2004 YAMAHA YZ250F lock

5 - 58
CHAS
AMORTISSEUR ARRIERE
FEDERBEIN
AMMORTIZZATORE POSTERIORE
FEDERBEIN
Demontage-Arbeiten:1 Federbein demontieren2 Federbein zerlegen
Demontage-ArbeitenReihen-
folgeBauteil Anz. Bemerkungen
Vorbereitung für den AusbauFEDERBEIN DEMONTIEREN
Das Motorrad am Motor aufbocken.
WARNUNGDas Motorrad gegen Umfallen sichern.
Sitz und Paßband Siehe Abschnitt “SITZBANK, KRAFTSTOFFTANK
UND SEITENABDECKUNGEN” in KAPITEL 4.
Schalldämpfer Siehe Abschnitt “KRÜMMER UND SCHALLDÄMP-
FER” in KAPITEL 4.
1 Schlauchschelle (Luftfilteranschluß) 1 Nur lockern.
2 Rahmenhinterteil 1
3 Schraube (Umlenkhebel, Federbein) 1 Die Schwinge festhalten.
4 Schraube (Federbein, Rahmen) 1
5 Federbein 1
6 Sicherungsmutter 1 Nur lockern.
7 Einstellmutter 1 Nur lockern.
8 Unterer Federsitz 1
1
2
AMORTISSEUR ARRIERE
Organisation de la dépose:1 Dépose de l’amortisseur arrière2 Démontage de l’amortisseur arrière
Organisation de la dépose Ordre Nom de pièce QtéRemarques
Préparation pour la déposeDEPOSE DE L’AMORTISSEUR ARRIERE
Maintenir la machine en plaçant un support
approprié sous le moteur.
AVERTISSEMENT
Bien soutenir la machine afin qu’elle ne risque
pas de se renverser.
Selle et ruban d’ajustement Se référer à la section “SELLE, RESERVOIR DE CAR-
BURANT ET CACHES LATERAUX” du CHAPITRE 4.
Silencieux Se référer à la section “TUYAU D’ECHAPPEMENT ET
SILENCIEUX” du CHAPITRE 4.
1 Bride (raccord de filtre à air) 1 Desserrer uniquement.
2 Cadre arrière 1
3 Boulon (amortisseur arrière-bras de relais) 1 Tenir le bras oscillant.
4 Boulon (amortisseur arrière-cadre) 1
5 Amortisseur arrière 1
6 Contre-écrou 1 Desserrer uniquement.
7 Dispositif de réglage 1 Desserrer uniquement.
8 Guide de ressort inférieur 1
1
2
AMMORTIZZATORE POSTERIORE
Portata dello smontaggio:1 Rimozione ammortizzatore posteriore2 Smontaggio ammortizzatore posteriore
Portata dello smontaggio Ordine Denominazione QuantitàOsservazioni
Preparazione per la rimozioneRIMOZIONE AMMORTIZZATORE
POSTERIORE
Mantenere il veicolo posizionando un supporto
idoneo sotto al motore.
AVVERTENZASostenere saldamente il veicolo in modo che non ci siail rischio che si rovesci.
Sella e fascia di regolazione Fare riferimento al paragrafo “SELLA, SERBATOIO
CARBURANTE E CARENATURA LATERALE” nel
CAPITOLO 4.
Silenziatore Fare riferimento al paragrafo “TUBO DI SCARICO E
SILENZIATORE” nel CAPITOLO 4.
1 Morsetto (giunto filtro dell’aria) 1 Allentare soltanto.
2 Telaio posteriore 1
3 Bullone (ammortizzatore posteriore - leva di
rinvio)1 Sostenere il forcellone oscillante.
4 Bullone (ammortizzatore posteriore - telaio) 1
5 Ammortizzatore posteriore 1
6 Controdado 1 Allentare soltanto.
7 Registro 1 Allentare soltanto.
8 Guida molla inferiore 1
1
2

5 - 63
CHASREAR SHOCK ABSORBER
2. Tighten:
Adjuster 1
3. Adjust:
Spring length (installed) a
* For EUROPE
NOTE:
The length of the spring (installed) changes
1.5 mm (0.06 in) per turn of the adjuster.
CAUTION:
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
Spring length (installed) a:
Standard
lengthExtent of
adjustment
249 mm (9.80 in)
*264.5 mm (10.41 in)240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)
*255.5 ~ 273.5 mm
(10.06 ~ 10.77 in)
4. Tighten:
Locknut 1
Rear shock absorber
1. Install:
Dust seal 1
O-ring 2
Collar 3
NOTE:
Apply the molybdenum disulfide grease on
the bearing.
Apply the lithium soap base grease on the
dust seals, O-rings and collars.

