ABS YAMAHA YZ250F 2007 Manual Online

5 - 65
CHAS
EC583000
REMOVAL POINTS
EC583320
Bearing
1. Remove:
•Stopper ring (upper bearing) 1
NOTE:
Press in the bearing while pressing its outer
race and remove the stopper ring.
2. Remove:
•Upper bearing 1
NOTE:
Remove the bearing by pressing its outer race.
3. Remove:
•Lower bearing 1
NOTE:
Remove the bearing by pressing its outer race.
EC584000
INSPECTION
Rear shock absorber
1. Inspect:
•Damper rod 1
Bends/damage → Replace rear shock
absorber assembly.
•Shock absorber 2
Oil leaks → Replace rear shock absorber
assembly.
Gas leaks → Replace rear shock
absorber assembly.
•Spring 3
Damage → Replace spring.
Fatigue → Replace spring.
Move spring up and down.
•Spring guide 4
Wear/damage → Replace spring guide.
•Spring seat 5
Cracks/damage → Replace.
•Bearing 6
Free play exists/unsmooth revolution/rust
→ Replace.
REAR SHOCK ABSORBER

5 - 66
CHASREAR SHOCK ABSORBER
EC585000
ASSEMBLY AND INSTALLATION
EC585300
Bearing
1. Install:
•Upper bearing 1
NOTE:
Install the bearing parallel until the stopper ring
groove appears by pressing its outer race.
CAUTION:
Do not apply the grease on the bearing
outer race because it will wear the rear
shock absorber surface on which the bear-
ing is press fitted.
2. Install:
•Stopper ring (upper bearing) 1
NOTE:
After installing the stopper ring, push back the
bearing until it contacts the stopper ring.
3. Install:
•Lower bearing 1
NOTE:
Install the bearing by pressing it on the side
having the manufacture’s marks or numbers.
Installed depth of the bearing
a:
4 mm (0.16 in)
Spring (rear shock absorber)
1. Install:
•Spring 1
•Upper spring guide 2
•Lower spring guide 3

5 - 67
CHASREAR SHOCK ABSORBER
2. Install:
•Spring seat 1
NOTE:
Install the spring seat with the projection a
brought into contact with the spring end, as
shown.
3. Tighten:
•Adjuster 1
4. Adjust:
•Spring length (installed)
Refer to “REAR SHOCK ABSORBER
SPRING PRELOAD ADJUSTMENT” sec-
tion in the CHAPTER 3.
5. Tighten:
•Locknut 1
Rear shock absorber
1. Install:
•Dust seal 1
•O-ring 2
•Collar 3
NOTE:
•Apply the molybdenum disulfide grease on
the dust seal lips and collars.
•Apply the lithium soap base grease on the O-
rings.

5 - 68
CHASREAR SHOCK ABSORBER
2. Install:
•Bushing 1
•Collar 2
•Dust seal 3
NOTE:
•Apply the molybdenum disulfide grease on
the bearing and dust seal lips.
•Install the dust seals with their lips facing out-
ward.
3. Install:
•Rear shock absorber
4. Install:
•Bolt (rear shock absorber-frame) 1
•Washer 2
•Nut (rear shock absorber-frame) 3
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
5. Install:
•Bolt (rear shock absorber-relay arm) 1
•Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
1 2
3
M
T R..56 Nm (5.6 m · kg, 40 ft · lb)
T R..53 Nm (5.3 m · kg, 38 ft · lb)
6. Install:
•Rear frame 1
•Bolt (rear frame) 2
T R..32 Nm (3.2 m · kg, 23 ft · lb)
7. Tighten:
•Bolt (air filter joint) 1
1
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)

