2005 YAMAHA YZ450F torque

SPEC
2 - 18
EC220001
GENERAL TORQUE SPECIFICATIONS
This chart specifies torque for standard fasten-
ers with standard I.S.O. pitch threads. Torque
specifications for special components or
assemblies are included in the applicable sec-
tions of this book. To avoid warpage, tighten
multi-fastener assemblies in a crisscross fash-
ion, in progressive stages, until full torque is
reached. Unless otherwise specified, torque
specifications call for clean, dry threads. Com-
ponents should be at room temperature.
A: Distance between flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
A
(Nut)B
(Bolt)TORQUE
SPECIFICATION
Nm mkg ftlb
10 mm
12 mm
14 mm
17 mm
19 mm
22 mm6 mm
8 mm
10 mm
12 mm
14 mm
16 mm6
15
30
55
85
1300.6
1.5
3.0
5.5
8.5
134.3
11
22
40
61
94
Unit Read Definition Measure
mm
cmmillimeter
centimeter10
-3 meter
10-2 meterLength
Length
kg kilogram 10
3 gram Weight
N Newton 1 kg
× m/sec
2 Force
Nm
m  kgNewton meter
Meter kilogramN
× m
m
× kgTorque
Torque
Pa Pascal N/m
2Pressure
N/mm Newton per millimeter N/mm Spring rate
L
cm
3 Liter
Cubic centimeter—
—Volume or capacity
Volume or capacity
r/min Revolution per minute—Engine speed
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS

3 - 43
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
Tighten the ring nut 3 using ring nut
wrench 4.
NOTE:
Apply the lithium soap base grease on the
thread of the steering shaft.
Set the torque wrench to the ring nut
wrench so that they form a right angle.
Ring nut wrench:
YU-33975/90890-01403
T R..
Ring nut (initial tightening):
38 Nm (3.8 m  kg, 27 ft  lb)
Loosen the ring nut one turn.
Retighten the ring nut using the ring nut
wrench.
WARNING
Avoid over-tightening.
T R..
Ring nut (final tightening):
7 Nm (0.7 m  kg, 5.1 ft  lb)
Check the steering shaft by turning it lock
to lock. If there is any binding, remove the
steering shaft assembly and inspect the
steering bearings.
Install the plain washer 5, handle crown
6, plain washer 7, steering shaft nut 8,
steering shaft cap 9, handlebar 0, han-
dlebar holder A and number plate B.
NOTE:
The upper handlebar holder should be
installed with the punched mark a for-
ward.
Install the handlebar so that the marks b
are in place on both sides.
Insert the end of fuel breather hose C into
the hole in the steering shaft cap.
CAUTION:
First tighten the bolts on the front side of
the handlebar holder, and then tighten
the bolts on the rear side.

4 - 28
ENG
With the rod fully wound and the chain ten-
sioner UP mark a facing upward, install
the gasket 1 and the chain tensioner 2,
and tighten the bolt 3 to the specified
torque.
T R..
Bolt (timing chain tensioner):
10 Nm (1.0 m  kg, 7.2 ft  lb)
Release the screwdriver, check the ten-
sioner rod to come out and tighten the
gasket 4 and the cap bolt 5 to the speci-
fied torque.
T R..
Tensioner cap bolt:
7 Nm (0.7 m  kg, 5.1 ft  lb)
5
4New
3. Turn:
Crankshaft
Counterclockwise several turns
4. Check:
Rotor “I” mark
Align with the crankcase stationary
pointer.
Camshaft match marks
Align with the cylinder head surface.
Out of alignment → Adjust.
CAMSHAFTS

