2006 YAMAHA YZ450F clutch

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 - 8
SPECIAL TOOLS
YM-01501, 90890-01501 Cap bolt ring wrench
This tool is used to loosen or tighten the damper
assembly.YM-01501 90890-01501
YM-A0948, 90890-01502 Fork seal driver
This tool is used when install the fork oil seal.YM-A0948 90890-01502
YU-3112-C, 90890-03112 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
YM-4118, 90890-04118
YM-4099, 90890-04099Valve guide reamer
Intake 4.5 mm (0.18 in)
Exhaust 5.0 mm (0.20 in)
This tool is needed to rebore the new valve guide.YM-4118
YM-4099 90890-04118
90890-04099
Part number Tool name/How to use Illustration

1 - 10
GEN
INFO
CONTROL FUNCTIONS
EC150000
CONTROL FUNCTIONS
EC151000
“ENGINE STOP” BUTTON
The “ENGINE STOP” button 1 is located on
the left handlebar. Continue pushing the
“ENGINE STOP” button till the engine comes
to a stop.
EC152000
CLUTCH LEVER
The clutch lever 1 is located on the left han-
dlebar; it disengages or engages the clutch.
Pull the clutch lever to the handlebar to disen-
gage the clutch, and release the lever to
engage the clutch. The lever should be pulled
rapidly and released slowly for smooth starts.
EC153000
SHIFT PEDAL
The gear ratios of the constant-mesh 5 speed
transmission are ideally spaced. The gears
can be shifted by using the shift pedal 1 on
the left side of the engine.
EC154000
KICK STARTER
Rotate the kick starter 1 away from the
engine. Push the starter down lightly with your
foot until the gears engage, then kick smoothly
and forcefully to start the engine. This model
has a primary kick starter so the engine can be
started in any gear if the clutch is disengaged.
In normal practices, however, shift to neutral
before starting.
1
EC155001
THROTTLE GRIP
The throttle grip 1 is located on the right han-
dlebar; it accelerates or decelerates the
engine. For acceleration, turn the grip toward
you; for deceleration, turn it away from you.

SPEC
2 - 2 Oil type or grade:
Engine oil (For USA and CDN)
At 5 °C (40 °F) or higher È
Yamalube 4 (20W-40) or SAE 20W-40 type SG
motor oil (Non-Friction modified)
At 15 °C (60 °F) or lower É
Yamalube 4 (10W-30) or SAE 10W-30 type SG
motor oil (Non-Friction modified) and/or
Yamalube 4-R (15W-50) (Non-Friction modi-
fied)
(Except for USA and CDN)
API “SG” or higher grade
Oil capacity:
Engine oil
Periodic oil change 0.95 L (0.84 Imp qt, 1.00 US qt)
With oil filter replacement 1.0 L (0.88 Imp qt, 1.06 US qt)
Total amount 1.2 L (1.06 Imp qt, 1.27 US qt)
Coolant capacity (including all routes): 0.99 L (0.87 Imp qt, 1.05 US qt)
Air filter: Wet type element
Fuel:
Type Premium unleaded gasoline only with a
research octane number of 95 or higher.
Tank capacity 7.0 L (1.54 Imp gal, 1.85 US gal)
Carburetor:
Type FCR MX39
Manufacturer KEIHIN
Spark plug:
Type/manufacturer CR8E/NGK (resistance type)
Gap 0.7 ~ 0.8 mm (0.028 ~ 0.031 in)
Clutch type: Wet, multiple-disc
-20
-4-10
140
3010
5020
6830
8640 50
104
122 ˚CTemp.
˚F
10W-30
10W-40
20W-40
20W-50
15W-40
GENERAL SPECIFICATIONS
2