–+ELEC
10. Die Ausrichtungsmarkierungen
a auf den Drosselklappensen-
sor und Vergaser ausrichten.
11. Den Motor abstellen.
12. Den Vergaser demontieren.
13. Festziehen:
Drosselklappensensor-
Schraube 1
HINWEIS:
Die Drosselklappensensor-Schrau-
ben mit einem T25-Einsatz festzie-
hen.
14. Den Vergaser montieren.
DROSSELKLAPPENSENSOR-
EINGANGSSPANNUNG
KONTROLLIEREN
1. Den Drosselklappensensor-
Steckverbinder lösen.
2. Den Motor starten.
3. Kontrollieren:
Drosselklappensensor-Ein-
gangsspannung
Nicht nach Vorgabe → Zünd-
box erneuern.
Messkabel (+) → Blau 1
Messkabel (–) → Schwarz/Blau 2
Drosselklappen-
sensor-Ein-
gangsspannungMessgerät-
Wahlschalter
4–6 V DCV-20
10. Placer les repères d’alignement a
sur le capteur de position du
papillon et le carburateur.
11. Arrêter le moteur.
12. Déposer le carburateur.
13. Serrer:
Vis (capteur de position de
papillon des gaz) 1
N.B.:
Serrer les vis (capteur de position de
papillon des gaz) à l’aide de la mèche
T25.
14. Monter le carburateur.
CONTROLE DE LA TENSION
D’ENTREE DU CAPTEUR DE
POSITION DE PAPILLON DES
GAZ
1. Débrancher la fiche rapide du cap-
teur de position de papillon des gaz.
2. Mettre le moteur en marche.
3. Contrôler:
Tension d’entrée du capteur de
position de papillon des gaz.
Hors spécifications → Remplacer
le boîtier CDI.
Fil (+) du multimètre → fil bleu 1
Fil (–) du multimètre →
fil noir/bleu 2
Tension d’entrée du
capteur de position
de papillon des gazPosition du
sélecteur du
multimètre
4 à 6 V DCV-20
10. Porre i segni di allineamento a sul
TPS e sul carburatore.
11. Arrestare il motore.
12. Rimuovere il carburatore.
13. Serrare:
Vite (sensore posizione farfalla)
1
NOTA:
Serrare le viti (sensore posizione far-
falla) mediante attrezzo con punta T25.
14. Installare il carburatore.
CONTROLLO TENSIONE IN
ENTRATA SENSORE POSIZIONE
FARFALLA
1. Scollegare l’accoppiatore del sen-
sore posizione farfalla.
2. Avviare il motore.
3. Controllare:
Tensione in entrata sensore posi-
zione farfalla
Non conforme alle specifiche →
Sostituire l’unità CDI.
Cavo (+) tester → Cavo blu 1
Cavo (–) tester → Cavo nero/blu 2
Tensione in
entrata sensore
posizione farfallaPosizione del
selettore del
tester
4 ~ 6 V DCV-20
SYSTEME DU CAPTEUR DE POSITION DE PAPILLON DES GAZ
DROSSELKLAPPENSENSOR
SISTEMA SENSORE POSIZIONE FARFALLA
6 - 10

