Shock YAMAHA YZ250LC 2004 User Guide

3-30
REAR SHOCK ABSORBER SPRING PRELOAD
ADJUSTMENTINSP
ADJ
EC36M014
REAR SHOCK ABSORBER SPRING
PRELOAD ADJUSTMENT
1. Elevate the rear wheel by placing the suit-
able stand under the engine.
2. Remove:
9Rear frame
3. Loosen:
9Locknut 1
4. Adjust:
9Spring preload
By turning the adjuster 2.
NOTE:
9Be sure to remove all dirt and mud from around
the locknut and adjuster before
adjustment.
9The length of the spring (installed) changes 1.5
mm (0.06 in) per turn of the adjuster.
cC
Never attempt to turn the adjuster beyond
the maximum or minimum setting.
5. Tighten:
9Locknut
6. Install:
9Rear frame (upper)
9Rear frame (lower)
Stiffer Increase the spring preload.
(Turn the adjuster 2 2
in.)
Softer Decrease the spring pre-
load. (Turn the adjuster 2 2
out.)
Extent of adjustment
240.5~258.5 mm
(9.47~10.18 in)
*255.5~273.5 mm
(10.06~10.77 in)
Spring length (installed) a a
:
Standard length
245 mm (9.65 in)
*268 mm (10.55 in)
*For EUROPE
32 Nm (3.2 m•kg, 23 ft•lb)
29 Nm (2.9 m•kg, 21 ft•lb)
5XF-9-30-3B 5/6/03 6:31 PM Page 24

3-31
REAR SHOCK ABSORBER REBOUND DAMPING
FORCE ADJUSTMENTINSP
ADJ
EC36N014
REAR SHOCK ABSORBER REBOUND
DAMPING FORCE ADJUSTMENT
1. Adjust:
9Rebound damping force
By turning the adjuster 1.
9STANDARD POSITION:
This is the position which is back by the specif-
ic number of clicks from the fully turned-in posi-
tion. (Which align the punch mark aon the ad-
juster with the punch mark bon the bracket.)
*For EUROPE
cC
Do not force the adjuster past the mini-
mum or maximum extent of adjustment.
The adjuster may be damaged.
Stiffer a a
Increase the rebound damping
force. (Turn the adjuster 1 1
in.)
Softer b b
Decrease the rebound
damping force. (Turn the ad-
juster 1 1
out.)
Minimum
20 clicks out
(from maximum
position)
Extent of adjustment:
Maximum
Fully turned in
position
Standard position:
About 12 clicks out
*About 11 clicks out
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3-32
REAR SHOCK ABSORBER LOW COMPRESSION
DAMPING FORCE ADJUSTMENTINSP
ADJ
EC36c000
REAR SHOCK ABSORBER LOW
COMPRESSION DAMPING FORCE
ADJUSTMENT
1. Adjust:
9Low compression damping force
By turning the adjuster 1.
9STANDARD POSITION:
This is the position which is back by the specif-
ic number of clicks from the fully turned-in posi-
tion. (Which align the punch mark aon the ad-
juster with the punch mark bon the high com-
pression damping adjuster.)
cC
Do not force the adjuster past the mini-
mum or maximum extent of adjustment.
The adjuster may be damaged.
Stiffer a a
Increase the low compression
damping force. (Turn the ad-
juster 1 1
in.)
Softer b b
Decrease the low compres-
sion damping force. (Turn
the adjuster 1 1
out.)
Minimum
20 clicks out
(from maximum
position)
Extent of adjustment:
Maximum
Fully turned in
position
Standard position:
About 12 clicks out
5XF-9-30-3B 5/6/03 6:31 PM Page 28

3-33
REAR SHOCK ABSORBER HIGH COMPRESSION
DAMPING FORCE ADJUSTMENTINSP
ADJ
EC36d000
REAR SHOCK ABSORBER HIGH
COMPRESSION DAMPING FORCE
ADJUSTMENT
1. Adjust:
9High compression damping force
By turning the adjuster 1.
9STANDARD POSITION:
This is the position which is back by the specif-
ic number of turns from the fully turned-in posi-
tion. (Which align the punch mark aon the ad-
juster with the punch mark bon the adjuster
body.)
cC
Do not force the adjuster past the mini-
mum or maximum extent of adjustment.
The adjuster may be damaged.
Stiffer a a
Increase the high compression
damping force. (Turn the ad-
juster 1 1
in.)
Softer b b
Decrease the high compres-
sion damping force. (Turn
the adjuster 1 1
out.)
Minimum
2 turns out
(from maximum
position)
Extent of adjustment:
Maximum
Fully turned in
position
Standard position:
About 1-1/8 turns out
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5-24
CHASFRONT BRAKE AND REAR BRAKE
2. Install:
9Brake hose holder 1
9Screw (brake hose holder) 2
cC
After installing the brake hose holders,
make sure the brake hose does not contact
the spring (rear shock absorber). If it does,
correct its twist.
EC5A5620
Brake fluid
1. Fill:
9Brake fluid
Until the fluid level reaches “LOWER” level
line a.
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9Use only the designated quality brake fluid:
otherwise, the rubber seals may deterio-
rate, causing leakage and poor brake per-
formance.
9Refill with the same type of brake fluid;
mixing fluids may result in a harmful chemi-
cal reaction and lead to poor performance.
9Be careful that water does not enter the
master cylinder when refilling. Water will
significantly lower the boiling point of the
fluid and may result in vapor lock.
cC
Brake fluid may erode painted surfaces or
plastic parts. Always clean up spilled fluid
immediately.
AFront
BRear
Recommended brake fluid:
DOT #4
1 Nm (0.1 m•kg, 0.7 ft•lb)
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5-51
CHASSWINGARM
Extent of removal Order Part name Q’ty Remarks
SWINGARM REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Brake hose holderRefer to “FRONT BRAKE AND
Rear caliperREAR BRAKE”section.
Bolt (brake pedal) Shift the brake pedal backward.
Drive chain
1 Chain support 1
2 Chain tensioner (lower) 1
3
Bolt (rear shock absorber-relay arm)1 Hold the swingarm.
4 Bolt (connecting rod) 1
5 Pivot shaft 1
6 Swingarm 1 Extent of removal:
1Swingarm removal
1
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Support the machine securely so there is no dan-
ger of it falling over.



