maintenance YAMAHA YZ250F 2004 Owner's Manual

3 - 4
INSP
ADJ
PRE-OPERATION INSPECTION AND MAINTENANCE
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
CoolantCheck that coolant is filled up to the radiator cap.
Check the cooling system for leakage.P.3-5 ~ 9
FuelCheck that a fresh gasoline is filled in the fuel tank. Check the
fuel line for leakage.P.1-13
Engine oilCheck that the oil level is correct. Check the crankcase and
frame oil line for leakage.P.3-13 ~ 17
Gear shifter and clutchCheck that gears can be shifted correctly in order and that the
clutch operates smoothly.P.3-9
Throttle grip/HousingCheck that the throttle grip operation and free play are correctly
adjusted. Lubricate the throttle grip and housing, if necessary.P.3-10
Brakes Check the play of front brake and effect of front and rear brake. P.3-24 ~ 30
Drive chainCheck drive chain slack and alignment. Check that the drive
chain is lubricated properly.P.3-31 ~ 33
WheelsCheck for excessive wear and tire pressure. Check for loose
spokes and have no excessive play.P.3-41 ~ 42
SteeringCheck that the handlebar can be turned smoothly and have no
excessive play.P.3-42 ~ 43
Front forks and rear shock
absorberCheck that they operate smoothly and there is no oil leakage. P.3-33 ~ 40
Cables (wires)Check that the clutch and throttle cables move smoothly. Check
that they are not caught when the handlebars are turned or
when the front forks travel up and down.—
Exhaust pipeCheck that the exhaust pipe is tightly mounted and has no
cracks.P.4-3 ~ 4
Rear wheel sprocket Check that the rear wheel sprocket tightening bolt is not loose. P.3-31
Lubrication Check for smooth operation. Lubricate if necessary. P.3-44
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P.1-18
Lead connectorsCheck that the CDI magneto, CDI unit, and ignition coil are con-
nected tightly.P.1-6
SettingsIs the machine set suitably for the condition of the racing course
and weather or by taking into account the results of test runs
before racing? Are inspection and maintenance completely
done?P.7-1 ~ 22

3 - 11
INSP
ADJHOT STARTER LEVER ADJUSTMENT/
AIR FILTER CLEANING
HOT STARTER LEVER ADJUSTMENT
1. Check:
Hot starter lever free play a
Out of specification → Adjust.
2. Adjust:
Hot starter lever free play
NOTE:
After adjustment, check proper operation of
hot starter.
Hot starter lever free play a:
3 ~ 6 mm (0.12 ~ 0.24 in)
Hot starter lever free play adjustment
steps:
Loosen the locknut 1.
Turn the adjuster 2 until free play a is
within the specified limits.
Tighten the locknut.
AIR FILTER CLEANING
NOTE:
Proper air filter maintenance is the biggest key
to preventing premature engine wear and
damage.
CAUTION:
Never run the engine without the air filter
element in place; this would allow dirt and
dust to enter the engine and cause rapid
wear and possible engine damage.
1. Remove:
Seat
Fitting bolt 1
Washer 2
Air filter element 3
Air filter guide 4

5 - 52
CHASSWINGARM
EC573000
REMOVAL POINTS
EC573200
Bearing
1. Remove:
Bearing 1
NOTE:
Remove the bearing by pressing its outer race.
INSPECTION
Wash the bearings, bushings, collars, and cov-
ers in a solvent.
Swingarm
1. Inspect:
Bearing 1
Bushing 2
Free play exists/unsmooth revolution/
rust → Replace bearing and bushing as
a set.
2. Inspect:
Oil seal 3
Damage → Replace.
EC574210
Relay arm
1. Inspect:
Bearing (polylube bearing) 1
Collar 2
Free play exists/unsmooth revolution/rust
→ Replace bearing and collar as a set.
2. Inspect:
Bearing (polylube bearing) 1
Loss of solid lubrication → Replace.
Oil seal 3
Damage → Replace.
NOTE:
Polylube bearings, with solid lubrication, have
been adopted with the intent to make the nee-
dle bearings, used in this model, maintenance
free. With polylube bearings, no grease nipple
and regular lubrication is necessary. However,
grease should be applied to all oil seals and
collars when removed or installed.