–+ELEC

SYSTEME D’ALLUMAGE
ZÜNDANLAGE
IMPIANTO DI ACCENSIONE
ZÜNDFUNKENSTRECKE KON-
TROLLIEREN
1. Den Zündkerzenstecker von
der Zündkerze abziehen.
2. Den Zündspulendeckel aus-
bauen.
3. Den Zündfunkenstreckente-
ster
1 (bzw. 2) wie abgebil-
det anschließen.
Zündspule 3
Zündkerze 4
ÅNur USA und CDN
ıNicht USA und CDN
4.Den Motor mit dem Kick-
starter durchdrehen
.
5. Die Zündfunkenstrecke kon-
trollieren.
6. Den Motor anlassen und die
Zündfunkenstrecke vergrö-
ßern, bis es zu Fehlzündungen
kommt (nur USA und CDN).
Min. Zündfunkenstrecke:
6,0 mm (0,24 in)
STECKVERBINDER-, KABEL- UND
ZÜNDSPULENANSCHLÜSSE
KONTROLLIEREN
1. Kontrollieren:
Steckverbinder- und Kabel-
anschlüsse
Rost/Staub/Lockerheit/Kurz-
schluß → Instand setzen
oder erneuern.
Zündspule und Zündkerze
wie angebracht
Die Zündspule eindrücken,
bis sie das Zündkerzenloch
im Zylinderkopfdeckel fest
berührt.
MOTORSTOPPSCHALTER
KONTROLLIEREN
1. Kontrollieren:
Motorstoppschalter
(auf Durchgang)
Kein Durchgang bei gedrücktem
Schalter → Erneuern.
Durchgang bei freigelassenem
Schalter → Erneuern. Meßkabel (+) →
schwarz/weiß 1
Meßkabel (–) → schwarz 2
B/W
1 B
2 Meßge-
rät-
Einstel-
GE-
DRÜCKT
Ω × 1
FREI
TEST DE LA LONGUEUR D’ETIN-
CELLE D’ALLUMAGE
1. Déconnecter le capuchon de bou-
gie de la bougie.
2. Déposer le capuchon de la bobine
d’allumage.
3. Connecter le testeur dynamique
d’étincelle 1 (testeur d’allu-
mage 2) comme indiqué.
Bobine d’allumage 3
Bougie 4
ÅPour les USA et le CDN
ıExcepté pour les USA et le 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. (unique-
ment USA et CDN)
Longueur d’étincelle mini-
mum:
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
telles quelles
Insérer la bobine d’allumage
jusqu’à ce qu’elle touche le
trou de bougie dans le couver-
cle de la culasse.
CONTROLE DU COUPE-CIRCUIT
DU MOTEUR
1. Vérifier:
Continuité du coupe-circuit du
moteur
Pas de continuité lorsqu’enfoncé →
Remplacer.
Continuité lorsque relâché → Rempla-
cer.Fil (+) de multimètre →
Fil noir/blanc 1
Fil (–) de multimètre →
Fil noir 2
B/W
1B
2Position de
sélecteur
du multi-
mètre
EN-
FONCE
Ω × 1
RE-
LACHE
6 - 4
TEST DELLA DISTANZA TRA GLI
ELETTRODI
1. Staccare il cappuccio della candela.
2. Rimuovere il cappuccio della
bobina di ignizione.
3. Collegare il tester della dinamicità
della scintilla 1 (tester dell’accen-
sione 2) come illustrato.
Bobina di accensione 3
Candela 4
ÅPer USA e CDN
ıTranne USA e CDN
4. Agire sulla pedivella di avvia-
mento.
5. Controllare la distanza tra gli elet-
trodi.
6. Avviare il motore ed aumentare la
distanza tra gli elettrodi fino a che
non si verifica uno scatto a vuoto.
(Solo per USA e CDN)
Distanza minima tra gli
elettrodi:
6,0 mm (0,24 in)
ISPEZIONE DEL COLLEGA-
MENTO DEGLI ACCOPPIATORI,
DEI CAVI E DELLA BOBINA DI
IGNIZIONE
1. Controllare:
Collegamento degli accoppia-
tori e dei cavi
Ruggine/polvere/allentamento/
cortocircuito → Riparare o
sostituire.
Collocazione della bobina di
ignizione e della candela
Spingere in dentro la bobina di
ignizione fino a che è in stretto
contatto con il foro candela nel
coperchio della testata cilindro.
ISPEZIONE DELL’INTERRUT-
TORE DI ARRESTO DEL MOTORE
1. Ispezionare:
Conduzione interruttore di
arresto motore
Assenza di continuità se premuto →
Sostituire.
Continuità se rilasciato→ Sostituire. Conduttore (+) del tester →
Conduttore nero/bianco 1
Conduttore (–) del tester →
Conduttore nero 2
B/W
1B
2Posizione
selettore
tester
PRE-
MUTO
Ω × 1
RILA-
SCIATO