SPEC
2 - 8 Clutch:
Friction plate thickness 2.92 ~ 3.08 mm
(0.115 ~ 0.121 in)2.8 mm
(0.110 in)
Quantity 9 ----
Clutch plate thickness 1.1 ~ 1.3 mm (0.043 ~ 0.051 in) ----
Quantity 8 ----
Warp limit ---- 0.1 mm
(0.004 in)
Clutch spring free length 47.8 mm (1.88 in) 46.8 mm
(1.84 in)
Quantity 6 ----
Clutch housing thrust clearance 0.10 ~ 0.35 mm
(0.0039 ~ 0.0138 in)----
Clutch housing radial clearance 0.010 ~ 0.044 mm
(0.0004 ~ 0.0017 in)----
Clutch release method Inner push, cam push ----
Shifter:
Shifter type Cam drum and guide bar ----
Guide bar bending limit ---- 0.05 mm
(0.002 in)
Kick starter:
Type Ratchet type ----
Carburetor:
I.D. mark 2S21 00 ----
Main jet (M.J) #165 ----
Main air jet (M.A.J)ø2.0 ----
Jet needle - clip position (J.N) NFPR-4 ----
Cutaway (C.A) 1.5 ----
Pilot jet (P.J) #42 ----
Pilot air jet (P.A.J) #100 ----
Pilot outlet (P.O)ø0.9 ----
Pilot screw (example) (P.S) 2-1/8 ----
Bypass (B.P)ø1.0 ----
Valve seat size (V.S)ø3.8 ----
Starter jet (G.S) #72 ----
Leak jet (Acc. P) #55 ----
Float height (F.H) 8 mm (0.31 in) ----
Engine idle speed 1,900 ~ 2,100 r/min ----
Intake vacuum 28.0 ~ 33.3 kPa
(210 ~ 250 mmHg,
8.27 ~ 9.84 inHg)----
Hot starter lever free play 3 ~ 6 mm (0.12 ~ 0.24 in) ----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 - 12
NOTE:
- marked portion shall be checked for torque tightening after break-in or before each race.
NOTE:
*1: Tighten the cylinder head bolts to 30 Nm (3.0 m  kg, 22 ft  lb) in the proper tightening sequence,
remove and retighten the cylinder head bolts to 20 Nm (2.0 m  kg, 14 ft  lb) in the proper tightening
sequence, and then tighten the cylinder head bolts further to reach the specified angle 180° in the
proper tightening sequence.Crankcase cover (right) M6 × 1.0 8 10 1.0 7.2
M6 × 1.0 2 12 1.2 8.7
Crankcase cover (left) M6 × 1.0 8 10 1.0 7.2
Crankcase M6 × 1.0 12 12 1.2 8.7
Clutch cable holder M6 × 1.0 2 10 1.0 7.2
Oil drain bolt (crankcase right) M10 × 1.25 1 20 2.0 14
(crankcase left) M8 × 1.25 1 20 2.0 14
Oil check bolt (crankcase) M6 × 1.0 1 10 1.0 7.2
Oil strainer M6 × 1.0 1 10 1.0 7.2
Crankcase bearing stopper M6 × 1.0 4 14 1.4 10
Crankcase bearing stopper M6 × 1.0 8 10 1.0 7.2
Drive axle oil seal stopper M6 × 1.0 2 10 1.0 7.2
Ratchet wheel guide M6 × 1.0 2 12 1.2 8.7
Kick starter M8 × 1.25 1 33 3.3 24
Screw (kick starter) M6 × 1.0 1 7 0.7 5.1
Primary drive gear M20 × 1.0 1 110 11.0 80
Clutch boss M20 × 1.0 1 75 7.5 54
Clutch cable adjust bolt and locknut M6 × 0.75 1 4 0.4 2.9
Clutch spring M6 × 1.0 6 10 1.0 7.2
Balancer M10 × 1.0 1 45 4.5 32
Balancer driven gear M14 × 1.0 1 50 5.0 36
Balancer weight plate M6 × 1.0 3 10 1.0 7.2
Drive sprocket M20 × 1.0 1 75 7.5 54
Drive sprocket cover M6 × 1.0 2 8 0.8 5.8
Shift pedal M6 × 1.0 1 12 1.2 8.7
Shift guide M6 × 1.0 2 10 1.0 7.2
Stopper lever M6 × 1.0 1 10 1.0 7.2
Segment M8 × 1.25 1 30 3.0 22 Part to be tightened Thread size Q’tyTightening torque
Nm m·kg ft·lb
MAINTENANCE SPECIFICATIONS