maintenance YAMAHA YZ450F 2003 Owner's Manual

3 - 3
INSP
ADJ

MAINTENANCE INTERVALS
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube
●

●
Lithium base grease
REAR SHOCK ABSORBER
Inspect and adjust
Lube
Retighten
●

●

●

●

●

(After
rain ride)
● Molybdenum disulfide
grease
CHAIN GUARD AND ROLLERS
Inspect
● ●
SWINGARM
Inspect, lube and retighten
● ● Molybdenum disulfide
grease
RELAY ARM, CONNECTING ROD
Inspect, lube and retighten
● ● Molybdenum disulfide
grease
STEERING HEAD
Inspect free play and retighten
Clean and lube
Replace bearing
● ●
●
● Lithium base grease
TIRE, WHEELS
Inspect air pressure, wheel run-out,
tire wear and spoke looseness
Retighten sprocket bolt
Inspect bearings
Replace bearings
Lubricate
●
●
●
●
●
●
●
Lithium base grease
THROTTLE, CONTROL CABLE
Check routing and connection
Lubricate
●
●
●
● Yamaha cable lube or
SAE 10W-30 motor oil
HOT STARTER, CLUTCH LEVER
Inspect free play
●
ItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks

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 filler 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.1-17
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
ChainCheck chain slack and alignment. Check that the chain is lubri-
cated 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.—
Muffler Check that the muffler is tightly mounted and has no cracks.—
Sprocket Check that the driven 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.1-22
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 ~ 21

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.
EC35G040
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
Filter guide 4

5 - 52
CHASSWINGARM
EC573000
REMOVAL POINTS
EC573200
Bearing
1. Remove:
Bearing 1
NOTE:
Install the bearing by pressing its outer race.
EC574010
INSPECTION
Wash the bearings, bushes, collars, and cov-
ers in a solvent.
EC574111
Swingarm
1. Inspect:
Bearing 1
Bush 2
Free play exists/unsmooth revolution/
rust → Replace bearing and bush 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
AUSBAU
Lager
1. Demontieren:
Lager 1
HINWEIS:
Das Lager am äußeren Laufring einpressen.
PRÜFUNG
Die Lager, Buchsen, Hülsen und Anlaufschei-
ben 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 Trockenschmierung →
Erneuern.
Dichtring 3
Beschädigung → Erneuern.
HINWEIS:
Polylube-Lager mit Trockenschmierung wer-
den eingesetzt, um die in diesem Modell ver-
wendeten Nadellager wartungsfrei zu machen.
Bei Polylube-Lagern gibt es keine Schmiernip-
pel, und regelmäßige Schmierung ist nicht
erforderlich. Es sollte aber beim Ausbau oder
Einbau Fett auf alle Ölabdichtungen und Hül-
sen aufgetragen werden. POINTS DE DEPOSE
Roulement
1. Déposer:
Roulement 1
N.B.:
Monter le roulement en appuyant sur la cage exté-
rieure.
CONTROLE
Laver les roulements, les bagues, les collerettes et
les caches dans un dissolvant.
Bras oscillant
1. Contrôler:
Roulement 1
Bague 2
Jeu/rotation irrégulière/rouille → Changer à
la fois le roulement et la bague.
2. Contrôler:
Bague d’étanchéité 3
Endommagement → Changer.
Bras de relais
1. Contrôler:
Roulement (roulement polylube) 1
Collerette 2
Jeu/rotation irrégulière/rouille → Changer à
la fois le roulement et la collerette.
2. Contrôler:
Roulement (roulement polylube) 1
Perte de lubrification solide → Remplacer.
Bague d’étanchéité 3
Endommagement → Changer.
N.B.:
Les roulements polylube, à lubrification solide, ont
été adoptés pour éliminer la maintenance des roule-
ments à aiguilles, utilisés sur ce modèle. Les roule-
ments polylube rendent le graissage par les
graisseurs et le graissage ordinaire inutiles. Tous
les colliers et joints à huile doivent néanmoins être
graissés lorsqu’ils sont retirés ou installés.

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
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 Trockenschmierung →
Erneuern.
Dichtring 3
Beschädigung → Erneuern.
HINWEIS:
Polylube-Lager mit Trockenschmierung wer-
den eingesetzt, um die in diesem Modell ver-
wendeten Nadellager wartungsfrei zu machen.
Bei Polylube-Lagern gibt es keine Schmiernip-
pel, und regelmäßige Schmierung ist nicht
erforderlich. Es sollte aber beim Ausbau oder
Einbau Fett auf alle Ölabdichtungen und Hül-
sen aufgetragen werden.
ZUSAMMENBAU UND MONTAGE
Lager und Dichtringe
1. Montieren:
Lager 1
Dichtringe 2
(an der Schwinge)
HINWEIS:
Molybdändisulfidfett auf die eingebauten La-
ger auftragen.
Die Lager zum Einbauen auf der Seite mit
den Herstellerangaben einpressen.
Zuerst die äußeren, dann die inneren Lager
vorschriftsmäßig eintreiben.
Lager-Einbautiefe
Außen a: 0 mm
Innen b: 8,5 mm
Bielle
1. Contrôler:
Roulement (roulement polylube) 1
Collerette 2
Jeu/rotation irrégulière/rouille → Changer à
la fois le roulement et la collerette.
2. Contrôler:
Roulement (roulement polylube) 1
Perte de lubrification solide → Remplacer.
Bague d’étanchéité 3
Endommagement → Changer.
N.B.:
Les roulements polylube, à lubrification solide, ont
été adoptés pour éliminer la maintenance des roule-
ments à aiguilles, utilisés sur ce modèle. Les roule-
ments polylube rendent le graissage par les
graisseurs et le graissage ordinaire inutiles. Tous
les colliers et joints à huile doivent 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 externes puis les
roulements internes en place, à la protondeur spé-
cifiée.
Protondeur d’installation des roule-
ments:
Externe a: 0 mm (0 in)
Interne b: 8,5 mm (0,33 in)