2005 YAMAHA YZ250F ABS

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CHASREAR SHOCK ABSORBER
EC580000
REAR SHOCK ABSORBER
Extent of removal:
1 Rear shock absorber removal
2 Rear shock absorber disassembly
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER
REMOVAL
WARNING
Support the machine securely so
there is no danger of it falling over. Preparation for removal Hold the machine by placing the
suitable stand under the engine.
Seat and fitting band Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
Silencer Refer to “EXHAUST PIPE AND
SILENCER” section in the CHAPTER 4.
1 Clamp (air filter joint) 1 Only loosening.
2Rear frame 1
3 Bolt (rear shock absorber-relay
arm)1 Hold the swingarm.
4 Bolt (rear shock absorber-frame) 1
5 Rear shock absorber 1
6 Locknut 1 Only loosening.
7 Adjuster 1 Only loosening.
8 Lower spring guide 1
1
2

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CHAS
FEDERBEIN
Arbeitsumfang:
1 Federbein demontieren
2 Federbein zerlegen
ArbeitsumfangReihen-
folgeBauteil Anz. Bemerkungen
FEDERBEIN DEMONTIEREN
WARNUNGDas Fahrzeug sicher abstützen, damit es nichtumfallen kann. Vorbereitungsarbeiten Das Motorrad am Motor aufbokken und in
gerader Stellung halten.
Sitzbank und Haltegummi Siehe unter “SITZBANK, KRAFTSTOFFTANK UND
SEITENABDECKUNGEN” in KAPITEL 4.
Schalldämpfer Siehe unter “AUSPUFFKRÜMMER UND SCHALL-
DÄMPFER” in KAPITEL 4.
1 Schlauchschelle (Vergasereinlaß-
Anschluß)1 Lediglich lockern.
2 Rahmenheck 1
3 Schraube (Federbein und Umlenkhebel) 1 Die Schwinge festhalten.
4 Schraube (Federbein und Rahmen) 1
5 Federbein 1
6 Sicherungsmutter 1 Lediglich lockern.
7 Federvorspannring 1 Lediglich lockern.
8 Federführung unten 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 la pièce QtéRemarques
DEPOSE DE L’AMORTISSEUR ARRIERE
AVERTISSEMENTBien caler la moto afin qu’elle ne risque pas de bascu-ler. Préparation à la dépose Caler la moto en plaçant un support adéquat
sous le moteur.
Selle et bande de fixation Se reporter à la section “SELLE, RESERVOIR DE CAR-
BURANT ET CACHES LATERAUX” au CHAPITRE 4.
Silencieux Se reporter à la section “TUBE D’ECHAPPEMENT ET
SILENCIEUX” au CHAPITRE 4.
1 Collier à pince (conduit d’admission d’air) 1 Desserrer uniquement.
2 Cadre arrière 1
3 Boulon (amortisseur arrière - bras relais) 1 Maintenir 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
Estensione della rimozione:1 Rimozione ammortizzatore posteriore2 Disassemblaggio ammortizzatore posteriore
Estensione della rimozione Ordine Denominazione QuantitàOsservazioni
RIMOZIONE AMMORTIZZATORE
POSTERIORE
AVVERTENZASostenere saldamente il mezzo in modo che non vi siail rischio che si rovesci. Preparazione per la rimozione Sostenere il mezzo ponendo un idoneo caval-
letto sotto il motore.
Sella e fascia di fissaggio Fare riferimento al paragrafo “SELLA, SERBATOIO
CARBURANTE E FIANCHETTI” nel CAPITOLO 4.
Silenziatore Fare riferimento al paragrafo “TUBO DI SCARICO E
SILENZIATORE” nel CAPITOLO 4.
1 Morsetto (giunto del filtro dell’aria) 1 Allentare soltanto.
2 Telaio posteriore 1
3 Bullone (ammortizzatore posteriore-braccio di
rinvio)1 Sollevare il forcellone oscillante.
4 Bullone (ammortizzatore posteriore-telaio) 1
5 Ammortizzatore posteriore 1
6 Controdado 1 Allentare soltanto.
7 Dispositivo di regolazione 1 Allentare soltanto.
8 Guida molla inferiore 1
1
2
AMORTISSEUR ARRIERE
FEDERBEIN
AMMORTIZZATORE POSTERIORE

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CHASREAR SHOCK ABSORBER
Extent of removal Order Part name Q’ty Remarks
9 Upper spring guide 1
10 Spring (rear shock absorber) 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
2

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CHAS
HANDLING NOTE
WARNING
This rear shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of
explosion, read and understand the follow-
ing information before handling the shock
absorber.
The manufacturer can not be held respon-
sible for property damage or personal
injury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the rear shock absorber
into an open flame or other high heat.
The rear shock absorber may explode as
a result of nitrogen gas expansion and/
or damage to the hose.
3. Be careful not to damage any part of the
gas tank. A damaged gas tank will impair
the damping performance or cause a
malfunction.
4. Take care not to scratch the contact sur-
face of the piston rod with the cylinder;
or oil could leak out.
5. Never attempt to remove the plug at the
bottom of the nitrogen gas tank. It is
very dangerous to remove the plug.
6. When scrapping the rear shock
absorber, follow the instructions on dis-
posal.
NOTES ON DISPOSAL (YAMAHA DEALERS
ONLY)
Before disposing the rear shock absorber, be
sure to extract the nitrogen gas from valve 1.
Wear eye protection to prevent eye damage
from escaping gas and/or metal chips.
WARNING
To dispose of a damaged or worn-out rear
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
REAR SHOCK ABSORBER

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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.
Bearing 5
Free play exists/unsmooth revolution/rust
→ Replace.
REAR SHOCK ABSORBER

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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

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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.
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.
Spring length (installed)
a:
Standard lengthExtent of
adjustment
250.5 mm (9.86 in)
* 248.5 mm (9.78 in)240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)

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CHASREAR SHOCK ABSORBER
2. Install:
Bushing 1
Collar 2
Dust seal 3
NOTE:
Apply the molybdenum disulfide grease on
the bearing.
Apply the lithium soap base grease on the
bushing, collars and dust seals.
Install the dust seals with their lips facing out-
ward.
3. Install:
Rear shock absorber
4. Install:
Bolt (rear shock absorber-frame) 1
Nut (rear shock absorber-frame) 2
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.
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 (upper)] 2
Bolt [rear frame (lower)] 3
T R..32 Nm (3.2 m · kg, 23 ft · lb)
T R..29 Nm (2.9 m · kg, 21 ft · lb)
7. Tighten:
Screw (air filter joint) 1
T R..3 Nm (0.3 m · kg, 2.2 ft · lb)