5 - 52
CHAS
BRAS OSCILLANT
SCHWINGE
FORCELLONE OSCILLANTE
AUSBAU
Lager
1. Demontieren:
Lager 1
HINWEIS:
Das Lager am äußeren Laufring ein-
pressen.
PRÜFUNG
Die Lager, Buchsen, Hülsen und
Anlaufscheiben in Lösungsmittel
waschen.
Schwinge
1. Kontrollieren:
Lager 1
Buchse 2
Spiel/Schwergängigkeit/
Rost → Lager und Buchse
im Satz erneuern.
2. Kontrollieren:
Dichtring 3
Beschädigung → Erneuern.
Umlenkhebel
1. Kontrollieren:
Lager (Polylube-Lager) 1
Hülse 2
Spiel/Schwergängigkeit/
Rost → Lager und Hülse im
Satz erneuern.
2. Kontrollieren:
Lager (Polylube-Lager) 1
Verlust der Trockenschmie-
rung → Erneuern.
Dichtring 3
Beschädigung → Erneuern.
HINWEIS:
Polylube-Lager mit Trockenschmie-
rung werden eingesetzt, um die in
diesem Modell verwendeten Nadella-
ger wartungsfrei zu machen. Bei Po-
lylube-Lagern gibt es keine Schmier-
nippel, und regelmäßige Schmierung
ist nicht erforderlich. Es sollte aber
beim Ausbau oder Einbau Fett auf
alle Ölabdichtungen und Hülsen auf-
getragen werden. POINTS DE DEPOSE
Roulement
1. Déposer:
Roulement 1
N.B.:
Retirer le roulement en appuyant sur la
cage extérieure.
CONTROLE
Laver les roulements, les bagues, les col-
lerettes et les caches dans un dissolvant.
Bras oscillant
1. Contrôler:
Roulement 1
Bague 2
Jeu/rotation irrégulière/rouille
→ Remplacer à la fois le roule-
ment et la bague.
2. Contrôler:
Bague d’étanchéité 3
Endommagement → Changer.
Bras de relais
1. Contrôler:
Roulement (roulement poly-
lube) 1
Collerette 2
Jeu/rotation irrégulière/rouille
→ Remplacer à la fois le roule-
ment et la collerette.
2. Contrôler:
Roulement (roulement poly-
lube) 1
Perte de lubrification solide →
Remplacer.
Bague d’étanchéité 3
Endommagement → Rempla-
cer.
N.B.:
Les roulements polylube, à lubrification
solide, ont été adoptés pour éliminer la
maintenance des roulements à aiguilles,
utilisés sur ce modèle. Les roulements
polylube rendent le graissage par les
graisseurs et le graissage ordinaire inuti-
les. Tous les colliers et joints à huile doi-
vent néanmoins être graissés lorsqu’ils
sont retirés ou installés. PUNTI DI RIMOZIONE
Cuscinetto
1. Rimuovere:
Cuscinetto 1
NOTA:
Rimuovere il cuscinetto premendo
sull’anello esterno.
ISPEZIONE
Lavare i cuscinetti, le boccole, i collarini
e i coperchi con un solvente.
Forcellone oscillante
1. Ispezionare:
Cuscinetto 1
Boccola 2
Gioco/movimento non agevole/
ruggine → Sostituire in blocco
il cuscinetto e la boccola.
2. Ispezionare:
Paraolio 3
Danni → Sostituire.
Leva di rinvio
1. Ispezionare:
Cuscinetto
(cuscinetto polylube) 1
Collarino 2
Gioco/movimento non agevole/
ruggine → Sostituire in blocco
il cuscinetto e il collarino.
2. Ispezionare:
Cuscinetto
(cuscinetto polylube) 1
Perdita di lubrificazione solida
→ Sostituire.
Paraolio 3
Danni → Sostituire.
NOTA:
I cuscinetti polylube, con lubrificazione
solida, sono stati adottati in modo che i
cuscinetti a spillo usati in questo modello
non necessitino di manutenzione. Con
cuscinetti polylube, non è necessario un
ingrassatore o una lubrificazione perio-
dica. Tuttavia, si deve applicare grasso a
tutti i paraolio e collarini quando ven-
gono rimossi o installati.

5 - 53
CHASSWINGARM
EC574310
Connecting rod
1. Inspect:
Bearing (polylube bearing) 1
Collar 2
Free play exists/unsmooth revolution/rust
→ Replace bearing and collar as a set.
2. Inspect:
Bearing (polylube bearing) 1
Loss of solid lubrication → Replace.
Oil seal 3
Damage → Replace.
NOTE:
Polylube bearings, with solid lubrication, have
been adopted with the intent to make the nee-
dle bearings, used in this model, maintenance
free. With polylube bearings, no grease nipple
and regular lubrication is necessary. However,
grease should be applied to all oil seals and
collars when removed or installed.
EC575000
ASSEMBLY AND INSTALLATION
EC575201
Bearing and oil seal
1. Install:
Bearing 1
Oil seal 2
To swingarm.
NOTE:
Apply the molybdenum disulfide grease on
the bearing when installing.
Install the bearing by pressing it on the side
having the manufacture’s marks or numbers.
First install the outer and then the inner bear-
ings to a specified depth from inside.
Installed depth of bearings:
Outer a: Zero mm (Zero in)
Inner b: 8.5 mm (0.33 in)

