2006 YAMAHA YZ450F radiator

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

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
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

SPEC
2 - 9 Lubrication system:
Oil filter type Paper type ----
Oil pump type Trochoid type ----
Tip clearance “A”0.12 mm or less
(0.0047 in or less)0.20 mm
(0.008 in)
Tip clearance “B”0.09 ~ 0.17 mm
(0.0035 ~ 0.0067 in)0.24 mm
(0.009 in)
Side clearance 0.03 ~ 0.10 mm
(0.0012 ~ 0.0039 in)0.17 mm
(0.007 in)
Bypass valve setting pressure 40 ~ 80 kPa (0.4 ~ 0.8 kg/cm
2,
5.69 ~ 11.38 psi)----
Cooling:
Radiator core size
Width 120.2 mm (4.73 in) ----
Height 240 mm (9.45 in) ----
Thickness 22 mm (0.87 in) ----
Radiator cap opening pressure 110 kPa (1.1 kg/cm
2, 15.6 psi) ----
Radiator capacity (total) 0.56 L (0.49 Imp qt, 0.59 US qt) ----
Water pump
Type Single-suction centrifugal pump ----Item Standard Limit
MAINTENANCE SPECIFICATIONS

SPEC
2 - 11 Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Spark plug M10S × 1.0 1 13 1.3 9.4
Camshaft cap M6 × 1.0 10 10 1.0 7.2
Cylinder head blind plug screw M12 × 1.0 1 28 2.8 20
Cylinder head (stud bolt) M8 × 1.25 1 15 1.5 11
(bolt) M10 × 1.25 4 Refer to NOTE.*
1
(bolt) M6 × 1.0 2 10 1.0 7.2
Cylinder head cover M6 × 1.0 2 10 1.0 7.2
Cylinder M6 × 1.0 1 10 1.0 7.2
Timing chain tensioner M6 × 1.0 2 10 1.0 7.2
Tensioner cap bolt M6 × 1.0 1 7 0.7 5.1
Timing chain guide (rear) M6 × 1.0 2 10 1.0 7.2
Exhaust pipe (nut) M8 × 1.25 1 13 1.3 9.4
(bolt) M8 × 1.25 1 24 2.4 17
Silencer M8 × 1.25 2 35 3.5 25
Silencer clamp M8 × 1.25 1 16 1.6 11
Exhaust pipe protector M6 × 1.0 3 10 1.0 7.2
Carburetor joint M6 × 1.0 3 10 1.0 7.2
Carburetor joint clamp M4 × 0.7 1 3 0.3 2.2
Air filter case M6 × 1.0 2 8 0.8 5.8
Air filter joint clamp M6 × 1.0 1 3 0.3 2.2
Air filter joint and air filter case M5 × 0.8 1 4 0.4 2.9
Throttle cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Throttle cable (pull) M6 × 1.0 1 4 0.4 2.9
Throttle cable (return) M12 × 1.0 1 11 1.1 8.0
Throttle cable cover M5 × 0.8 2 4 0.4 2.9
Hot starter plunger M12 × 1.0 1 2 0.2 1.4
Hot starter cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Air filter element M6 × 1.0 1 2 0.2 1.4
Radiator panel (upper) M6 × 1.0 2 10 1.0 7.2
Radiator M6 × 1.0 4 10 1.0 7.2
Radiator hose clamp M6 × 1.0 8 2 0.2 1.4
Radiator pipe 1, 2 M6 × 1.0 2 10 1.0 7.2
Impeller M8 × 1.25 1 14 1.4 10
Water pump housing cover M6 × 1.0 3 10 1.0 7.2
Coolant drain bolt M6 × 1.0 1 10 1.0 7.2
Oil pump cover M4 × 0.7 1 2 0.2 1.4
Oil pump M6 × 1.0 2 10 1.0 7.2
Engine oil drain bolt (oil filter) M6 × 1.0 1 10 1.0 7.2
Oil filter cover M6 × 1.0 2 10 1.0 7.2
Oil check bolt (cylinder head) M6 × 1.0 1 10 1.0 7.2
Oil hose clamp—220.21.4
Clutch cover M6 × 1.0 7 10 1.0 7.2
MAINTENANCE SPECIFICATIONS

