2006 YAMAHA YZ450F steering

CHAPTER 4
ENGINE
SEAT, FUEL TANK AND SIDE
COVERS ....................................................4-1
EXHAUST PIPE AND SILENCER .............4-3
RADIATOR ................................................4-6
CARBURETOR ..........................................4-9
CAMSHAFTS ...........................................4-22
CYLINDER HEAD ....................................4-30
VALVES AND VALVE SPRINGS ............4-34
CYLINDER AND PISTON ........................4-43
CLUTCH ...................................................4-49
OIL FILTER, WATER PUMP AND
CRANKCASE COVER (RIGHT) ..............4-56
BALANCER .............................................4-63
OIL PUMP ................................................4-66
KICK AXLE AND SHIFT SHAFT .............4-70
CDI MAGNETO ........................................4-78
ENGINE REMOVAL .................................4-81
CRANKCASE AND CRANKSHAFT ........4-86
TRANSMISSION, SHIFT CAM AND
SHIFT FORK ............................................4-95
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL .......5-1
FRONT BRAKE AND REAR BRAKE .....5-10
FRONT FORK ..........................................5-26
HANDLEBAR ...........................................5-43
STEERING ...............................................5-49
SWINGARM .............................................5-54
REAR SHOCK ABSORBER ....................5-62

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 positive
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 - 7
SPECIAL TOOLS
EC140001
SPECIAL TOOLS
The proper special tools are necessary for complete and accurate tune-up and assembly. Using the
correct special tool will help prevent damage caused by the use of improper tools or improvised
techniques. The shape and part number used for the special tool differ by country, so two types are
provided. Refer to the list provided to avoid errors when placing an order.
NOTE:
For U.S.A. and Canada, use part number starting with “YM-”, “YU-” or “ACC-”.
For others, use part number starting with “90890-”.
Part number Tool name/How to use Illustration
YU-3097, 90890-01252
YU-1256Dial gauge and stand
Stand
These tools are used to check each part for runout or
bend.YU-3097
YU-125690890-01252
YU-90050, 90890-01274
YU-90050, 90890-01275
YU-91044, 90890-04081
YU-90063, 90890-01278Crankshaft installing tool
Crankshaft installing pot
Crankshaft installing bolt
Spacer (crankshaft installer)
Adapter (M12)
These tools are used to install the crankshaft.YU-90050
YU-90063
YU-9104490890-01274
90890-01275
90890-01278
90890-04081
YU-1304, 90890-01304 Piston pin puller
This tool is used to remove the piston pin.YU-1304 90890-01304
YU-24460-01, 90890-01325
YU-33984, 90890-01352Radiator cap tester
Adapter
These tools are used for checking the cooling sys-
tem.YU-24460-01
YU-3398490890-01325
90890-01352
YM-04151, 90890-04151 Rotor puller
This tool is used to remove the flywheel magneto.YM-04151 90890-04151
YU-33975, 90890-01403 Ring nut wrench
This tool is used when tighten the steering ring nut to
specification.YU-33975 90890-01403
YM-01500, 90890-01500 Cap bolt wrench
This tool is used to loosen or tighten the base valve.YM-01500 90890-01500

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
Tightening of brake hose holder
Brake pedal to frame
Brake disc to wheel
Tightening of union bolt
Master cylinder to frame
Tightening of air bleeder
Tightening of brake hose holder
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
swingarm
Wheel Installation of wheel Front
Rear
Brake Front
Rear
Fuel system
Lubrication system

