE DU COUPE-CIRCUIT
DU MOTEUR
1. Contrôler:
Continuité du coupe-circuit du
moteur
Pas de continuité lorsqu’enfoncé →
Remplacer.
Continuité lorsque relâché → Rempla-
cer.Fil (+) de multimètre → Fil noir 1
Fil (–) de multimètre → Fil noir 2
B
1 B
2 Position de
sélecteur du
multimètre
ENFONCE
Ω × 1
RELACHE
SYSTEME D’ALLUMAGE

6 - 15
–+ELECIGNITION SYSTEM
2. Inspect:
Rubber part
a
Tears/damage
→ Replace.
a
MAIN SWITCH INSPECTION
1. Inspect:
Main switch conduct
Continuous while the main switch is
moved to “OFF”
→ Replace.
Not continuous while the main switch
is moved to “ON”
→ Replace. Tester (+) lead →
Red lead 1

Tester (–) lead →
Brown lead 2

R
1
Br
2
Tester
selector
position
ON
Ω
×
1
OFF
2. Inspect:
Main switch indicator light
Use 12 V battery.
Indicator light does not come on
→
Replace.Battery (+) lead →

Red/Black lead 1
Battery (–) lead →
Black lead 2

3. Inspect:
Rubber part
a
Tears/damage
→ Replace.
a
2. Contrôler:
Pièce en caoutchouc a
Fissures/dommage → Remplacer.
CONTROLE DU COMMUTATEUR
PRINCIPAL
1. Contrôler:
Conducteur du commutateur prin-
cipal
Continuité lorsque le commutateur est
mis en position “OFF” → Remplacer.
Discontinuité lorsque le commutateur est
mis en position “ON” → Remplacer. Fil (+) de multimètre → Fil rouge 1
Fil (–) de multimètre → Fil brun 2
R
1 Br
2 Position de
sélecteur du
multimètre
ON
Ω × 1
OFF
2. Contrôler:
Témoin du commutateur princi-
pal
Utiliser une batterie de 12 V.
Le témoin ne s’allume pas → Rempla-
cer. Câble (+) de la batterie →
Câble rouge/noir 1
Câble (–) de la batterie →
Câble noir 2
3. Contrôler:
Pièce en caoutchouc a
Fissures/dommage → Remplacer.
SYSTEME D’ALLUMAGE

6 - 17
–+ELECIGNITION SYSTEM
EC626002IGNITION COIL INSPECTION
1. Remove the ignition coil cap.
2. Inspect:
Primary coil resistance
Out of specification
→
Replace.
Tester (+) lead →
Orange lead 1

Tester (–) lead →
Black lead 2

Primary coil
resistanceTester
selector
position
0.08 ~ 0.10 Ω

at 20 °C (68 °F)Ω
×
1
3. Inspect:
Secondary coil resistance
Out of specification
→
Replace.
Tester (+) lead →
Orange lead 1

Tester (–) lead →

Spark plug terminal 2
Secondary
coil resistanceTester
selector
position
4.6 ~ 6.8 kΩ
at
20 °C (68 °F)kΩ
×
1
4. Inspect:
Sealed portion of ignition coil
a
Spark plug terminal pin
b
Threaded portion of spark plug
c
Wear
→ Replace.
CONTROLE DE LA BOBINE
D’ALLUMAGE
1. Déposer la bobine d’allumage.
2. Contrôler:
Résistance de bobine primaire
Hors spécification → Remplacer.
Fil (+) de multimètre →
Fil orange 1
Fil (–) de multimètre → Fil noir 2
Résistance de
bobine primairePosition de
sélecteur du
multimètre
0,08 à 0,10 Ω à
20 °C (68 °F)Ω × 1
3. Contrôler:
Résistance de bobine secondaire
Hors spécification → Remplacer.
Fil (+) de multimètre →
Fil orange 1
Fil (–) de multimètre →
Borne de bougie 2
Résistance de
bobine
secondairePosition de
sélecteur du
multimètre
4,6 à 6,8 kΩ à
20 °C (68 °F)kΩ × 1
4. Contrôler:
Partie étanche de la bobine
d’allumage a
Broche de la bougie b
Filetage de la bougie c
Usé → Remplacer.
SYSTEME D’ALLUMAGE

6 - 19
–+ELECIGNITION SYSTEM
AC MAGNETO INSPECTION
1. Inspect:
Pickup coil resistance
Out of specification
→
Replace.
Tester (+) lead →
Red lead 1

Tester (–) lead →
White lead 2

Pickup coil
resistanceTester
selector
position
248 ~ 372 Ω
at
20 °C (68 °F)Ω
×
100
RW
12
NEUTRAL SWITCH INSPECTION
1. Inspect:
Neutral switch conduct
No continuity while in neutral
→
Replace.
Continuity while in gear
→ Replace. Tester (+) lead →

Sky blue lead 1
Tester (–) lead →
Ground 2

Sb
1
Ground
2
Tester
selector
position
NEUTRAL
Ω
×
1
IN GEAR
–+ Ω×1
1
2L/W Sb
EC628000CDI UNIT INSPECTION
Check all electrical components. If
no fault is found, replace the CDI
unit. Then check the electrical com-
ponents again.INSPECTION DE LA MAGNETO
CA
1. Contrôler:
Résistance de bobine d’excitation
Hors spécification → Remplacer.
Fil (+) de multimètre → Fil rouge 1
Fil (–) de multimètre → Fil blanc 2
Résistance de
bobine
d’excitationPosition de
sélecteur du
multimètre
248 à 372 Ω à
20 °C (68 °F)Ω × 100
CONTROLE DU CONTACTEUR DE
POINT MORT
1. Contrôler:
Continuité du contacteur de point
mort
Pas de continuité quand au point mort →
Remplacer.
Continuité quand vitesse engagée →
Remplacer.Fil (+) de multimètre →
Fil bleu ciel 1
Fil (–) de multimètre → Masse 2
Sb
1 Masse
2 Position de
sélecteur du
multimètre
Point mort
Ω × 1
Embrayé
CONTROLE DU BLOC CDI
Vérifier tous les équipements électri-
ques. Si aucun défaut n’est trouvé, rem-
placer le bloc CDI, puis vérifier à
nouveau les équipements électriques.
SYSTEME D’ALLUMAGE

6 - 53
–+ELECTHROTTLE POSITION SENSOR SYSTEM
THROTTLE POSITION SENSOR SYSTEM
INSPECTION STEPS
If the throttle position sensor will not operate, use the following inspection steps.
NOTE:Use the following special tools in this inspection.
Check entire ignition
system for connection.Repair or replace.
Check throttle position sensor.Throttle position
sensor coilReplace.
Check CDI unit.Throttle position
sensor input
voltageReplace.
Pocket tester:
YU-3112-C/
90890-03112
Inductive tachometer:
YU-8036-B
Engine tachometer:
90890-03113
No good
OK
No good
OK
No good