engine YAMAHA YZ450F 2005 Owners Manual

IMPORTANT NOTICE
THIS MACHINE IS DESIGNED STRICTLY
FOR COMPETITION USE, ONLY ON A
CLOSED COURSE. It is illegal for this
machine to be operated on any public street,
road, or highway. Off-road use on public lands
may also be illegal. Please check local regula-
tions before riding.
1. THIS MACHINE IS TO BE OPERATED
BY AN EXPERIENCED RIDER ONLY.
Do not attempt to operate this
machine at maximum power until you
are totally familiar with its character-
istics.
2. THIS MACHINE IS DESIGNED TO BE
RIDDEN BY THE OPERATOR ONLY.
Do not carry passengers on this
machine.
3. ALWAYS WEAR PROTECTIVE
APPAREL.
When operating this machine, always
wear an approved helmet with gog-
gles or a face shield. Also wear heavy
boots, gloves, and protective cloth-
ing. Always wear proper fitting cloth-
ing that will not be caught in any of
the moving parts or controls of the
machine.
4. ALWAYS MAINTAIN YOUR MACHINE
IN PROPER WORKING ORDER.
For safety and reliability, the machine
must be properly maintained. Always
perform the pre-operation checks
indicated in this manual. Correcting a
mechanical problem before you ride
may prevent an accident.
5. GASOLINE IS HIGHLY FLAMMABLE.
Always turn off the engine while refu-
eling. Take care to not spill any gaso-
line on the engine or exhaust system.
Never refuel in the vicinity of an open
flame, or while smoking.
SAFETY INFORMATION

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 danger-
ous gas which can cause
unconsciousness 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.

EC080000
HOW TO USE
THIS MANUAL
EC081000
PARTICULARLY IMPORTANT
INFORMATION
The Safety Alert Symbol means ATTENTION!
BECOME ALERT! YOUR SAFETY IS
INVOLVED!
Failure to follow WARNING instructions could
result in severe injury or death to the machine
operator, a bystander, or a person inspecting
or repairing the machine.
A CAUTION indicates special precautions that
must be taken to avoid damage to the
machine.
NOTE:
A NOTE provides key information to make pro-
cedures easier or clearer.
WA R N I N G
CAUTION:
EC082000
FINDING THE REQUIRED PAGE
1. This manual consists of seven chapters;
“General Information”, “Specifications”,
“Regular inspection and adjustments”,
“Engine”, “Chassis”, “Electrical” and “Tun-
ing”.
2. The table of contents is at the beginning of
the manual. Look over the general layout of
the book before finding then required chap-
ter and item.
Bend the book at its edge, as shown, to
find the required fore edge symbol mark
and go to a page for required item and
description.

ILLUSTRATED SYMBOLS
(Refer to the illustration)
Illustrated symbols 1 to 7 are designed as
thumb tabs to indicate the chapter’s number
and content.
1General information
2Specifications
3Regular inspection and adjustments
4Engine
5Chassis
6Electrical
7Tuning
Illustrated symbols 8 to D are used to identify
the specifications appearing in the text.
8With engine mounted
9Special tool
0Filling fluid
ALubricant
BTightening
CSpecified value, Service limit
DResistance (
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.
EApply engine oil
FApply molybdenum disulfide oil
GApply lightweight lithium-soap base grease
HApply 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
ADJ
ENG
CHAS–+ELEC
TUN
T R..
EM
BM
New