–+ELEC
HINWEIS ZUM UMGANG
ACHTUNG:
Nicht die Schrauben (Drosselposi-
tionssensor, TPS) 1 lösen, ausge-
nommen wenn der Drosselpositi-
onssensor aufgrund von
Fehlfunktion ausgetauscht wer-
den muß, denn dadurch wird ein
Nachlassen der Motorleistung be-
wirkt.
INSPEKTION DER STECKVERBIN-
DUNGEN UND KABELANSCHLÜS-
SE
1. Prüfen:
Steckverbindungen und Ka-
belanschlüsse
Rost/Staub/Lockerung/Kurz-
schluß → Reparieren oder
austauschen.
INSPEKTION DER TPS-SPULE
1. Prüfen:
Widerstand der Drosselklap-
pen-Positionssensor-Spule
Außerhalb des Sollwerts →
Austauschen.
Prüfgerätkabel (+) → Blau 1
Prüfgerätkabel (–) →
Schwarz 2
Widerstand der
Drosselklappen-Positionssen-
sor-Spule
Prüfgeräte-
instellung
4–6 kΩ
bei 20 ˚C
(68 ˚F)kΩ × 1
2. Lockerung:
Drosselklappen-Anschlag-
schraube 1
HINWEIS:
Die Drosselklappen-Anschlag-
schraube herausdrehen, bis die
Drosselklappenwelle vollständig ge-
schlossen ist. REMARQUE
ATTENTION:
Ne pas desserrer les vis (capteur de
position des gaz) 1 sauf s’il faut chan-
ger le capteur de position en raison
d’un problème, sinon le moteur sera
moins performant.
CONTROLE DES CONNEXIONS
DES COUPLEURS ET DES FILS
1. Vérifier:
Connexion coupleurs et fils
Rouille/poussière/desserre-
ment/court-circuit → Réparer
ou remplacer.
CONTROLE DE LA BOBINE DE
CAPTEUR DE PAPILLON DES GAZ
1. Contrôler:
Résistance de la bobine du cap-
teur de papillon des gaz
Hors spécifications → Rempla-
cer.
Fil (+) de multinètre → Fil bleu 1
Fil (–) de multinètre → Fil noir 2
Fiche rapide de fil de
capteur de position
de papillon des gaz Position du
sélecteur de
l’appareil de
contrôle
4 à 6 kΩ à
20 ˚C (68 ˚F)kΩ × 1
2. Serrer:
Vis d’arrêt d’accélérateur 1
N.B.:
Tourner la vis d’arrêt d’accélérateur
jusqu’à ce que l’axe de l’accélérateur
soit en position de fermeture complète.NOTA SUL MANEGGIO
ATTENZIONE:
Non allentare le viti (sensore di posi-
zione della valvola a farfalla) 1
tranne quando si cambia il sensore di
posizione della valvola a farfalla a
causa di guasti, perché questo causa
una diminuzione delle prestazioni del
motore.
ISPEZIONE DEI COLLEGAMENTI
DEGLI ACCOPPIATORI E DEI
CAVI
1. Controllare:
Collegamento degli accoppia-
tori e dei cavi
Ruggine/polvere/allentamento/
cortocircuito → Riparare o
sostituire.
ISPEZIONE BOBINA SENSORE
DELLA POSIZIONE DELLA VAL-
VOLA A FARFALLA
1. Ispezionare:
Resistenza bobina sensore di
posizione della valvola a far-
falla
Fuori specifica → Regolare.
Conduttore (+) del tester →
Conduttore blu 1
Conduttore (–) del tester →
Conduttore nero 2
Resistenza bobina
sensore di posizione
della valvola a far-
fallaPosizione
selettore
tester
4 ~ 6 kΩ a
20 ˚C (68 ˚F)kΩ × 1
2. Allentare:Vite di arresto della valvola a
farfalla 1
NOTA:
Svitare la vite di arresto della valvola a
farfalla finché l’albero della valvola a
farfalla non si trova in posizione di com-
pleta chiusura. CIRCUIT DU CAPTEUR DE PAPILLON DES GAZ
DROSSELKLAPPEN-POSITIONSSENSOR
SISTEMA SENSORE DELLA POSIZIONE DELLA VALVOLA A FARFALLA
6 - 8