TUN
ABSTIMMUNG
MOTOR
Vergaser-Abstimmung
Das Gemisch hängt u. a. von den
atmosphärischen Bedingungen ab.
Luftdruck, -temperatur und -feuch-
tigkeit sind Faktoren, die bei der
Vergaser-Abstimmung mit in
Betracht gezogen werden müssen.
Die Leistung und das Ansprech-
verhalten des Motors sowie der
Zustand der Kerze lassen sich am
besten im einem Testlauf prüfen.
Anhand dieser Ergebnisse kann
der Vergaser optimal eingestellt
werden.
HINWEIS:
Es empfiehlt sich, die jeweiligen
Umstände (atmosphärische Bedin-
gungen, Fahrbahnzustand, Anzahl
Runden usw.) und die entsprechen-
den Vergaser-Einstellungen zwecks
späterer Bezugnahme aufzuzeich-
nen.
WARNUNG
Der Vergaser ist ein Bestandteil
des Kraftstoffsystems. Bei
Arbeiten daher stets auf eine
gute Belüftung sorgen und Feu-
erquellen sowie entzündliche
Stoffe fern halten.
Niemals in den Vergasereinlass
hineinblikken. Beim Starten des
Motors könnten Flammen rück-
schlagen. Auch bei ausgebau-
tem Vergaser könnte Benzin aus
der Beschleunigungspumpe
entweichen.
MISE AU POINT
MOTEUR
Réglage du carburateur
Le mélange air/carburant varie en
fonction des conditions atmosphéri-
ques. Il est donc nécessaire de tenir
compte de la pression de l’air, de la
température ambiante, de l’humidité,
etc., pour le réglage du carburateur.
Effectuer un essai de conduite pour
contrôler les performances du moteur
(par ex. la réponse du moteur) et l’état
des bougies (décoloration ou encrasse-
ment). Utiliser les valeurs obtenues
pour effectuer le meilleur réglage pos-
sible du carburateur.
N.B.:
Il est recommandé de conserver un enre-
gistrement de tous les réglages du carbu-
rateur et des conditions extérieures
(conditions atmosphériques, conditions
de la piste/de la surface, temps intermé-
diaire) pour faciliter les réglages ulté-
rieurs du carburateur.
AVERTISSEMENT
Le carburateur fait partie du circuit
d’alimentation. Par conséquent,
veiller à effectuer le montage dans
un endroit bien aéré, à l’écart de
tout objet inflammable ou de toute
source d’incendie.
Ne jamais regarder dans l’admis-
sion du carburateur. Des flammes
peuvent surgir du tuyau en cas de
retour de flamme du moteur au
démarrage. De l’essence peut
s’écouler de l’injecteur de la pompe
de reprise lorsque le carburateur a
été déposé.
MESSA A PUNTO
MOTORE
Impostazione carburatore
La miscela aria/carburante varia a
seconda delle condizioni atmosferi-
che. Di conseguenza, durante la rego-
lazione del carburatore è necessario
tenere in considerazione la pressione
dell’aria, la temperatura
dell’ambiente, l’umidità ecc.
Eseguire un giro di prova per control-
lare l’efficienza del motore (ad es. la
reattività dell’acceleratore) e la pre-
senza di macchie o incrostazioni sulla/
e candela/e. Utilizzare queste letture
per determinare la migliore imposta-
zione possibile del carburatore.
NOTA:
Si consiglia di prendere nota di tutte le
impostazioni del carburatore e delle con-
dizioni esterne (ad es. condizioni atmo-
sferiche, condizioni del percorso e della
superficie, tempi per ogni giro) per sem-
plificare le successive impostazioni del
carburatore.
AVVERTENZA
Il carburatore fa parte del circuito
del carburante. Di conseguenza,
assicurarsi di installarlo in un
ambiente ben ventilato, lontano da
sostanze infiammabili e da ogni
fonte di fuoco.
Non guardare mai all’interno
dell’aspirazione del carburatore. Se
durante l’avvio il motore ha un
ritorno di fiamma, potrebbero svi-
lupparsi fiamme dal tubo. Quando
si toglie il carburatore, l’ugello della
pompa acceleratore può scaricare
benzina.
REGLAGE
EINSTELLUNG
REGISTRAZIONE
7 - 1





