stop start YAMAHA YZ426F 2000 User Guide
Page 546 of 608
 
6 - 4
–+ELEC
 
IGNITION SYSTEM 
EC622001 
SPARK GAP TEST  
1. Disconnect the spark plug cap from spark
plug.
2. Connect the dynamic spark tester   
1  
(ignition checker   
2  
) as shown. 
l 
Spark plug cap   
3  
  
l 
Spark plug   
4  
  
 
For USA and CDN 
õ 
Except for USA and CDN 
3. Kick the kick starter.
4. Check the ignition spark gap.
5. Start engine, and increase spark gap until
misfire occurs. (for USA and CDN only) 
Minimum spark gap:
6.0 mm (0.24 in)
õ
 
EC624000 
COUPLERS AND LEADS CONNECTION 
INSPECTION 
1. Check: 
l 
Couplers and leads connection
Rust/dust/looseness/short-circuit  
®  
 
Repair or replace. 
EC625001 
“ENGINE STOP” BUTTON INSPECTION 
1. Inspect: 
l 
“ENGINE STOP” button conduct
No continuity while being pushed  
®  
 Replace.
Continuity while being freed  
®  
 Replace.  
Tester (+) lead  
® 
 Black/White lead   
1  
 
Tester (–) lead  
® 
 Black lead  
2  
  
B/W  
1 
B 
2 
Tester selec-
tor position
PUSH IN 
W  
   
´  
 1
FREE 
Page 547 of 608
–+ELEC
 
SYSTEME D’ALLUMAGE 
ZÜNDANLAGE 
ZÜNDFUNKENSTRECKE KONTROLLIEREN 
1. Den Zündkerzenstecker von der Zünd-
kerze abziehen.
2. Den Zündfunkenstreckentester  
1  
 (bzw.   
2 
) wie abgebildet anschließen. 
l 
Zündkerzenstecker  
3 
  
l 
Zündkerze  
4 
  
 
Nur USA und CAN 
õ 
Nicht USA und CAN 
3. Den Motor mit dem Kickstarter durchdre-
hen.
4. Die Zündfunkenstrecke kontrollieren.
5. Den Motor anlassen und die Zündfunken-
strecke vergrößern, bis es zu Fehlzün-
dungen kommt (nur USA und CAN). 
Min. Zündfunkenstrecke
6,0 mm
MOTORSTOPPSCHALTER “ENGINE STOP” 
KONTROLLIEREN 
1. Kontrollieren:
 
l 
Motorstoppschalter
(auf Durchgang)
Kein Durchgang bei gedrücktem Schalter  
®  
Erneuern.
Durchgang bei freigelassenem Schalter  
® 
 Er-
neuern. 
Meßkabel (+)  
® 
 schwarz/weiß  
1 
 
Meßkabel (–)  
® 
 schwarz  
2 
  
B/W  
1 
 B 
2 
 Meßgerät-
Einstellung
GE-
DRÜCK
W ´ 1
FREI
TEST DE L’INTERVALLE 
D’ETINCELLEMENT D’ALLUMAGE
1. Déconnecter le capuchon de bougie de la
bougie.
2. Connecter le testeur dynamique d’étincelle 1
(testeur d’allumage 2) comme indiqué.
lCapuchon de bougie 3 
lBougie 4 
Pour les E.-U. et le Canada 
õExcepté pour les E.-U. et le Canada
3. Actionner le démarreur au pied.
4. Contrôler la longueur d’étincelle d’allumage.
5. Démarrer le moteur et augmenter la longueur
d’étincelle jusqu’à ce qu’un raté se produise.
(uniquement E.-U. et Canada)
Longueur d’étincelle minimum:
6,0 mm (0,24 in)
CONTROLE DES CONNEXIONS DE 
COUPLEURS ET FILS
1. Contrôler:
lConnexion de coupleurs et fils
Rouille/poussière/jeu/court-circuit ® 
Réparer ou changer.
CONTROLE DU BOUTON D’ARRET DU 
MOTEUR “ENGINE STOP”
1. Vérifier:
lContinuité du bouton d’arrêt du moteur
“ENGINE STOP”
Pas de continuité lorsqu’enfoncé ® Changer.
Continuité lorsque relâché ® Changer. Fil (+) de testeur ® Fil noir/blanc 1 
Fil (–) de testeur ® Fil noir 2 
B/W 
1 B
2 Position de 
sélecteur de 
testeur
EN-
FONCE
W ´ 1
RE-
LACHE
6 - 4
STECKVERBINDER- UND KABEL-
ANSCHLÜSSE KONTROLLIEREN
1. Kontrollieren:
lSteckverbinder- und Kabelanschlüsse
Rost/Staub/Lockerheit/Kurzschluß ® 
Instand setzen oder erneuern. 
Page 562 of 608
 
7 - 1
TUN
 
EC700000 
TUNING 
EC710000 
ENGINE 
Carburetor setting 
l 
The air/fuel mixture will vary depending on
atmospheric conditions. Therefore, it is nec-
essary to take into consideration the air pres-
sure, ambient temperature, humidity, etc.,
when adjusting the carburetor. 
l 
Perform a test run to check for proper engine
performance (e.g., throttle response) and
spark plug(-s) discoloration or fouling. Use
these readings to determine the best possi-
ble carburetor setting.
NOTE:
 
It is recommended to keep a record of all car-
buretor settings and external conditions (e.g.,
atmospheric conditions, track/surface condi-
tions, lap times) to make future carburetor set- 
ting easier.
WARNING
 
l 
The carburetor is a part of the fuel line.
Therefore, be sure to install it in a well-
ventilated area, away from flammable
objects and any sources of fire. 
l 
Never look into the carburetor intake.
Flames may shoot out from the pipe if the
engine backfires while it is being started.
Gasoline may be discharged from the
accelerator pump nozzle when the carbu- 
retor has been removed.
CAUTION:
 
l 
The carburetor is extremely sensitive to
foreign matter (dirt, sand, water, etc.).
During installation, do not allow foreign
matter to get into the carburetor. 
l 
Always handle the carburetor and its com-
ponents carefully. Even slight scratches,
bends or damage to carburetor parts may
prevent the carburetor from functioning
correctly. Carefully perform all servicing
with the appropriate tools and without
applying excessive force. 
l 
When the engine is stopped or when
riding at no load, do not open and close
the throttle unnecessarily. Otherwise, too
much fuel may be discharged, starting
may become difficult or the engine may
not run well. 
SETTING 
7