4 - 31
ENGCYLINDER HEAD
ASSEMBLY AND INSTALLATION
1. Install:
Timing chain guide (front) 1
Dowel pin 2
Cylinder head gasket 3
Cylinder head 4
NOTE:
While pulling up the timing chain, install the
timing chain guide (front) and cylinder head.
New
2. Install:
Plain washer 1
Bolt [L = 160 mm (6.30 in)] 2
Bolt [L = 150 mm (5.91 in)] 3
Installation steps:
CAUTION:
Tighten the cylinder head using the rota-
tion angle procedure to obtain uniform
tightening torque.
Wash the threads and contact surfaces of
the bolts, the contact surfaces of the plain
washers, the contact surface of the cylin-
der head, and the threads of the crank-
case.
Apply the molybdenum disulfide grease on
the threads and contact surfaces of the
bolts and on both contact surfaces of the
plain washers.
Install the plain washers and bolts.
Tighten the bolts to the specified torque in
two or three steps in the proper tightening
sequence as shown.
T R..
Bolts (cylinder head):
1st:
30 Nm (3.0 m  kg, 22 ft  lb)

4 - 32
ENG
Remove the bolts.
Again apply the molybdenum disulfide
grease on the threads and contact sur-
faces of the bolts and on both contact sur-
faces of the plain washers.
Retighten the bolts.
NOTE:
Tighten the bolts to the specified torque in
two or three steps in the proper tightening
sequence as shown.
T R..
Bolts (cylinder head):
2nd:
20 Nm (2.0 m  kg, 14 ft  lb)
Put a mark on the corner 1 of the bolt
(cylinder head) and the cylinder head 2
as shown.
NOTE:
Tighten the bolts 90° in each of the two
steps to reach the specified angle of 180° in
the proper tightening sequence as shown.
T R..
Bolts (cylinder head):
Final:
Specified angle 180°
1
2
180˚
3. Install:
Cable guide 1
Nut (cylinder head) 2
T R..10 Nm (1.0 m · kg, 7.2 ft · lb)
4. Install:
Copper washer 1
Oil delivery pipe 2
Union bolt (M8) 3
Union bolt (M10) 4
New
T R..18 Nm (1.8 m · kg, 13 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
CYLINDER HEAD

5 - 34
CHASFRONT FORK
9. Tighten:
Base valve 1
NOTE:
Hold the damper assembly with the cap bolt
ring wrench 2 and use the cap bolt wrench 3
to tighten the base valve with specified torque.
Cap bolt wrench:
YM-01500/90890-01500
Cap bolt ring wrench:
YM-01501/90890-01501
T R..29 Nm (2.9 m · kg, 21 ft · lb)
10. After filling, pump the damper assembly 1
slowly up and down more than 10 times to
distribute the fork oil.
11. While protecting the damper assembly 1
with a rag and compressing fully, allow
excessive oil to overflow on the base valve
side.
CAUTION:
Take care not to damage the damper
assembly.
12. Allow the overflowing oil to escape at the
hole a in the damper assembly.

5 - 38
CHASFRONT FORK
26. Install:
Push rod 1
Copper washer 2
Adjuster 3
To damper assembly 4.
NOTE:
While compressing the inner tube 5, set the
cap bolt ring wrench 7 between the inner
tube and locknut 6.
Fully finger tighten the adjuster onto the
damper assembly.
Cap bolt ring wrench:
YM-01501/90890-01501
New
27. Inspect:
Gap a between adjuster 1 and locknut
2.
Out of specification → Retighten and
readjust the locknut.
NOTE:
If the adjuster is installed out of specification,
proper damping force cannot be obtained.
Gap
a between adjuster and
locknut:
0.5 ~ 1.0 mm (0.02 ~ 0.04 in)
28. Tighten:
Adjuster (locknut) 1
NOTE:
Hold the locknut 2 and tighten the adjuster
with specified torque.
T R..29 Nm (2.9 m · kg, 21 ft · lb)

5 - 40
CHAS
32. Install:
Protector guide 1
Installation
1. Install:
Front fork 1
NOTE:
Temporarily tighten the pinch bolts (under
bracket).
Do not tighten the pinch bolts (handle crown)
yet.
2. Tighten:
Damper assembly 1
NOTE:
Use the cap bolt ring wrench 2 to tighten the
damper assembly with specified torque.
Cap bolt ring wrench:
YM-01501/90890-01501
T R..30 Nm (3.0 m · kg, 22 ft · lb)
3. Adjust:
Front fork top end a
Front fork top end (standard) a:
Zero mm (Zero in)
FRONT FORK