fuel tank removal YAMAHA YZ450F 2008 Owners Manual

CONTENTS
CHAPTER 1
GENERAL INFOR-
MATION
DESCRIPTION ................. 1-1
MACHINE
IDENTIFICATION ............ 1-2
INCLUDED PARTS .......... 1-2
IMPORTANT
INFORMATION................. 1-2
CHECKING OF CONNEC-
TION ................................. 1-3
SPECIAL TOOLS ............. 1-4
CONTROL FUNCTIONS .. 1-8
STARTING AND
BREAK-IN ........................ 1-8
TORQUE-CHECK
POINTS........................... 1-11
CLEANING AND
STORAGE ...................... 1-12
CHAPTER 2
SPECIFICATIONS
GENERAL SPECIFICA-
TIONS ............................... 2-1
MAINTENANCE SPECIFICA-
TIONS ............................... 2-3
TIGHTENING
TORQUES ...................... 2-10
LUBRICATION
DIAGRAMS .................... 2-16
CABLE ROUTING
DIAGRAM ....................... 2-18
CHAPTER 3
REGULAR INSPEC-
TION AND AD-
JUSTMENTS
MAINTENANCE
INTERVALS...................... 3-1PRE-OPERATION
INSPECTION AND MAINTE-
NANCE ............................. 3-4
ENGINE ............................ 3-5
CHASSIS ........................ 3-13
ELECTRICAL ................. 3-22
CHAPTER 4
ENGINE
SEAT, FUEL TANK AND
SIDE COVERS.................. 4-1
EXHAUST PIPE AND
SILENCER ........................ 4-3
RADIATOR ....................... 4-5
CARBURETOR................. 4-7
CAMSHAFTS.................. 4-14
CYLINDER HEAD........... 4-19
VALVES AND VALVE
SPRINGS ........................ 4-22
CYLINDER AND
PISTON ........................... 4-26
CLUTCH ......................... 4-29
OIL FILTER ELEMENT
AND WATER PUMP ....... 4-33
BALANCER .................... 4-37
OIL PUMP ....................... 4-39
KICK SHAFT AND SHIFT
SHAFT ............................ 4-42
CDI MAGNETO............... 4-47
ENGINE REMOVAL ....... 4-49
CRANKCASE AND CRANK-
SHAFT ............................ 4-53
TRANSMISSION, SHIFT
CAM AND SHIFT FORK. 4-59
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR
WHEEL ............................. 5-1
FRONT BRAKE AND REAR
BRAKE ............................. 5-6
FRONT FORK................. 5-16
HANDLEBAR ................. 5-24STEERING ......................5-28
SWINGARM ....................5-32
REAR SHOCK
ABSORBER ....................5-37
CHAPTER 6
ELECTRICAL
ELECTRICAL COMPO-
NENTS AND WIRING DIA-
GRAM ...............................6-1
IGNITION SYSTEM...........6-2
THROTTLE POSITION SEN-
SOR SYSTEM ...................6-5
CHAPTER 7
TUNING
ENGINE.............................7-1
CHASSIS ..........................7-6

1-2
MACHINE IDENTIFICATION
MACHINE IDENTIFICATION
There are two significant reasons for
knowing the serial number of your
machine:
1. When ordering parts, you can
give the number to your Yamaha
dealer for positive identification of
the model you own.
2. If your machine is stolen, the au-
thorities will need the number to
search for and identify your ma-
chine.
VEHICLE IDENTIFICATION
NUMBER
The vehicle identification number "1"
is stamped on the right of the steering
head pipe.
ENGINE SERIAL NUMBER
The engine serial number "1" is
stamped into the elevated part of the
right-side of the engine.
MODEL LABEL
The model label "1" is affixed to the
frame under the rider's seat. This in-
formation will be needed to order
spare parts.
INCLUDED PARTS
DETACHABLE SIDESTAND
This sidestand "1" is used to support
only the machine when standing or
transporting it.
• Never apply additional force to
the sidestand.
• Remove this sidestand before
starting out.
VALVE JOINT
This valve joint "1" prevents fuel from
flowing out and is installed to the fuel
tank breather hose.
In this installation, make sure the
arrow faces the fuel tank and also
downward.
SPARK PLUG WRENCH
This spark plug wrench "1" is used to
remove and install the spark plug.
NIPPLE WRENCH
This nipple wrench "1" is used to
tighten the spoke.
JET NEEDLE PULL-UP TOOL
The jet needle pull-up tool "1" is used
to pull the jet needle out of the carbu-
retor.
IMPORTANT INFORMATION
PREPARATION FOR REMOVAL
AND DISASSEMBLY
1. Remove all dirt, mud, dust, and
foreign material before removal
and disassembly.
• When washing the machine with
high pressured water, cover the
parts follows.
Silencer exhaust port
Side cover air intake port
Water pump housing hole at the
bottom
Drain hole on the cylinder head
(right side)
2. Use proper tools and cleaning
equipment. Refer to "SPECIAL
TOOLS" section.
3. When disassembling the ma-
chine, keep mated parts together.
They include gears, cylinders,
pistons, and other mated parts
that have been "mated" through
normal wear. Mated parts must
be reused as an assembly or re-
placed.
4. During the machine disassembly,
clean all parts and place them in
trays in the order of disassembly.
This will speed up assembly time

