2004 YAMAHA YZ450F oil

6. GASOLINE CAN CAUSE INJURY.
If you should swallow some gasoline,
inhale excess gasoline vapors, or
allow any gasoline to get into your
eyes, contact a doctor immediately. If
any gasoline spills onto your skin or
clothing, immediately wash skin areas
with soap and water, and change your
clothes.
7. ONLY OPERATE THE MACHINE IN AN
AREA WITH ADEQUATE VENTILA-
TION.
Never start the engine or let it run for
any length of time in an enclosed area.
Exhaust fumes are poisonous. These
fumes contain carbon monoxide,
which by itself is odorless and color-
less. Carbon monoxide is a dangerous
gas which can cause unconscious-
ness or can be lethal.
8. PARK THE MACHINE CAREFULLY;
TURN OFF THE ENGINE.
Always turn off the engine if you are
going to leave the machine. Do not
park the machine on a slope or soft
ground as it may fall over.
9. THE ENGINE, EXHAUST PIPE, MUF-
FLER, AND OIL TANK WILL BE VERY
HOT AFTER THE ENGINE HAS BEEN
RUN.
Be careful not to touch them or to
allow any clothing item to contact
them during inspection or repair.
10. PROPERLY SECURE THE MACHINE
BEFORE TRANSPORTING IT.
When transporting the machine in
another vehicle, always be sure it is
properly secured and in an upright
position and that the fuel cock is in
the “OFF” position. Otherwise, fuel
may leak out of the carburetor or fuel
tank.

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols
1
to
7
are designed as
thumb tabs to indicate the chapter’s number
and content.
1
General information
2
Specifications
3
Regular inspection and adjustments
4
Engine
5
Chassis
6
Electrical
7
Tuning
Illustrated symbols
8
to
D
are used to identify
the specifications appearing in the text.
8
With engine mounted
9
Special tool
0
Filling fluid
A
Lubricant
B
Tightening
C
Specified value, Service limit
D
Resistance (
Ω
), Voltage (V), Electric current (A)
Illustrated symbols
E
to
H
in the exploded
diagrams indicate grade of lubricant and loca-
tion of lubrication point.
E
Apply engine oil
F
Apply molybdenum disulfide oil
G
Apply lightweight lithium-soap base grease
H
Apply molybdenum disulfide grease
Illustrated symbols
I
to
J
in the exploded
diagrams indicate where to apply a locking
agent and where to install new parts.
IApply locking agent (LOCTITE®)
JUse new one 12
34
56
78
90
AB
CD
EF
GH
IJ
GEN
INFOSPEC
INSP
ADJENG
CHAS–+ELEC
TUN
T R..
EM
BM
New

CHAPTER 4
ENGINE
SEAT, FUEL TANK
AND SIDE COVERS
..................................4-1
EXHAUST PIPE AND SILENCER
.............4-3
RADIATOR
................................................4-5
CARBURETOR
..........................................4-8
CAMSHAFTS
...........................................4-21
CYLINDER HEAD
....................................4-29
VALVES AND VALVE SPRINGS
............4-33
CYLINDER AND PISTON
........................4-42
CLUTCH
...................................................4-48
OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT)
..............4-55
BALANCER
.............................................4-62
OIL PUMP
................................................4-65
KICK AXLE AND SHIFT SHAFT
.............4-69
CDI MAGNETO
........................................4-76
ENGINE REMOVAL
.................................4-80
CRANKCASE AND CRANKSHAFT
........4-85
TRANSMISSION, SHIFT CAM
AND SHIFT FORK
...................................4-94
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL
.......5-1
FRONT BRAKE AND REAR BRAKE
.....5-10
FRONT FORK
..........................................5-26
HANDLEBAR
...........................................5-39
STEERING
...............................................5-45
SWINGARM
.............................................5-50
REAR SHOCK ABSORBER
....................5-58

GEN
INFO

1 - 1
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1
Clutch lever
2
Hot starter lever
3
Front brake lever
4
Throttle grip
5
Radiator cap
6
Fuel tank cap
7
“ENGINE STOP” button
8
Kick starter
9
Fuel tank
0
Radiator
A
Coolant drain bolt
B
Rear brake pedal
C
Valve joint
D
Fuel cock
E
Cold starter knob
F
Drive chain
G
Air cleaner
H
Shift pedal
IOil dipstick
JFront fork
NOTE:
The machine you have purchased may differ
slightly from those shown in the following.
Designs and specifications are subject to
change without notice.

1 - 4
GEN
INFO
IMPORTANT INFORMATION
EC132000
ALL REPLACEMENT PARTS
1. We recommend to use Yamaha genuine
parts for all replacements. Use oil and/or
grease recommended by Yamaha for
assembly and adjustment.
EC133000
GASKETS, OIL SEALS AND O-RINGS
1. All gaskets, oil seals, and O-rings should
be replaced when an engine is over-
hauled. All gasket surfaces, oil seal lips,
and O-rings must be cleaned.
2. Properly oil all mating parts and bearings
during reassembly. Apply grease to the
oil seal lips.
EC134000
LOCK WASHERS/PLATES AND COTTER
PINS
1. All lock washers/plates 1 and cotter pins
must be replaced when they are
removed. Lock tab(s) should be bent
along the bolt or nut flat(s) after the bolt
or nut has been properly tightened.
EC135001
BEARINGS AND OIL SEALS
1. Install the bearing(s) 1 and oil seal(s) 2
with their manufacturer’s marks or num-
bers facing outward. (In other words, the
stamped letters must be on the side
exposed to view.) When installing oil
seal(s), apply a light coating of light-
weight lithium base grease to the seal
lip(s). Oil the bearings liberally when
installing.
CAUTION:
Do not use compressed air to spin the
bearings dry. This causes damage to the
bearing surfaces.

