2002 YAMAHA YZ125LC brake

5-42
CHASHANDLEBAR
EC5B3000
REMOVAL POINTS
EC5B3100Master cylinder
1. Remove:
9Master cylinder bracket 1
9Master cylinder 2
cC
9
Do not let the master cylinder hang on the
brake hose.
9Keep the master cylinder cap side horizon-
tal to prevent air from coming in.
EC5B3200
Grip
1. Remove:
9Grip 1
NOTE:
Blow in air between the handlebar or tube guide
and the grip. Then remove the grip which has
become loose.
EC5B4000
INSPECTION
EC5B4100
Handlebar
1. Inspect:
9Handlebar 1
Bends/Cracks /DamageReplace.
w
Do not attempt to straighten a bent handlebar
as this may dangerously weaken the handlebar.
EC5B5000
ASSEMBLY AND INSTALLATION
EC5B5100
Throttle assembly
1. Install
9Grip (right) 1
Apply the adhesive on the tube guide 2.
NOTE:
9Before applying the adhesive, wipe off grease
or oil on the tube guide surface awith a lac-
quer thinner.
9Align the mating mark bon the grip (right)
with the slot cin the tube guide.
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5-45
CHASHANDLEBAR
10. Install:
9Bolt (grip cap) 1
w
9
Install the grip cap so that the gaps a a
and
b b
between the bolt (grip cap) and brake
lever 2 2
are equal. If you make a mistake in
the grip cap installation position, the brake
lever may contact the grip cap, resulting in
poor brake performance.
9After tightening the bolts, check that the
throttle grip 3 3
moves smoothly. If it does
not, retighten the bolts for adjustment.
11. Install:
9“ENGINE STOP” button 1
9Clutch lever holder 2
9Bolt (clutch lever holder) 3
9Clamp 4
NOTE:
9The “ENGINE STOP” button, clutch lever hold-
er and clamp should be installed according to
the dimensions shown.
9Pass the “ENGINE STOP” button lead in the
middle of the clutch holder.
12. Install:
9Clutch cable 1
NOTE:
Apply the lithium soap base grease on the clutch
cable end.
13. Adjust:
9Clutch lever free play
Refer to “CLUTCH ADJUSTMENT” section in
the CHAPTER 3.
4 Nm (0.4 m•kg, 2.9 ft•lb)
4 Nm (0.4 m•kg, 2.9 ft•lb)
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5-52
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
EC570000
SWINGARM
Extent of removal:1Swingarm removal
1
w
Support the machine securely so there is no dan-
ger of it falling over.



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)
5NY-9-30-5D 5/23/01 9:14 PM Page 2

7-11
TUNSETTING
Symptom Setting Checking
0~1/4 throttle Use jet needle having a smaller Number of turns-back 
* Hard breathing diameter. Correct properly
Speed down Overflow from carburetor
0~1/4 throttle Use jet needle having a larger
Poor acceleration diameter.
White smoke
Unstable at low speeds Lower jet needle clip position.
Pinking noise (1 groove down)
Turn in pilot air screw.
Poor response at extremely Reduce pilot jet calibration No. Dragging brake
low speed Turn out pilot air screw. Overflow from carburetor
If not effect, reverse the
above procedures.
Poor response in Raise jet needle clip position.
the range of low to If no effect, reverse the above
intermediate speeds procedures.
Poor response when Check overall settings. Check air cleaner for fouling.
throttle is opened quickly Use main jet having lower
calibration No.
Raise jet needle clip position.
(1 groove up)
If no effect, reverse the above
procedures.
Poor engine operation Turn in pilot air screw. Check throttle valve operation.
This should be taken simply for an example.
It is necessary to set the carburetor while
checking the operating conditions of the
engine and discoloration of spark plugs.
Normally, carburetor setting is made by
means of the main jet, jet needle clip position
(including one with 0.5 difference), pilot jet
and pilot air screw. If the result of setting is
still unsatisfactory, it is advisable to change
the diameter of the straight portion the jet
needle.
*In case of hard breathing, check the air vent hose for clogging.
5NY-9-30-7A 5/23/01 9:19 PM Page 25