4-1
SEAT, FUEL TANK AND SIDE COVERS
ENGINE
SEAT, FUEL TANK AND SIDE COVERS
REMOVING THE SEAT, FUEL TANK AND SIDE COVERS
Order Part name Q'ty Remarks
Turn the fuel cock to "OFF".
Disconnect the fuel hose.
1Seat 1
2 Air scoop (left and right) 2
3 Bolt (fuel tank) 2
4 Fuel tank 1
5 Left side cover 1 Refer to removal section.
6 Right side cover 1 Refer to removal section.
7 Number plate 1 Refer to removal section.
4

4-2
SEAT, FUEL TANK AND SIDE COVERS
REMOVING THE SIDE COVER
1. Remove:
• Bolt (side cover)
• Left side cover "1"
• Right side cover "2"
Draw the side cover downward to re-
move it because its claws "a" are in-
serted in the air filter case.
REMOVING THE NUMBER PLATE
1. Remove:
• Bolt (number plate)
• Number plate "1"
• The projection "a" is inserted into
the band of the number plate. Pull
the band off the projection before
removal.
• Remove the hot starter cable "2"
and clutch cable "3" from the cable
guide "b" on the number plate.
• The projection "c" on the lower
bracket is inserted into the number
plate. Remove the number plate by
pulling it off the projection.
INSTALLING THE AIR SCOOP
1. Install
• Air scoop "1"
• Bolt (air scoop)
Put the portion "a" of the flap of the air
filter case on the inside of the air
scoop.
Bolt (air scoop):
7 Nm (0.7 m•kg, 5.1
ft•lb)

4-14
CAMSHAFTS
CAMSHAFTS
REMOVING THE CYLINDER HEAD COVER
Order Part name Q'ty Remarks
Seat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE
COVERS" section.
Hot starter plunger Refer to "CARBURETOR" section.
Engine upper bracket (right) Refer to "ENGINE REMOVAL" section.
Engine upper bracket (left)
1 Spark plug 1
2 Cylinder head breather hose 1
3 Bolt (cylinder head cover) 2
4 Cylinder head cover 1
5 Cylinder head cover gasket 1
6 Timing chain guide (top side) 1

4-47
CDI MAGNETO
CDI MAGNETO
REMOVING THE CDI MAGNETO
Order Part name Q'ty Remarks
Seat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE
COVERS" section.
Disconnect the CDI magneto lead.
1 Left crankcase cover 1
2 Gasket 1
3 Dowel pin 2
4 Nut (rotor) 1 Refer to removal section.
5 Rotor 1 Refer to removal section.
6 Stator 1
7 Woodruff key 1

4-49
ENGINE REMOVAL
ENGINE REMOVAL
REMOVING THE ENGINE
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the frame.Refer to "HANDLING NOTE".
Seat and fuel tank Refer to "SEAT, FUEL TANK AND SIDE
COVERS" section.
Rear shock absorber Refer to "REAR SHOCK ABSORBER" sec-
tion in the CHAPTER 5.
Carburetor Refer to "CARBURETOR" section.
Exhaust pipe and silencer Refer to "EXHAUST PIPE AND SILENCER"
section.
Clutch cable Disconnect at the engine side.
Radiator Refer to "RADIATOR" section.
Shift pedalRefer to "KICK SHAFT AND SHIFT SHAFT"
section.
Cylinder head breather hose Refer to "CAMSHAFTS" section.
Drain the engine oil.Refer to "CHANGING THE ENGINE OIL"
section in the CHAPTER 3.
Ignition coil
Disconnect the CDI magneto lead.

5-16
FRONT FORK
FRONT FORK
REMOVING THE FRONT FORK
Order Part name Q'ty Remarks
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Front wheel Refer to "FRONT WHEEL AND REAR
WHEEL" section.
Front brake caliper Refer to "FRONT BRAKE AND REAR
BRAKE" section.
Number plateRefer to "SEAT, FUEL TANK AND SIDE
COVERS" section in the CHAPTER 4.
1 Protector 1
2 Pinch bolt (upper bracket) 2 Only loosening.
3 Damper assembly 1Loosen when disassembling the front fork.
Refer to removal section.
4 Pinch bolt (lower bracket) 2 Only loosening.
5 Front fork 1
21 Nm (2.1 m kg, 15 ft lb)
21 Nm (2.1 m kg, 15 ft lb)
5 Nm (0.5 m kg, 3.6 ft lb)
5 Nm (0.5 m kg, 3.6 ft lb)
7 Nm (0.7 m kg, 5.1 ft lb)

5-28
STEERING
STEERING
REMOVING THE STEERING
Order Part name Q'ty Remarks
TIGHTENING STEPS:
• Tighten ring nut. 38 Nm (3.8 m•kg, 27 ft•lb)
• Loosen it one turn.
• Retighten it. 7 Nm (0.7 m•kg, 5.1 ft•lb)
Hold the machine by placing the suitable stand
under the engine.Refer to "HANDLING NOTE".
Number plateRefer to "SEAT, FUEL TANK AND SIDE
COVERS" section in the CHAPTER 4.
Handlebar Refer to "HANDLEBAR" section.
Front fender
1 Steering stem nut 1
2 Front fork 2 Refer to "FRONT FORK" section.
3 Upper bracket 1
4 Steering ring nut 1 Refer to removal section.
5 Lower bracket 1
6 Bearing race cover 1
7 Upper bearing 1
8 Lower bearing 1 Refer to removal section.