7

TUN
Einbaulänge wählen
1. Das Motorrad so am Motor auf-
bocken, dass das Hinterrad frei
in der Luft schwebt und dann
den Abstand a zwischen der
Mitte der Hinterachse und der
Hinterradabdekkungs-Schraube
messen.
2. Den Montageständer entfernen
und mit aufsitzendem Fahrer
erneut den Abstand b zwi-
schen der Mitte der Hinterachse
und der Hinterradabdeckungs-
Schraube messen.
3. Kontrollieren, ob die Differenz
zwischen den gemessenen
Abständen a und b dem Stan-
dardwert entspricht und ggf. ein-
stellen; dazu den Sicherungsring
1 lokkern und den Federvor-
spannring 2 entsprechend ver-
stellen.
HINWEIS:
•Bei neuen sowie eingefahrenen
Maschinen kann die Einbaulänge
sich verändern, wenn die Feder
allmählich ermüdet. Daher regel-
mäßig nachprüfen.
•Wenn der Standardwert für die
Einbaulänge der Feder nicht mehr
durch Einstellung erreichbar ist,
muss die Feder erneuert werden.
Standardwert:
90–100 mm (3,5–3,9 in)
Choix de la longueur de ressort
1. Placer un support ou un bloc sous le
moteur pour surélever la roue
arrière et mesurer la longueur a
entre le centre de l’axe de roue
arrière et le boulon de fixation du
garde-boue arrière.
2. Retirer le support ou le bloc et
mesurer, avec une personne assise
correctement sur la selle, la lon-
gueur b entre le centre de l’axe de
roue arrière et le boulon de fixation
du garde-boue arrière.
3. Desserrer le contre-écrou 1 et
effectuer le réglage en tournant le
dispositif de réglage 2 de manière
à atteindre la valeur standard, obte-
nue en soustrayant la longueur b
de la longueur a.
N.B.:
Si la moto est neuve et après qu’elle a
été rodée, la longueur du ressort peut
changer en raison de la fatigue initiale,
etc., du ressort. Il est donc important
de corriger les réglages régulièrement.
S’il est impossible d’atteindre la
valeur standard à l’aide du dispositif
de réglage et en ajustant la longueur
du ressort, remplacer le ressort par un
ressort en option et effectuer un nou-
veau réglage.
Valeur standard:
90 à 100 mm (3,5 à 3,9 in)
Scelta della lunghezza impostata.
1. Collocare un cavalletto o un fermo
sotto il motore per sollevare la ruota
posteriore dal pavimento e misu-
rare la distanza a tra il centro
dell’asse della ruota posteriore e il
bullone di bloccaggio del para-
fango posteriore.
2. Togliere il cavalletto o il fermo dal
motore e, con il conducente a bordo,
misurare l’affondamento b tra il
centro dell’asse della ruota poste-
riore e il bullone di bloccaggio del
parafango posteriore.
3. Allentare il controdado 1 e rego-
lare ruotando il dispositivo di rego-
lazione della molla 2 fino a
raggiungere un valore standard sot-
traendo l’affondamento b dalla
distanza a.
NOTA:
Se il mezzo è nuovo e ha effettuato il
rodaggio, la stessa lunghezza impo-
stata della molla può variare a causa
della fatica iniziale, ecc. della molla.
Assicurarsi quindi di eseguire una
nuova valutazione.
Se regolando il dispositivo di regola-
zione della molla o modificando la
lunghezza impostata della molla non
si raggiunge il valore standard, sostitu-
ire la molla e regolare di nuovo.
Valore standard:
90 ~ 100 mm (3,5 ~ 3,9 in)
REGLAGE
EINSTELLUNG
REGISTRAZIONE
7 - 16

7 - 17
TUNSETTING
Setting of spring after replacement
After replacement, be sure to adjust the spring
to the set length [sunken length 90 ~ 100 mm
(3.5 ~ 3.9 in)] and set it.
1. Use of soft spring
•Set the soft spring for less rebound
damping to compensate for its less spring
load. Run with the rebound damping
adjuster one or two clicks on the softer
side and readjust it to suit your prefer-
ence.
2. Use of stiff spring
•Set the soft spring for more rebound
damping to compensate for its greater
spring load. Run with the rebound damp-
ing adjuster one or two clicks on the
stiffer side and readjust it to suit your
preference.
*Adjusting the rebound damping will be fol-
lowed more or less by a change in the com-
pression damping. For correction, turn the
low compression damping adjuster on the
softer side.
CAUTION:
When using a rear shock absorber other
than currently installed, use the one whose
overall length
a does not exceed the stan-
dard as it may result in faulty performance.
Never use one whose overall length is
greater than standard.
Length
a of standard shock:
490 mm (19.29 in)

