2006 YAMAHA YZ250LC torque

2-13
GENERAL TORQUE SPECIFICATIONS/
DEFINITION OF UNITS
SPEC
This chart specifies torque for standard faste-
ners with standard I.S.O. pitch threads. Torque
specifications for special components or assem-
blies are included in the applicable sections of
this book. To avoid warpage, tighten multi-faste-
ner assemblies in a crisscross fashion, in pro-
gressive stages, until full torque is reached.
Unless otherwise specified, torque specifications
call for clean, dry threads. Components should
be at room temperature.
A: Distance across flats
B: Outside thread diameter
EC230000
DEFINITION OF UNITS
EC220001
GENERAL TORQUE SPECIFICATIONS
ABTORQUE SPECIFICATION
(Nut) (Bolt)
Nm m•kg ft•lb
10 mm 6 mm 6 0.6 4.3
12 mm 8 mm 15 1.5 11
14 mm 10 mm 30 3.0 22
17 mm 12 mm 55 5.5 40
19 mm 14 mm 85 8.5 61
22 mm 16 mm 130 13 94
Unit Read Definition Measure
mm milimeter 10-
3meter Length
cm centimeter 10-2meter Length
kg kilogram 103gram Weight
N Newton 1 kg ×m/sec2Force
Nm Newton meter N ×m Torque
m•kg Meter kilogrma m ×kg Torque
Pa Pascal N/m2Pressure
N/mm Newton per millimeter N/mm Spring rate
L Liter — Volume or capacity
cm3Cubic centimeter — Volume or capacity
r/min Revolution per minute — Engine speed
1P8-9-31-2 5/19/05 10:30 AM Page 14

3-35
STEERING HEAD INSPECTION AND ADJUSTMENT
INSP
ADJ
2. Inspect:
9Bearing free play
Exist play Replace.
EC36U070
STEERING HEAD INSPECTION AND
ADJUSTMENT
1. Elevate the front wheel by placing a suitable
stand under the engine.
2. Check:
9Steering shaft
Grasp the bottom of the forks and gently
rock the fork assembly back and forth.
Free play Adjust steering head.
3. Check:
9Steering smooth action
Turn the handlebar lock to lock.
Unsmooth action Adjust steering ring
nut.
4. Adjust:
9Steering ring nut
Steering ring nut adjustment steps:
9Remove the number plate.
9Remove the handlebar and handle crown.
9Loosen the ring nut 1using the ring nut
wrench 2.
9Tighten the ring nut 3using ring nut wrench
4.
NOTE:
9Apply the lithium soap base grease on the
thread of the steering shaft.
9Set the torque wrench to the ring nut wrench
so that they form a right angle.
Ring nut wrench:
YU-33975/90890-01403
1P8-9-31-3B 5/13/05 11:44 AM Page 34

10. Tighten:
9Base valve 1
NOTE:
Hold the damper assembly with the cap bolt
ring wrench
2and use the cap bolt wrench 3
to tighten the base valve with specified torque.
11. After filling, pump the damper assembly 1
slowly up and down more than 10 times to
distribute the fork oil.
5-35
CHASFRONT FORK
12. While protecting the damper assembly 1
with a rag and compressing fully, allow
excessive oil to overflow on the base valve
side.
cC
Take care not to damage the damper
assembly.
13. Allow the overflowing oil to escape at the
hole ain the damper assembly.
14. Check:
9Damper assembly smooth movement
Tightness/Binding/Rough spots  Repeat
the steps 2 to 13.
29 Nm (2.9 m•kg, 21 ft•lb)
Cap bolt wrench:
YM-01500/90890-01500
Cap bolt ring wrench:
YM-01501/90890-01501
1P8-9-31-5B 5/12/05 10:57 AM Page 20

5-39
CHASFRONT FORK
27. Install:
9Push rod 1
9Copper washer 2
9Adjuster 3
To damper assembly 4.
NOTE:
9While compressing the inner tube 5, set the
cap bolt ring wrench 7between the inner tube
and locknut 6.
9Fully finger tighten the adjuster onto the
damper assembly.
28. Inspect:
9Gap abetween adjuster 1and locknut 2.
Out of specificationRetighten and read-
just the locknut.
NOTE:
If the adjuster is installed out of specification,
proper damping force cannot be obtained.
29. Tighten:
9Adjuster (locknut) 1
NOTE:
Hold the locknut 2and tighten the adjuster with
specified torque.
30. Install:
9Adjuster 1
To inner tube.
31. Fill:
9Front fork oil 1
From outer tube top.
*For EUROPE
29 Nm (2.9 m•kg, 21 ft•lb)
55 Nm (5.5 m•kg, 40 ft•lb)
Gap a abetween adjuster and locknut :
0.5~1.0mm (0.02~0.04 in)
Recommended oil:
Suspension oil "S1"
Standard oil amount:
340 cm
3(12.0 Imp oz, 11.5 US oz)
*345 cm
3(12.1 Imp oz, 11.7 US oz)
Extent of adjustment:
300
~380 cm3(10.6~13.4 Imp oz,
10.1~12.8 US oz)
Cap bolt ring wrench:
YM-01501/90890-01501
1P8-9-31-5B 9/12/05 2:51 PM Page 28