5 - 53
CHAS
BRAS OSCILLANT
SCHWINGE
FORCELLONE OSCILLANTE
Übertragungshebel
1. Kontrollieren:
Lager (Polylube-Lager) 1
Hülse 2
Spiel/Schwergängigkeit/
Rost → Lager und Hülse im
Satz erneuern.
2. Kontrollieren:
Lager (Polylube-Lager) 1
Verlust der Trockenschmie-
rung → Erneuern.
Dichtring 3
Beschädigung → Erneuern.
HINWEIS:
Polylube-Lager mit Trockenschmie-
rung werden eingesetzt, um die in
diesem Modell verwendeten Nadella-
ger wartungsfrei zu machen. Bei Po-
lylube-Lagern gibt es keine Schmier-
nippel, und regelmäßige Schmierung
ist nicht erforderlich. Es sollte aber
beim Ausbau oder Einbau Fett auf
alle Ölabdichtungen und Hülsen auf-
getragen werden.
ZUSAMMENBAU UND MONTAGE
Lager und Dichtringe
1. Montieren:
Lager 1
Dichtringe 2
(an der Schwinge)
HINWEIS:
Molybdändisulfidfett auf die einge-
bauten Lager auftragen.
Die Lager zum Einbauen auf der
Seite mit den Herstellerangaben
einpressen.
Zuerst die äußeren, dann die inne-
ren Lager vorschriftsmäßig eintrei-
ben.
Lager-Einbautiefe:
Außen a: 0 mm (0 in)
Innen b: 8,5 mm
(0,33 in)
Bielle
1. Contrôler:
Roulement (roulement poly-
lube) 1
Collerette 2
Jeu/rotation irrégulière/rouille
→ Remplacer à la fois le roule-
ment et la collerette.
2. Contrôler:
Roulement (roulement poly-
lube) 1
Perte de lubrification solide →
Remplacer.
Bague d’étanchéité 3
Endommagement → Rempla-
cer.
N.B.:
Les roulements polylube, à lubrification
solide, ont été adoptés pour éliminer la
maintenance des roulements à aiguilles,
utilisés sur ce modèle. Les roulements
polylube rendent le graissage par les
graisseurs et le graissage ordinaire inuti-
les. Tous les colliers et joints à huile doi-
vent néanmoins être graissés lorsqu’ils
sont retirés ou installés.
REMONTAGE ET MONTAGE
Roulement et bague d’étanchéité
1. Monter:
Roulement 1
Bague d’étanchéité 2
Sur le bras oscillant.
N.B.:
Appliquer une graisse au bisulfure de
molybdène sur le roulement lors de la
repose.
Installer le roulement en appuyant sur
le côté où figurent les repères ou
numéros du fabricant.
Mettre d’abord les roulements exter-
nes puis les roulements internes en
place, à la profondeur spécifiée.
Protondeur d’installation
des roulements:
Externe a: 0 mm (0 in)
Interne b: 8,5 mm
(0,33 in)
Biella
1. Ispezionare:
Cuscinetto
(cuscinetto polylube) 1
Collarino 2
Gioco/movimento non agevole/
ruggine → Sostituire in blocco
il cuscinetto e il collarino.
2. Ispezionare:
Cuscinetto
(cuscinetto polylube) 1
Perdita di lubrificazione solida
→ Sostituire.
Paraolio 3
Danni → Sostituire.
NOTA:
I cuscinetti polylube, con lubrificazione
solida, sono stati adottati in modo che i
cuscinetti a spillo usati in questo modello
non necessitino di manutenzione. Con
cuscinetti polylube, non è necessario un
ingrassatore o una lubrificazione perio-
dica. Tuttavia, si deve applicare grasso a
tutti i paraolio e collarini quando ven-
gono rimossi o installati.
MONTAGGIO ED INSTALLA-
ZIONE
Cuscinetto e paraolio
1. Installare:
Cuscinetto 1
Paraolio 2
Sul forcellone oscillante.
NOTA:
Applicare grasso al disolfuro di molib-
deno sul cuscinetto durante l’installa-
zione.
Installare il cuscinetto premendo sul
lato recante il simbolo o il numero di
produzione.
Installare innanzitutto il cuscinetto
esterno quindi quello interno fino alla
profondità specificata dall’interno.
Profondità installata dei
cuscinetti:
Esterno a: Zero mm
(Zero in)
Interno b: 8,5 mm
(0,33 in)