EC090000
INDEX
GENERAL
INFORMATION
SPECIFICATIONS
REGULAR
INSPECTION AND
ADJUSTMENTS
ENGINE
CHASSIS
ELECTRICAL
TUNING

EC0A0000
CONTENTS
CHAPTER 1
GENERAL INFORMATION
DESCRIPTION
...........................................1-1
MACHINE IDENTIFICATION
.....................1-2
IMPORTANT INFORMATION
....................1-3
CHECKING OF CONNECTION
.................1-6
SPECIAL TOOLS
......................................1-7
CONTROL FUNCTIONS
..........................1-10
FUEL
........................................................1-13
STARTING AND BREAK-IN
....................1-14
TORQUE-CHECK POINTS
......................1-18
CLEANING AND STORAGE
...................1-19
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICATIONS
...................2-1
MAINTENANCE SPECIFICATIONS
..........2-4
GENERAL TORQUE
SPECIFICATIONS
...................................2-18
DEFINITION OF UNITS
...........................2-18
LUBRICATION DIAGRAMS
....................2-19
CABLE ROUTING DIAGRAM
.................2-21
CHAPTER 3
REGULAR INSPECTION
AND ADJUSTMENTS
MAINTENANCE INTERVALS
...................3-1
PRE-OPERATION INSPECTION
AND MAINTENANCE
................................3-4
ENGINE
......................................................3-5
CHASSIS
.................................................3-24
ELECTRICAL
...........................................3-46

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 ...........................................5-42
STEERING ...............................................5-48
SWINGARM .............................................5-53
REAR SHOCK ABSORBER ....................5-61

CHAPTER 6
ELECTRICAL
ELECTRICAL COMPONENTS
AND WIRING DIAGRAM ...........................6-1
MAP-CONTROLLED CDI UNIT .................6-2
IGNITION SYSTEM ....................................6-3
TPS (THROTTLE POSITION SENSOR)
SYSTEM .....................................................6-7
CHAPTER 7
TUNING
ENGINE ......................................................7-1
CHASSIS .................................................7-11

GEN
INFO
1 - 1
DESCRIPTION
EC100000
GENERAL INFORMATION
EC110000
DESCRIPTION
1Clutch lever
2Hot starter lever
3Front brake lever
4Throttle grip
5Radiator cap
6Fuel tank cap
7“ENGINE STOP” button
8Kick starter
9Fuel tank
0Radiator
ACoolant drain bolt
BRear brake pedal
CValve joint
DFuel cock
ECold starter knob
FDrive chain
GAir cleaner
HShift pedal
IOil dipstick
JFront forkNOTE:
The machine you have purchased may differ
slightly from those shown in the following.
Designs and specifications are subject to
change without notice.

GEN
INFO
ALLGEMEINE ANGABEN
FAHRZEUGBESCHREIBUNG
1Kupplungshebel
2Warmstarthebel
3Handbremshebel
4Gasdrehgriff
5Kühlerverschlußdeckel
6Tankverschluß
7Motorstoppschalter “ENGINE STOP”
8Kickstarterhebel
9Kraftstofftank
0Kühler
AKühlflüssigkeits-Ablaßschraube
BFußbremshebel
CVentilverbindung
DKraftstoffhahn
EChokehebel
FAntriebskette
GLuftfilter
HFußschalthebel
IÖlmeßstab
JTeleskopgabel
HINWEIS:
 Die Abbildungen in vorliegender Anleitung
können leicht vom eigentlichen Modell
abweichen und dienen daher lediglich zur
Bezugnahme.
 Änderungen an Design und technischen
Daten jederzeit vorbehalten.
DESCRIPTION
FAHRZEUGBESCHREIBUNG
RENSEIGNEMENTS
GENERAUX
DESCRIPTION
1Levier d’embrayage
2Levier de démarrage à chaud
3Levier de frein avant
4Poignée des gaz
5Bouchon de radiateur
6Bouchon de réservoir de carburant
7Bouton “ENGINE STOP”
8Kick
9Réservoir de carburant
0Radiateur
ABoulon de vidange du liquide de refroidissement
BPédale de frein arrière
CClapet de reniflard
DRobinet de carburant
ECommande de départ à froid
FChaîne de transmission
GFiltre à air
HSélecteur
IJauge d’huile
JFourche
N.B.:
 Votre moto diffère peut-être partiellement de
celle montrée sur ces photos.
 La conception et les caractéristiques peuvent être
modifiées sans préavis.
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