SPEC
2 - 16
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
Rear wheel axle and nut M20 × 1.5 1 125 12.5 90
Driven sprocket and wheel hub M8 × 1.25 6 42 4.2 30
Nipple (spoke)—72 3 0.3 2.2
Disc cover and rear brake caliper M6 × 1.0 2 10 1.0 7.2
Protector and rear brake caliper M6 × 1.0 2 7 0.7 5.1
Chain puller adjust bolt and locknut M8 × 1.25 2 16 1.6 11
Engine mounting:
Engine upper bracket and frame M10 × 1.25 4 55 5.5 40
Engine lower bracket and frame M8 × 1.25 4 34 3.4 24
Engine and engine bracket (front) M10 × 1.25 1 53 5.3 38
Engine and engine bracket (upper) M10 × 1.25 1 55 5.5 40
Engine and frame (lower) M10 × 1.25 1 53 5.3 38
Engine guard M6 × 1.0 1 10 1.0 7.2
Engine skid plate mounting M6 × 1.0 3 10 1.0 7.2
CDI unit bracket mounting M6 × 1.0 2 7 0.7 5.1
Cable guide and CDI unit bracket M5 × 0.8 2 4 0.4 2.9
Cable guide and frame M5 × 0.8 1 5 0.5 3.6
Pivot shaft and nut M16 × 1.5 1 85 8.5 61
Relay arm and swingarm M14 × 1.5 1 70 7.0 50
Relay arm and connecting rod M14 × 1.5 1 80 8.0 58
Connecting rod and frame M14 × 1.5 1 80 8.0 58
Rear shock absorber and frame M10 × 1.25 1 56 5.6 40
Rear shock absorber and relay arm M10 × 1.25 1 53 5.3 38
Rear frame and frame (upper) M8 × 1.25 1 32 3.2 23
Rear frame and frame (lower) M8 × 1.25 2 32 3.2 23
Swingarm and brake hose holder M5 × 0.8 4 2 0.2 1.4
Swingarm and patch M4 × 0.7 4 2 0.2 1.4
Drive chain tensioner mounting (upper) M8 × 1.25 1 16 1.6 11
Drive chain tensioner mounting (lower) M8 × 1.25 1 16 1.6 11
Chain support and swingarm M6 × 1.0 3 7 0.7 5.1
Seal guard and swingarm M5 × 0.8 4 6 0.6 4.3
Fuel tank mounting boss and frame M10 × 1.25 1 20 2.0 14
Fuel tank mounting M6 × 1.0 2 10 1.0 7.2
Fuel tank and fuel cock M6 × 1.0 2 6 0.6 4.3
Fuel tank and seat set bracket M6 × 1.0 1 7 0.7 5.1
Fuel tank and fuel tank bracket M6 × 1.0 4 7 0.7 5.1
Seat mounting M8 × 1.25 2 23 2.3 17
Side cover mounting M6 × 1.0 2 7 0.7 5.1
Air scoop and fuel tank M6 × 1.0 6 7 0.7 5.1
Air scoop and radiator panel (lower) M6 × 1.0 2 7 0.7 5.1
Front fender mounting M6 × 1.0 4 7 0.7 5.1
Rear fender mounting (front) M6 × 1.0 2 7 0.7 5.1
Rear fender mounting (rear) M6 × 1.0 2 16 1.6 11
Number plate M6 × 1.0 1 7 0.7 5.1
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

2 - 22
SPECCABLE ROUTING DIAGRAM
1Hot starter cable
2Clamp
3TPS (throttle position sensor)
lead
4Hump (frame)
5Neutral switch lead
6Engine bracket
7Engine skid plate stay
8CDI magneto lead
9Clutch cable
0Radiator breather hose
ARadiator hose 2
B“ENGINE STOP” button leadCSub wire harness
DGround lead
ECDI unit bracket
FCDI unit
GCable guide
HIgnition coil lead
IThrottle cable
ÈFasten the hot starter cable and
throttle cables onto the frame.
Locate the clamp ends under
the hot starter cable.ÉFasten the hot starter cable,
throttle cables, TPS lead and
ignition coil lead to the frame.
ÊFasten the TPS lead to the
frame behind its hump.
ËPass the TPS lead over the hot
starter cable.
ÌPass the neutral switch lead on
the inside of the engine bracket.
ÍPass the neutral switch lead
over the engine skid plate stay.
C-C
G-G
E
2
Õ
4 58E
É
D GGA
AB
D
5
ÌÍ Í
Í Î
F
E
D
2
2
2
Ï Ð Ò
Ñ Ó
1
G
2
3
4 2
0
8
5
9
8Ë Ê
0
0 8 5
CC
B
È 2
9
FF
Ô
Ô
B-B
A-A
I
H
3
1
C
B
A
0
0
8
5
D-D
3 F-F
6
7
2 5 0