7 - 13
TUNSETTING
EC722011
Front fork setting
The front fork setting should be made depend-
ing on the rider’s feeling of an actual run and
the circuit conditions.
The front fork setting includes the following
three factors:
1. Setting of air spring characteristics
Change the fork oil level.
2. Setting of spring preload
Change the spring.
Install the adjustment washer.
3. Setting of damping force
Change the compression damping.
Change the rebound damping.
The spring acts on the load and the
damping force acts on the cushion
travel speed.
EC723001
Change in level and characteristics of fork
oil
Damping characteristic near the final stroke can
be changed by changing the fork oil amount.
CAUTION:
Adjust the oil level in 5 mm (0.2 in) incre-
ments or decrements. Too low oil level
causes the front fork to produce a noise at
full rebound or the rider to feel some pres-
sure on his hands or body. Alternatively,
too high oil level will develop unexpectedly
early oil lock with the consequent shorter
front fork travel and deteriorated perfor-
mance an characteristics. Therefore, adjust
the front fork within the specified range.
ÅAir spring characteristics in relation to oil level
change
ıLoad
ÇStroke
1Max. oil level
2Standard oil level
3Min. oil level
Standard oil level:
125 mm (4.92 in)
Extent of adjustment:
105 ~ 135 mm (4.13 ~ 5.31 in)
From top of outer tube with
inner tube and damper rod fully
compressed without spring.

7 - 17
TUN
EC72B000
Rear suspension setting
The rear suspension setting should be made
depending on the rider’s feeling of an actual
run and the circuit conditions.
The rear suspension setting includes the fol-
lowing two factors:
1. Setting of spring preload
Change the set length of the spring.
Change the spring.
2. Setting of damping force
Change the rebound damping.
Change the compression damping.
EC72C001
Choosing set length
1. Place a stand or block under the engine
to put the rear wheel above the floor, and
measure the length a between the rear
wheel axle center and the rear fender
holding bolt.
2. Remove the stand or block from the
engine and with a rider astride the seat,
measure the sunken length b between
the rear wheel axle center and the rear
fender holding bolt.
3. Loosen the locknut 1 and make adjust-
ment by turning the spring adjuster 2 to
achieve the standard figure from the sub-
traction of the length b from the length
a.
Standard figure:
90 ~ 100 mm (3.5 ~ 3.9 in)
SETTING

7 - 21
TUNSETTING
EC72H002
Suspension setting
Front fork
NOTE:
If any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
Before any change, set the rear shock absorber sunken length to the standard figure 90 ~
100 mm (3.5 ~ 3.9 in).
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff over entire range

Compression damping
Oil level (oil amount)
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with soft spring.
Unsmooth movement
over entire range

Outer tube
Inner tube
Under bracket tightening
torqueCheck for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Retighten to specified torque.
Poor initial
movement

Rebound damping
Oil sealTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Apply grease in oil seal wall.
Soft over entire range,
bottoming out

Compression damping
Oil level (oil amount)
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Increase oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).
Replace with stiff spring.
Stiff toward stroke end
Oil level (oil amount) Decrease oil level by about 5 mm (0.2 in).
Soft toward stroke end,
bottoming out
Oil level (oil amount) Increase oil level by about 5 mm (0.2 in).
Stiff initial movement
Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front posture

Compression damping
Rebound damping
Balance with rear end
Oil level (oil amount)Turn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in) when
one passenger is astride seat (lower rear posture).
Increase oil level by about 5 mm (0.2 in).
“Obtrusive” front, tend-
ing to upper front pos-
ture

Compression damping
Balance with rear end
Spring
Oil lever (oil amount)Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in) when
one passenger is astride seat (upper rear posture).
Replace with soft spring.
Decrease oil level by about 5 ~ 10 mm (0.2 ~ 0.4 in).

7 - 22
TUNSETTING
Rear shock absorber
NOTE:
If any of the following symptoms is experienced with the standard position as the base, make
resetting by reference to the adjustment procedure given in the same chart.
Adjust the rebound damping in 2-click increments or decrements.
Adjust the low compression damping in 1-click increments or decrements.
Adjust the high compression damping in 1/6 turn increments or decrements.
SymptomSection
Check Adjust
JumpLarge
gapMedium
gapSmall
gap
Stiff, tending to sink

Rebound damping
Spring set lengthTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Spongy and unstable

Rebound damping
Low compression damping
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Turn adjuster clockwise (about 1 click) to increase
damping.
Replace with stiff spring.
Heavy and dragging

Rebound damping
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Replace with soft spring.
Poor road gripping

Rebound damping
Low compression damping
High compression damp-
ing
Spring set length
SpringTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Turn adjuster clockwise (about 1 clicks) to increase
damping.
Turn adjuster clockwise (about 1/6 clicks) to increase
damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Replace with soft spring.
Bottoming out

High compression damp-
ing
Spring set length
SpringTurn adjuster clockwise (about 1/6 turn) to increase
damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger in astride seat.
Replace with stiff spring.
Bouncing

Rebound damping
SpringTurn adjuster clockwise (about 2 clicks) to increase
damping.
Replace with soft spring.
Stiff travel

High compression damp-
ing
Spring set length
SpringTurn adjuster counterclockwise (about 1/6 turn) to
decrease damping.
Set sunken length for 90 ~ 100 mm (3.5 ~ 3.9 in) when
one passenger is astride seat.
Replace with soft spring.