GEN
INFO
1 - 8
SPECIAL TOOLS
YU-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-01442, 90890-01442 Fork seal driver
This tool is used when install the fork oil seal.YM-01442 90890-01442
YM-01494, 90890-01494 Damper rod holder
Use this tool to remove and install the damper rod.YM-01494 90890-01494
YU-3112-C, 90890-03112 Yamaha pocket tester
Use this tool to inspect the coil resistance, output
voltage and amperage.YU-3112-C 90890-03112
YM-33277-A, 90890-03141 Timing light
This tool is necessary for checking ignition timing.YM-33277-A 90890-03141
YM-4019, 90890-04019 Valve spring compressor
This tool is needed to remove and install the valve
assemblies.YM-4019 90890-04019
YM-91042, 90890-04086 Clutch holding tool
This tool is used to hold the clutch when removing or
installing the clutch boss securing nut.YM-91042 90890-04086
YM-4116, 90890-04116
YM-4097, 90890-04097Valve guide remover
Intake 4.5 mm (0.18 in)
Exhaust 5.0 mm (0.20 in)
This tool is needed to remove and install the valve
guide.YM-4116
YM-409790890-04116
90890-04097
YM-4117, 90890-04117
YM-4098, 90890-04098Valve guide installer
Intake
Exhaust
This tool is needed to install the valve guide.YM-4117
YM-409890890-04117
90890-04098
Part number Tool name/How to use Illustration

GEN
INFO
OUTILS SPECIAUX
Les outils spéciaux appropriés sont indispensables pour pouvoir effectuer un assemblage et une mise au point
complets et précis. L’utilisation des outils spéciaux corrects permettra d’éviter les endommagements dus à
l’emploi d’outils impropres et aux techniques improvisées entraînées par ceux-ci. La forme et le numéro de
pièce des outils spéciaux diffèrent selon les pays. Voilà pourquoi il y a parfois deux versions d’un outil. La
liste suivante permet d’éviter toute erreur lors de la commande de pièces.
N.B.:
Pour les E.-U. et le Canada, utiliser les numéros de pièce qui commencent par “YM-”, “YU-” ou “ACC-”.
Pour les autres pays utiliser les numéros de pièce qui commencent par “90890-”.
Numéros de pièce Nom et usage de l’outil Illustration
YU-1135-A, 90890-01135 Outil de séparation de carter
Cet outil permet de séparer le vilebrequin des demi-car-
ters.YU-1135-A 90890-01135
YU-1235, 90890-01235 Outil de maintien de rotor
Cet outil est utilisé pour le desserrage ou le serrage du
boulon de fixation de volant magnétique.YU-1235 90890-01235
YU-3097, 90890-01252
YU-1256Comparateur et support
Support
Ces outils permettent de mesurer le faux-rond ou la défor-
mation de pièces.YU-3097
YU-125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YU-91044, 90890-04081
YU-90063, 90890-01278Outil de montage du vilebrequin
Pot de montage du vilebrequin
Boulon de montage du vilebrequin
Entretoise (installation de vilebrequin)
Adaptateur (M12)
Ces outils sont utilisé pour la montage du vilebrequin.YU-90050
YU-90063
YU-9104490890-01274
90890-01275
90890-01278
90890-04081
YU-1304, 90890-01304 Extracteur d’axe de piston
Cet outil est utilisé pour extraire les axes de piston.YU-1304 90890-01304
YU-24460-01, 90890-01325
YU-33984, 90890-01352Testeur de bouchon de radiateur
Adaptateur
Ces outils sont utilisés pour le contrôle du système de
refroidissement.YU-24460-01
YU-3398490890-01325
90890-01352
YM-1189, 90890-01189 Extracteur du volant
Cet outil doit être utilisé pour la dépose du volant magnéti-
que.YM-1189 90890-01189
OUTILS SPECIAUX
1 - 7

GEN
INFO
1 - 18
TORQUE-CHECK POINTS
TORQUE-CHECK POINTS
NOTE:
Concerning the tightening torque, refer to
“MAINTENANCE SPECIFICATIONS” section
in the CHAPTER 2.
Frame to rear frame
Fuel tank to frame
Silencer to rear frame
Frame to engine
Engine bracket to engine
Engine bracket to frame
Steering shaft to frame
Steering shaft to handle crown
Handle crown to handlebar
Front fork to handle crown
Front fork to under bracket
Assembly of links
Link to frame
Link to shock absorber
Link to swingarm
Shock absorber to frame
Tightening of pivot shaft
Tightening of front axle
Tightening of axle holder
Tightening of rear axle
Wheel to sprocket
Caliper to front fork
Brake disc to wheel
Tightening of union bolt
Master cylinder to handlebar
Tightening of air bleeder
Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Master cylinder to frame
Tightening of air bleeder
Fuel tank to fuel cock
Tightening of oil hose clamp Frame construction
Combined seat and tank
Exhaust system
Engine mounting
Steering Steering shaft to
handlebar
Suspension Front Steering shaft to front
fork
Rear For link type
Rear Installation of shock
absorber
Rear Installation of swing-
arm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel system
Lubrication system