2006 YAMAHA YZ250F stop start

3 - 18
INSP
ADJ
ENGINE IDLING SPEED ADJUSTMENT
1. Start the engine and thoroughly warm it up.
2. Adjust:
Engine idling speed
Adjustment steps:
Adjust the pilot screw.
Refer to “PILOT SCREW ADJUSTMENT”
section.
Turn the throttle stop screw 1 until the
specified engine idling speed.
NOTE:
Using a digital engine tachometer for idle
speed adjustment, detect the engine idling
speed by bringing the sensing element c of
the engine tachometer close to the ignition
coil 2.
To increase idle speed → Turn the throt-
tle stop screw 1 in a.
To decrease idle speed → Turn the throt-
tle stop screw 1 out b.
Engine idling speed:
1,900 ~ 2,100 r/min
c2
VALVE CLEARANCE INSPECTION AND
ADJUSTMENT
NOTE:
The valve clearance should be adjusted
when the engine is cool to the touch.
The piston must be at Top Dead Center
(T.D.C.) on compression stroke to check or
adjust the valve clearance.
1. Remove:
Seat
Fuel tank
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
ENGINE IDLING SPEED ADJUSTMENT/
VALVE CLEARANCE INSPECTION AND ADJUSTMENT

ENG
4 - 13
2. Kontrollieren:
Hauptdüse
1
Leerlaufdüse
2
Nadeldüse
3
Chokedüse
4
Leerlauf-Luftdüse
5
Ausströmdüse
6
Beschädigt
→ Erneuern.
Verunreinigt
→ Reinigen.
HINWEIS:
Zum Reinigen ein Lösungsmittel
auf Petroleumbasis verwenden.
Sämtliche Kanäle und Düsen mit
Druckluft ausblasen.
Niemals einen Draht verwenden.
Nadelventil
1. Kontrollieren:
Nadelventil
1
Ventilsitz
2
Riefig
a
→ Erneuern.
Verstaubt
b
→ Reinigen.
Filter
c
Verstopft
→ Reinigen.
Drosselklappe
1. Kontrollieren:
Leichtgängigkeit
Fest
→ Instand setzen, ggf.
erneuern.
HINWEIS:
Die Drosselklappe
1 in das Verga-
sergehäuse einsetzen und deren
Leichtgängigkeit kontrollieren.
Düsennadel
1. Kontrollieren:
Düsennadel
1
Verbogen/verschlissen
→
Erneuern.
Clip-Nut
Spiel vorhanden/verschlissen
→ Erneuern.
Clipposition
Standard-Clipposition:
3. Nut
2. Contrôler:
Gicleur principal 1
Gicleur de ralenti 2
Gicleur d’aiguille 3
Gicleur de starter 4
Gicleur d’air de ralenti 5
Gicleur de fuite 6
Endommagement → Remplacer.
Encrassé → Nettoyer.
N.B.:
Nettoyer avec un solvant à base de
pétrole. Nettoyer tous les conduits et
gicleurs à l’air comprimé.
Ne jamais utiliser de fil métallique.
Pointeau
1. Contrôler:
Pointeau 1
Siège de pointeau 2
Usure en creux a → Remplacer.
Poussière b → Nettoyer.
Filtre c
Bouché → Nettoyer.
Papillon des gaz
1. Contrôler:
Mouvement
Coincement → Réparer ou rem-
placer.
N.B.:
Insérer le papillon des gaz 1 dans le
corps du carburateur et contrôler qu’il
coulisse librement.
Aiguille
1. Contrôler:
Aiguille 1
Déformation/usure → Rempla-
cer.
Rainure du clip
Jeu/usure → Remplacer.
Position du clip
Position standard du clip:
Rainure n°3
2. Controllare:
Getto del massimo 1
Getto del minimo 2
Getto a spillo 3
Getto starter 4
Getto aria del minimo 5
Getto di perdita 6
Danno → Sostituire.
Contaminazione → Pulire.
NOTA:
Per la pulizia, utilizzare un solvente a
base di petrolio. Pulire tutti i passaggi
e i getti con aria compressa.
Non utilizzare mai un filo metallico.
Valvola a spillo
1. Controllare:
Valvola a spillo 1
Sede della valvola 2
Usura scanalatura a → Sostitu-
ire.
Polvere b → Pulire.
Filtro c
Ostruito → Pulire.
Valvola a farfalla
1. Controllare:
Movimento libero
Bloccata → Riparare o sostituire.
NOTA:
Inserire la valvola a farfalla 1 nel corpo
del carburatore e controllare il movi-
mento libero.
Spillo del getto
1. Controllare:
Spillo del getto 1
Deformazioni/usura → Sostituire.
Scanalatura fermo
Presenza di gioco/usura → Sosti-
tuire.
Posizione del fermo
Posizione standard del
fermo:
Scanalatura n.3
CARBURATEUR
VERGASER
CARBURATORE