7 - 18
TUNSETTING
EC72Q000
Rear shock absorber setting parts
•Rear shock spring 1
[Equal-pitch titanium spring]
[Equal-pitch steel spring]
[Unequal-pitch steel spring]
CAUTION:
Install the spring seat
2 to the titanium
spring.
NOTE:
•The unequal-pitch spring is softer in initial
characteristic than the equal-pitch spring and
is difficult to bottom out under full compres-
sion.
•The I.D. mark a is marked at the end of the
spring.
•Spring specification varies according to the
color and quantity of I.D. marks.
TYPESPRING
RATESPRING
PART NUMBERI.D.
MARKSPRING
FREE
LENGTH
(approx.)
SOFT4.5
4.71C3-22212-00
1C3-22212-10Green
Red265
265
STD 4.9 1C3-22212-20 Black 265
STIFF5.1
5.3
5.5
5.71C3-22212-30
1C3-22212-40
1C3-22212-50
1C3-22212-60Blue
Yellow
Pink
White265
275
275
275
TYPESPRING
RATESPRING
PART NUMBERI.D.
MARK/
Q’TYSPRING
FREE
LENGTH
4.3 5UN-22212-00 Brown/1 260
TYPESPRING
RATE
(approx.)SPRING
PART NUMBERI.D.
MARK/
Q’TYSPRING
FREE
LENGTH
SOFT
STIFF4.5
4.7
4.9
5.1
5.3
5.5
5.75UN-22212-A0
5UN-22212-B0
5UN-22212-C0
5UN-22212-D0
5UN-22212-E0
5UN-22212-F0
5UN-22212-G0Green/2
Red/2
Black/2
Blue/2
Yellow/2
Pink/2
White/2275
275
275
275
275
275
275
a2 12

7 - 20
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 rangeCompression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil amount Decrease oil amount by about 5 ~ 10 cm
3 (0.2 ~
0.4 Imp oz, 0.2 ~ 0.3 US oz).
Spring Replace with soft spring.
Unsmooth movement
over entire rangeOuter tube Check for any bends, dents, and other noticeable
scars, etc. If any, replace affected parts.
Inner tube
Slide metal Replace with a new one for extended use.
Piston metal Replace with a new one for extended use.
Under bracket tightening
torqueRetighten to specified torque.
Poor initial
movementRebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Oil seal Apply grease in oil seal wall.
Soft over entire
range, bottoming outCompression damping Turn adjuster clockwise (about 2 clicks) to increase
damping.
Oil amount Increase oil amount by about 5 ~ 10 cm
3 (0.2 ~ 0.4
Imp oz, 0.2 ~ 0.3 US oz).
Spring Replace with stiff spring.
Stiff toward stroke
endOil amountDecrease oil amount by about 5 cm
3 (0.2 Imp oz,
0.2 US oz).
Soft toward stroke
end, bottoming outOil amountIncrease oil amount by about 5 cm
3 (0.2 Imp oz,
0.2 US oz).
Stiff initial movement Compression dampingTurn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Low front, tending to
lower front postureCompression damping Turn adjuster clockwise (about 2 clicks) to increase
damping.
Rebound damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 95 ~ 100 mm (3.7 ~ 3.9 in)
when one passenger is astride seat (lower rear pos-
ture).
Oil amount Increase oil amount by about 5 cm
3 (0.2 Imp oz,
0.2 US oz).
“Obtrusive” front,
tending to upper front
postureCompression damping Turn adjuster counterclockwise (about 2 clicks) to
decrease damping.
Balance with rear end Set sunken length for 90 ~ 95 mm (3.5 ~ 3.7 in)
when one passenger is astride seat (upper rear pos-
ture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about 5 ~ 10 cm
3 (0.2 ~ 0.4
Imp oz, 0.2 ~ 0.3 US oz).