EC570000
SWINGARM
53 Nm (5.3 m•kg, 38 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
85 Nm (8.5 m•kg, 61 ft•lb)
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5-57
CHASSWINGARM
10. Tighten:
9Nut (connecting rod) 1
11. Tighten:
9Nut (relay arm) 1
80 Nm (8.0 m•kg, 58 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
8. Install:
9Bolt (connecting rod) 1
9Plain washer 2
9Nut (connecting rod) 3
NOTE:
9Apply the molybdenum disulfide grease on the
bolt.
9Do not tighten the nut yet.
9. Install:
9Bolt (rear shock absorber-relay arm) 1
9Nut (rear shock absorber-relay arm) 2
NOTE:
Apply the molybdenum disulfide grease on the
bolt.
53 Nm (5.3 m•kg, 38 ft•lb)
7. Check:
9Swingarm side play
a
Free play exists  Replace thrust bearing.
9Swingarm up and down movement b
Unsmooth movement/Binding/Rough
spotsGrease or replace bearings, bushes
and collars.
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5-59
CHASREAR SHOCK ABSORBER
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER
REMOVAL
Preparation forHold the machine by placing the
removalsuitable stand under the engine.
SeatRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
SilencerRefer to “EXHAUST PIPE AND
SILENCER” section.
1 Clamp (air cleaner joint) 1 Loosen the screw (air cleaner joint).
2 Rear frame 1
3
Bolt (rear shock absorber-relay arm)1 Hold the swingarm.
4 Bolt (rear shock absorber-frame) 1
5 Rear shock absorber 1
6 Locknut 1
7 Adjuster 1
8 Spring guide (lower) 1
9 Spring guide (upper) 1
10 Spring (rear shock absorber) 1
11 Bearing 2 Refer to “REMOVAL POINTS”.
2
w
Support the machine securely so there is no dan-
ger of it falling over.
Extent of removal:1Rear shock absorber removal 2Rear shock absorber disassembly
1
56 Nm (5.6 m•kg, 40 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
32 Nm (3.2 m•kg, 23 ft•lb)
EC580000
REAR SHOCK ABSORBER
29 Nm (2.9 m•kg, 21 ft•lb)
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5-60
CHASREAR SHOCK ABSORBER
EC586000
HANDLING NOTE
w
This shock absorber is provided with a
separate type tank filled with high-pressure
nitrogen gas. To prevent the danger of ex-
plosion, read and understand the following
information before handling the shock ab-
sorber.
The manufacturer can not be held respon-
sible for property damage or personal in-
jury that may result from improper han-
dling.
1. Never tamper or attempt to disassemble
the cylinder or the tank.
2. Never throw the shock absorber into an
open flame or other high heat. The shock
absorber may explode as a result of ni-
trogen gas expansion and/or damage to
the hose.
3. Be careful not to damage any part of the
gas tank. A damaged gas tank will impair
the damping performance or cause a
malfunction.
4. Take care not to scratch the contact sur-
face of the piston rod with the cylinder;
or oil could leak out.
5. Never attempt to remove the plug at the
bottom of the nitrogen gas tank. It is very
dangerous to remove the plug.
6. When scrapping the shock absorber, fol-
low the instructions on disposal.
EC587000
NOTES ON DISPOSAL (YAMAHA DEAL-
ERS ONLY)
Before disposing the shock absorber, be sure to
extract the nitrogen gas from valve 1. Wear eye
protection to prevent eye damage from escaping
gas and/or metal chips.
w
To dispose of a damaged or worn-out
shock absorber, take the unit to your
Yamaha dealer for this disposal procedure.
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5-61
CHASREAR SHOCK ABSORBER
EC583000
REMOVAL POINTS
EC583320
Bearing
1. Remove:
9Stopper ring (upper bearing) 1
NOTE:
Press in the bearing while pressing its outer race
and remove the stopper ring.
2. Remove:
9Upper bearing 1
NOTE:
Remove the bearing by pressing its outer race.
EC584000
INSPECTION
EC584110
Rear shock absorber
1. Inspect:
9Damper rod 1
Bends/Damage Replace absorber
assembly.
9Shock absorber 2
Oil leaks Replace absorber assembly.
Gas leaks Replace absorber assembly.
9Spring 3
Damage Replace spring.
Fatigue Replace spring.
Move spring up and down.
9Spring guide 4
Wear/Damage Replace spring guide.
9Bearing 5
Free play exists/Unsmooth revolution/
Rust Replace. 3. Remove:
9Lower bearing 1
NOTE:
Remove the bearing by pressing its outer race.
5XF-9-30-5D 5/6/03 6:37 PM Page 22