5-40
CHASFRONT FORK
32. Install:
9Damper assembly 1
To outer tube.
NOTE:
Temporarily tighten the damper assembly.
33. Install:
9Protector guide 1
NOTE:
Install the protector guide with its wider side a
facing downward.
EC5552A1
Installation
1. Install:
9Front fork 1
NOTE:
9Temporarily tighten the pinch bolts (under
bracket).
9Do not tighten the pinch bolts (handle crown)
yet.
2. Tighten:
9Damper assembly 1
NOTE:
Use the cap bolt ring wrench 2to tighten the
damper assembly with specified torque.
w
Never fail to make the oil amount adjustment
between the maximum and minimum
amount and always adjust each front fork to
the same setting. Uneven adjustment can
cause poor handling and loss of stability.
cC
9Be sure to use recommended fork oil. If
other oils are used, they may have an ex-
cessively adverse effect on the front fork
performance.
9Never allow foreign materials to enter the
front fork.
30 Nm (3.0 m•kg, 22 ft•lb)
Cap bolt ring wrench:
YM-01501/90890-01501
1P8-9-31-5B 5/12/05 10:57 AM Page 30

5-41
CHASFRONT FORK
6. Adjust:
9Rebound damping force
NOTE:
Turn in the damping adjuster 1finger-tight and
then turn out to the originally set position.
5. Install:
9Protector 1
9Bolt (protector) 2
7 Nm (0.7 m•kg, 5.1 ft•lb)
3. Adjust:
9Front fork top end a
Front fork top end (standard) a a
:
Zero mm (Zero in)
4. Tighten:
9Pinch bolt (handle crown) 1
9Pinch bolt (under bracket) 2
cC
Tighten the under bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
23 Nm (2.3 m•kg, 17 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
7. Adjust:
9Compression damping force
NOTE:
Turn in the damping adjuster 1finger-tight and
then turn out to the originally set position.
1P8-9-31-5B 5/12/05 10:57 AM Page 32

5-54
CHASSTEERING
11. Adjust:
9Front fork top end a
12. Tighten:
9Pinch bolt (handle crown) 1
9Pinch bolt (under bracket) 2
cC
Tighten the under bracket to specified
torque. If torqued too much, it may cause
the front fork to malfunction.
Front fork top end (standard) a a
:
Zero mm (Zero in)
23 Nm (2.3 m•kg, 17 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
9. Install:
9Steering shaft cap 1
10. After tightening the nut, check the steering for
smooth movement. If not, adjust the steering
by loosening the ring nut little by little.
1P8-9-31-5C 5/12/05 11:28 AM Page 26

7-22
SETTINGTUN
EC72H010
Suspension setting
9Front fork
NOTE:
9If any of the following symptoms is experienced with the standard position as the base, make reset-
ting by reference to the adjustment procedure given in the same chart.
9Before any change, set the rear shock absorber sunken length to the standard figure 90~100 mm
(3.5~3.9 in).
Section
Symptom
JumpLarge
Medium Small Check Adjust
gap gap gap
Compression damping Turn adjuster counterclockwise (about 2 clicks)
Stiff over entire to decrease damping.
range111Oil amount Decrease oil amount by about 5~10 cm
3(0.2~0.4
Imp oz, 0.2~0.3 US oz).
Spring Replace with soft spring.
Outer tube Check for any bends, dents, and other notice-
Unsmooth Inner tube able scars, etc. If any, replace affected parts.
movement over 1111Slide metal Replace with a new one for extended use.
entire rangePiston metal Replace with a new one for extended use.
Under bracket tightening Retighten to specified torque.
torque
Poor initial Rebound damping Turn adjuster counterclockwise (about 2 clicks)
movement1to decrease damping.
Oil seal Apply grease in oil seal wall.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
Soft over entire crease damping.
range, bottoming 11Oil amount Increase oil amount by about 5~10 cm
3(0.2~0.4
outImp oz, 0.2~0.3 US oz).
Spring Replace with stiff spring.
Stiff toward stroke
1Oil amountDecrease oil amount by about 5 cm
3(0.2 Imp oz,
end0.2 US oz).
Soft toward stroke
1Oil amountIncrease oil amount by about 5 cm
3(0.2 Imp oz,
end, bottoming out 0.2 US oz).
Stiff initial
1111Compression dampingTurn adjuster counterclockwise (about 2 clicks)
movement to decrease damping.
Compression damping Turn adjuster clockwise (about 2 clicks) to in-
crease damping.
Low front, tending Rebound damping Turn adjuster counterclockwise (about 2 clicks)
to lower front 11to decrease damping.
postureBalance with rear end Set sunken length for 95~100 mm (3.7~3.9 in)
when one passenger is astride seat (lower rear
posture).
Oil amount Increase oil amount by about 5 cm
3(0.2 Imp oz,
0.2 US oz).
Compression damping Turn adjuster counterclockwise (about 2 clicks)
to decrease damping.
“Obtrusive” front, Balance with rear end Set sunken length for 90~95 mm (3.5~3.7 in)
tending to upper 11when one passenger is astride seat (upper rear
front postureposture).
Spring Replace with soft spring.
Oil amount Decrease oil amount by about 5~10 cm
3(0.2~0.4
Imp oz, 0.2~0.3 US oz).
1P8-9-31-7 5/19/05 1:31 PM Page 48