4 - 17
ENGCARBURETOR
8. Install:
Throttle shaft assembly 1
Washer (metal) 2
Washer (resin) 3
Valve lever 4
NOTE:
Apply the fluorochemical grease on the bear-
ings.
Fit the projection a on the throttle shaft
assembly into the slot b in the throttle posi-
tion sensor.
Make sure the stopper c of the spring fits
into the recess in the carburetor.
Turn the throttle shaft assembly left while
holding down the lever 1 5 and fit the throt-
tle stop screw tip d to the stopper e of the
throttle shaft assembly pulley.
1
23
4
b
a
c
e
d
5
9. Install:
Push rod 1
NOTE:
While holding down the lever 1 2, insert the
push rod farthest into the carburetor.12
10. Install:
Starter jet 1
Pilot jet 2
Spacer 3
Needle jet 4
Main jet 5

5 - 43
CHASHANDLEBAR
EC5B0000
HANDLEBAR
Extent of removal:
1 Handlebar removal
Extent of removal Order Part name Q’ty Remarks
Preparation for removal
HANDLEBAR REMOVAL
Number plate Remove the band only.
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
5 Engine stop switch 1
6 Brake master cylinder 1 Refer to “REMOVAL POINTS”.
7 Throttle cable cap 1
8 Throttle cable #1 (pulled) 1 Disconnect at the throttle side.
9 Throttle cable #2 (pushed) 1 Disconnect at the throttle side.
10 Right grip 1 Refer to “REMOVAL POINTS”.
11 Tube guide 1
12 Collar 1
13 Left grip 1 Refer to “REMOVAL POINTS”.
14 Handlebar upper holder 2
15 Handlebar 1
16 Handlebar lower holder 2
1

5 - 43
CHAS
LENKER
Arbeitsumfang:
1 Lenker demontieren
ArbeitsumfangReihen-
folgeBauteil Anz. Bemerkungen
VorbereitungsarbeitenLENKER DEMONTIEREN
Nummernschild Nur das Band entfernen.
1 Warmstartzug 1 Hebelseitig lösen.
2 Warmstarthebel-Halterung 1
3 Kupplungszug 1 Hebelseitig lösen.
4 Kupplungshebel-Halterung 1
5 Motorstoppschalter 1
6 Hauptbremszylinder 1 Siehe unter “DEMONTAGE-EINZELHEITEN”.
7 Gaszug-Abdeckung 1
8 Gasgeberzug 1 1 Gasdrehgriffseitig lösen.
9 Gasnehmerzug 2 1 Gasdrehgriffseitig lösen.
10 Lenkergriff rechts 1 Siehe unter “DEMONTAGE-EINZELHEITEN”.
11 Führung 1
12 Distanzhülse 1
13 Lenkergriff links 1 Siehe unter “DEMONTAGE-EINZELHEITEN”.
14 Obere Lenker-Halterung 2
15 Lenker 1
16 Untere Lenker-Halterung 2
1
GUIDON
Organisation de la dépose:1 Dépose du guidon
Organisation de la dépose Ordre Nom de la pièce QtéRemarques
Préparation à la dépose
DEPOSE DU GUIDON
Plaque d’identification Déposer le collier uniquement.
1Câble de démarrage à chaud 1 Déconnecter du côté levier.
2 Support du levier de démarrage à chaud 1
3Câble d’embrayage 1 Déconnecter du côté levier.
4 Support de levier d’embrayage 1
5 Coupe-circuit du moteur 1
6Maître-cylindre de frein 1 Se reporter à “POINTS DE DEPOSE”.
7 Couvercle du logement de câble des gaz 1
8Câble des gaz n°1 (tiré)1Déconnecter du côté accélérateur.
9Câble des gaz n°2 (enfoncé)1Déconnecter du côté accélérateur.
10 Poignée droite 1 Se reporter à “POINTS DE DEPOSE”.
11 Guide de tube 1
12 Entretoise épaulée1
13 Poignée gauche 1 Se reporter à “POINTS DE DEPOSE”.
14 Support supérieur du guidon 2
15 Guidon 1
16 Support de guidon inférieur 2
1
MANUBRIO
Estensione della rimozione:1 Rimozione manubrio
Estensione della rimozione Ordine Denominazione QuantitàOsservazioni
Preparazione per la rimozione
RIMOZIONE MANUBRIO
Targa Rimuovere solo il nastro.
1 Cavo starter per partenze a caldo 1 Scollegare sul lato della leva.
2 Supporto leva starter per partenze a caldo 1
3 Cavo della frizione 1 Scollegare sul lato della leva.
4 Supporto della leva della frizione 1
5 Interruttore di arresto motore 1
6 Pompa del freno 1 Fare riferimento a “PUNTI DI RIMOZIONE”.
7 Copertura cavo acceleratore 1
8 Cavo acceleratore 1 (tirato) 1 Scollegare sul lato dell’acceleratore.
9 Cavo acceleratore 2 (premuto) 1 Scollegare sul lato dell’acceleratore.
10 Manopola destra 1 Fare riferimento a “PUNTI DI RIMOZIONE”.
11 Guida tubo 1
12 Collarino 1
13 Manopola sinistra 1 Fare riferimento a “PUNTI DI RIMOZIONE”.
14 Supporto superiore manubrio 2
15 Manubrio 1
16 Supporto inferiore manubrio 2
1
GUIDON
LENKER
MANUBRIO