SPEC
2 - 13
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 454 mm (17.9 in)← 449 mm (17.7 in)
Spring rate, STD K = 4.6 N/mm
(0.469 kg/mm,
26.3 lb/in)K = 4.5 N/mm
(0.459 kg/mm,
25.7 lb/in)----
Optional spring Yes← ----
Oil capacity 542 cm
3
(19.1 Imp oz,
18.3 US oz) 532 cm3
(18.7 Imp oz,
18.0 US oz) ----
Oil grade Suspension oil
“S1”← ----
Inner tube outer diameter 48 mm (1.89 in)← ----
Front fork top end Zero mm (Zero in)← ----
Rear suspension: USA, CDN,
AUS, NZ, ZAEUROPE
Shock absorber travel 131.5 mm (5.18 in)← ----
Spring free length Approx. 275 mm
(10.83 in)← ----
Fitting length One I.D. mark
264 mm (10.39 in)One I.D. mark
262 mm (10.31 in) ----
Two I.D. marks
270 mm (10.63 in)Two I.D. marks
268 mm (10.55 in) ----
Three I.D. marks
261.5 mm
(10.30 in)Three I.D. marks
259.5 mm
(10.22 in)----
One I.D. mark
255.5 ~ 273.5 mm
(10.06 ~ 10.77 in)←----
Two I.D. marks
261.5 ~ 279.5 mm
(10.30 ~ 11.00 in)←----
Three I.D. marks
253.0 ~ 271.0 mm
(9.96 ~ 10.67 in)←----
Spring rate, STD K = 54.0 N/mm
(5.50 kg/mm,
308.0 lb/in)←----
Optional spring Yes← ----
Enclosed gas pressure 1,000 kPa
(10 kg/cm
2,
142 psi)← ----
MAINTENANCE SPECIFICATIONS

SPEC
2 - 15
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
Handlebar holder (lower) M12 × 1.25 2 40 4.0 29
Steering ring nut M28 × 1.0 1 Refer to NOTE.
Front fork and damper assembly M51 × 1.5 2 30 3.0 22
Front fork and adjuster M22 × 1.25 2 55 5.5 40
Damper assembly and base valve M42 × 1.5 2 29 2.9 21
Adjuster and damper assembly M12 × 1.25 2 29 2.9 21
Bleed screw (front fork) and base valve M5 × 0.8 2 1 0.1 0.7
Front fork and protector M6 × 1.0 6 7 0.7 5.1
Protector and brake hose holder M6 × 1.0 2 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 (nut) 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 bracket M6 × 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
Front brake caliper and brake hose holder M6 × 1.0 1 10 1.0 7.2
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
Footrest bracket and frame M10 × 1.25 4 55 5.5 40
Brake pedal mounting M8 × 1.25 1 26 2.6 19
Rear brake master cylinder and frame M6 × 1.0 2 10 1.0 7.2
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
MAINTENANCE SPECIFICATIONS

2 - 21
SPECCABLE ROUTING DIAGRAM
EC240000
CABLE ROUTING DIAGRAM
1Fuel tank breather hose
2Radiator hose 1
3Cylinder head breather hose
4Hose holder
5Radiator hose 4
6Clutch cable
7Connector cover
8Fuel hose
9TPS (throttle position sensor)
lead
0Hot starter cable
ACarburetor breather hose
BCarburetor overflow hoseÈInsert the end of the fuel tank
breather hose into the hole in
the steering shaft.
ÉPass the cylinder head breather
hose on the outside of the radia-
tor hose 1 and between the radi-
ator hose 4 and frame.
ÊAlign the paint on the cylinder
head breather hose with the
front edge of the hose holder.
ËPass the clutch cable through
the cable guide.ÌPass the clutch cable in front of
the radiator mounting boss.
ÍInstall the connector cover so
that it does not come in between
the radiator hose 1 and radiator.
ÎPass the fuel hose between the
hot starter cable and TPS lead.
ÏPass the carburetor breather
hoses and overflow hose so that
all there hoses do not contact
the rear shock absorber.
B
AA
B
Ï
B
A
0
9
3
2
ÌÉ
1
È
Í
6
5
4 Ë
A
Ê8
Î
7

3 - 3
INSP
ADJ
MAINTENANCE INTERVALS
FRONT FORK OIL SEAL AND DUST
SEAL
Clean and lube Lithium base grease
PROTECTOR GUIDE
Replace
REAR SHOCK ABSORBER
(After
rain ride)
Inspect and adjust
LubeMolybdenum disulfide
grease
Replace spring seat Every one year
Retighten
CHAIN GUARD AND ROLLERS
Inspect
SWINGARM
Molybdenum disulfide
grease
Inspect, lube and retighten
RELAY ARM, CONNECTING ROD
Molybdenum disulfide
grease
Inspect, lube and retighten
STEERING HEAD
Inspect free play and retighten
Clean and lube Lithium base grease
Replace bearing
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
Yamaha cable lube or
SAE 10W-30 motor oil Check routing and connection
Lubricate
HOT STARTER, CLUTCH LEVER
Inspect free playItemAfter
break-inEvery
race
Every
third
(or
500 km)Every
fifth
(or
1,000 km)As re-
quiredRemarks