2006 YAMAHA YZ250F torque

SPEC
2 - 17
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 - 42
INSP
ADJ
STEERING HEAD INSPECTION AND ADJUSTMENT
Tighten the steering ring nut 3 using
steering nut wrench 4.
NOTE:
Apply the lithium soap base grease on the
thread of the steering stem.
Set the torque wrench to the steering nut
wrench so that they form a right angle.
Steering nut wrench:
YU-33975/90890-01403
T R..
Steering ring nut (initial tightening):
38 Nm (3.8 m  kg, 27 ft  lb)
Loosen the steering ring nut one turn.
Retighten the steering ring nut using the
steering nut wrench.
WARNING
Avoid over-tightening.
T R..
Steering ring nut (final tightening):
7 Nm (0.7 m  kg, 5.1 ft  lb)
Check the steering stem by turning it lock
to lock. If there is any binding, remove the
steering stem assembly and inspect the
steering bearings.
Install the washer 5, upper bracket 6,
washer 7, steering stem nut 8, handle-
bar 9, handlebar upper holder 0 and
number plate A.
NOTE:
The handlebar upper holder should be
installed with the punched mark a forward.
Install the handlebar so that the marks b
are in place on both sides.
Install the handlebar so that the projection
c of the handlebar upper holder is posi-
tioned at the mark on the handlebar as
shown.
Insert the end of fuel breather hose B into
the hole in the steering stem.
CAUTION:
First tighten the bolts on the front side of
the handlebar upper holder, and then
tighten the bolts on the rear side.

4 - 29
ENG
With the rod fully wound and the chain ten-
sioner UP mark a facing upward, install
the gasket 1 and the timing chain ten-
sioner 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
4
3. Turn:
Crankshaft
Counterclockwise several turns.
4. Check:
Rotor T.D.C. mark
Align with the crankcase align mark.
Camshaft match marks
Align with the cylinder head surface.
Out of alignment → Adjust.
5. Install:
Timing mark accessing screw 1
Crankshaft end accessing screw 2
CAMSHAFTS

5 - 35
CHAS
9. Check that the damper assembly is fully
stretched. Not fully stretched → Repeat the
steps 2 to 8.
10. 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)
11. After filling, pump the damper assembly 1
slowly up and down more than 10 times to
distribute the fork oil.
12. 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.
13. Allow the overflowing oil to escape at the
hole a in the damper assembly.
FRONT FORK

5 - 39
CHASFRONT FORK
27. 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
28. Inspect:
Gap a between the adjuster 1 and lock-
nut 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 the adjuster and
locknut:
0.5 ~ 1.0 mm (0.02 ~ 0.04 in)
29. 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 - 41
CHAS
33. Install:
Protector guide 1
NOTE:
Install the protector guide with its wider side a
facing downward.
Installation
1. Install:
Front fork 1
NOTE:
Temporarily tighten the pinch bolts (lower
bracket).
Do not tighten the pinch bolts (upper bracket)
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:
5 mm (0.20 in)
FRONT FORK

5 - 42
CHAS
4. Tighten:
Pinch bolt (upper bracket) 1
Pinch bolt (lower bracket) 2
CAUTION:
Tighten the lower bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
5. Install:
Protector 1
Bolt (protector) 2
T R..7 Nm (0.7 m · kg, 5.1 ft · lb)
6. Adjust:
Rebound damping force
NOTE:
Turn in the damping adjuster 1 finger-tight
and then turn out to the originally set position.
7. Adjust:
Compression damping force
NOTE:
Turn in the damping adjuster 1 finger-tight
and then turn out to the originally set position.
FRONT FORK

5 - 53
CHAS
9. After tightening the nut, check the steering
for smooth movement. If not, adjust the
steering by loosening the steering ring nut
little by little.
10. Adjust:
•Front fork top end a
Front fork top end (standard) a:
5 mm (0.20 in)
11. Tighten:
•Pinch bolt (upper bracket) 1
•Pinch bolt (lower bracket) 2
CAUTION:
Tighten the lower bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
T R..23 Nm (2.3 m · kg, 17 ft · lb)
T R..20 Nm (2.0 m · kg, 14 ft · lb)
STEERING