5 - 48
CHASHANDLEBAR
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 dimensions shown.
•Pass the engine stop switch lead in the mid-
dle 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 ADJUSTMENT” sec-
tion in the CHAPTER 3.
•Hot starter lever free play
Refer to “HOT STARTER LEVER
ADJUSTMENT” section in the CHAPTER
3.

5 - 48
CHAS
11. Montieren:
Motorstoppschalter
1
Kupplungshebel-Halterung
2
Schraube (Kupplungshebel-
Halterung)
3
Warmstarthebel-Halterung
4
Schraube (Warmstarthebel-
Halterung)
5
Schlauchschelle
6
HINWEIS:
Der Motorstoppschalter, die Kupp-
lungshebel-Halterung und die
Schlauchklemme sind entspre-
chend den abgebildeten Maßen zu
montieren.
Das Motorstoppschalter-Kabel
durch die Mitte der Kupplungshe-
bel-Halterung führen.
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. Montieren:
Kupplungszug
1
Warmstartzug
2
HINWEIS:
Die Kupplungszug- und Warmstart-
zug-Enden mit Lithiumseifenfett
bestreichen.
13. Einstellen:
Kupplungshebel-Spiel
Siehe unter “KUPPLUNG EIN-
STELLEN” in KAPITEL 3.
Warmstarthebel-Spiel
Siehe unter “WARMSTART-
HEBEL EINSTELLEN” in
KAPITEL 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 à pince 6
N.B.:
Monter le coupe-circuit du moteur, le
support du levier d’embrayage et le
collier à pince 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 3.11. Installare:
Interruttore di arresto motore 1
Supporto della leva della frizione
2
Bullone (supporto della leva della
frizione) 3
Supporto leva starter per partenze
a caldo 4
Bullone (supporto leva starter per
partenze a caldo) 5
Morsetto 6
NOTA:
Installare l’interruttore di arresto
motore, il supporto della leva della fri-
zione e il morsetto in base alle dimen-
sioni indicate.
Far passare il cavo dell’interruttore di
arresto motore al centro del supporto
della leva della frizione.
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. Installare:
Cavo della frizione 1
Cavo starter per partenze a caldo
2
NOTA:
Applicare il grasso a base di sapone di
litio sull’estremità del cavo della frizione
e del cavo starter per partenze a caldo.
13. Regolare:
Gioco della leva della frizione
Fare riferimento al paragrafo
“REGOLAZIONE FRIZIONE”
nel CAPITOLO 3.
Gioco della leva starter per par-
tenze a caldo
Fare riferimento al paragrafo
“REGOLAZIONE LEVA STAR-
TER PER PARTENZE A
CALDO” nel CAPITOLO 3.
GUIDON
LENKER
MANUBRIO

6 - 4
–+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 (igni-
tion 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 connection
Rust/dust/looseness/short-circuit →
Repair or replace.
•Ignition coil and spark plug as they are fit-
ted
Push in the ignition coil until it closely
contacts the spark plug hole in the cylin-
der head cover.
ENGINE STOP SWITCH INSPECTION
1. Inspect:
•Engine stop switch conduct
No continuous while being pushed → Replace.
Continuous 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
Ω
× 1
FREE1 2
B/W B