2004 YAMAHA YZ450F steering

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

1 - 2
GEN
INFO
MACHINE IDENTIFICATION
EC120001
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 posi-
tive identification of the model you own.
2. If your machine is stolen, the authorities
will need the number to search for and
identify your machine.
EC121001
VEHICLE IDENTIFICATION NUMBER
The vehicle identification number 1 is
stamped on the right of the steering head pipe.
EC123001
ENGINE SERIAL NUMBER
The engine serial number 1 is stamped into
the elevated part of the right-side of the
engine.
EC124000
MODEL LABEL
The model label 1 is affixed to the frame
under the rider’s seat. This information will be
needed to order spare parts.

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
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

SPEC
2 - 13
MAINTENANCE SPECIFICATIONS
EC212201
CHASSIS
Item Standard Limit
Steering system:
Steering bearing type Taper roller bearing ----
Front suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Front fork travel 300 mm (11.8 in)←----
Fork spring free length 479 mm (18.9 in)←474 mm (18.7 in)
Spring rate, STD K = 4.5 N/mm
(0.459 kg/mm,
25.7 lb/in)K = 4.4 N/mm
(0.449 kg/mm,
25.1 lb/in)----
Optional spring/spacer Yes←----
Oil capacity 662 cm
3
(23.3 Imp oz,
22.4 US oz) 668 cm3
(23.5 Imp oz,
22.6 US oz) ----
Oil level 125 mm (4.92 in) 120 mm (4.72 in) ----

(From top of outer tube with inner
tube and damper rod fully com-
pressed without spring.)105 ~ 135 mm
(4.13 ~ 5.31 in)←----
Oil grade Suspension oil
“01”←----
Inner tube outer diameter 48 mm (1.89 in)←----
Front fork top endZero mm (Zero in)←----
Rear suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Shock absorber travel 132 mm
(5.20 in)←----
Spring free length 260 mm
(10.24 in)275 mm
(10.83 in)----
Fitting length 248 mm
(9.76 in)263 mm
(10.35 in)----
240.5 ~ 258.5 mm
(9.47 ~ 10.18 in)255.5 ~ 273.5 mm
(10.06 ~ 10.77 in)----
Spring rate, STD K = 52.0 N/mm
(5.30 kg/mm,
296.8 lb/in)K = Approx.
52.0 N/mm
(5.30 kg/mm,
296.8 lb/in)----
Optional spring Yes←----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)←----
Swingarm:
Swingarm free play limit
End ---- 1.0 mm (0.04 in)

SPEC
2 - 15
MAINTENANCE SPECIFICATIONS
NOTE:
1. First, tighten the ring nut approximately 38 Nm (3.8 m • kg, 27 ft • lb) by using the ring nut
wrench, then loosen the ring nut one turn.
2. Retighten the ring nut 7 Nm (0.7 m • kg, 5.1 ft • lb). Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Handle crown and outer tube M8 × 1.25 4 23 2.3 17
Under bracket and outer tube M8 × 1.25 4 20 2.0 14
Handle crown and steering shaft M24 × 1.0 1 145 14.5 105
Handlebar holder (upper) M8 × 1.25 4 28 2.8 20
Steering ring nut M28 × 1.0 1 Refer to NOTE.
Front fork and cap bolt M51 × 1.5 2 30 3.0 22
Front fork and base valve M30 × 1.0 2 55 5.5 40
Cap bolt and damper rod (front fork) M12 × 1.25 2 29 2.9 21
Bleed screw (front fork) and cap bolt M5 × 0.8 2 1 0.1 0.7
Front fork and protector M6 × 1.0 6 10 1.0 7.2
Front fork and brake hose holder M6 × 1.0 2 10 1.0 7.2
Front fork and hose cover M8 × 1.25 1 16 1.6 11
Front fork and hose cover M6 × 1.0 1 7 0.7 5.1
Throttle cable cap M5 × 0.8 2 4 0.4 2.9
Clutch lever holder mounting M5 × 0.8 2 4 0.4 2.9
Clutch lever mounting M6 × 1.0 1 4 0.4 2.9
Hot starter lever holder mounting M5 × 0.8 2 4 0.4 2.9
Front brake master cylinder and bracket M6 × 1.0 2 9 0.9 6.5
Front brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Brake lever mounting (bolt) M6 × 1.0 1 6 0.6 4.3
Brake lever mounting (nut) M6 × 1.0 1 6 0.6 4.3
Brake lever position locknut M6 × 1.0 1 5 0.5 3.6
Cable guide (front brake hose) and under
bracketM6 × 1.0 1 4 0.4 2.9
Front brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22
Front brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
Front brake caliper and front fork M8 × 1.25 2 23 2.3 17
Brake caliper (front and rear) and pad pin plug M10 × 1.0 2 3 0.3 2.2
Brake caliper (front and rear) and pad pin M10 × 1.0 2 18 1.8 13
Brake caliper (front and rear) and bleed screw M8 × 1.25 2 6 0.6 4.3
Front wheel axle and nut M16 × 1.5 1 105 10.5 75
Front wheel axle holder M8 × 1.25 4 23 2.3 17
Front brake disc and wheel hub M6 × 1.0 6 12 1.2 8.7
Rear brake disc and wheel hub M6 × 1.0 6 14 1.4 10
Brake pedal mounting M8 × 1.25 1 26 2.6 19
Rear brake master cylinder and frame M6 × 1.0 2 11 1.1 8.0
Rear brake master cylinder cap M4 × 0.7 2 2 0.2 1.4
Rear brake hose union bolt (caliper) M10 × 1.25 1 30 3.0 22
Rear brake hose union bolt (master cylinder) M10 × 1.25 1 30 3.0 22

2 - 21
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Oil tank breather hose
3Hot starter cable
4Radiator hose 4
5Clutch cable
6Cylinder head breather hose
7Radiator hose 1
8Hose guide
9Brake hose
0“ENGINE STOP” button lead
AClamp
BSub wire harness
CTPS (throttle position sen-
sor) lead
DNeutral switch lead
EOil hoseFRadiator breather hose
GCDI magneto lead
HCarburetor breather hose
IOverflow hose
ÅInsert the end of the fuel tank
breather hose into the hole in
the steering shaft cap.
ıPass the hot starter cable
between the cylinder head
breather hose, oil tank breather
hose and ignition coil, then on
the outside of the left engine
bracket.
ÇPass the clutch cable through the
cable guide.ÎPass the cylinder head breather
hose on the outside of the radia-
tor hose 1 and on the inside of the
radiator pipe (radiator hose 4).
‰Pass the clutch cable through the
cable guides.
ÏPass the clutch cable in front of
the lower radiator mounting boss.
ÌFit the brake hose into the
guides on the protector.
ÓFasten the “ENGINE STOP”
button lead and sub wire har-
ness to the frame at the protect-
ing tube of the sub wire harness
with a plastic locking tie and cut
off the tie end.
B
0
C-C
D-D
B
A
AB
DD
CC
F
D G
F
D
◊
A
G
A
A
F
AE
A
DC A A A A B A 0
1
2
3
4 5 6 7 89
‰
̉
Ï
‰
Î
Çı ÅÊÓ
È
Ô

Ò

A ˜
ˆ
Ø ∏ Œ ÂÍ
Ë HIH
E

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