clutch YAMAHA YZ125LC 2005 User Guide

2-15
SPECCABLE ROUTING DIAGRAM
1“ENGINE STOP” button lead
2C.D.I. magneto lead
3Ignition coil lead
4Ground lead
5Positioning tape
6Protection tube
7C.D.I.unit
8Throttle cable
9Clutch cable
0Side core
qRadiator breather hoseAPass the high tension cord to
the left of the radiator hose.
BClamp to the frame the
“ENGINE STOP” button lead
and C.D.I. magneto lead.
Clamp them in front of the radi-
ator fitting boss.
CClamp to the frame the throttle
cable, clutch cable and ignition
coil lead.
DPass the C.D.I. magneto lead
and radiator breather hose
between the frame and the
right side of the radiator.
EInsert the C.D.I. unit band until
it stops at the C.D.I. unit stay.
FPass the C.D.I. magneto lead
and radiator breather hose
between the frame and the
radiator hose.GLocate the clamp ends in the
arrowed range.
1C3-9-30-2B 16/6/04 9:51 AM Page 30

2-17
SPECCABLE ROUTING DIAGRAM
AInstall the brake hose so that its pipe portion
directs as shown and lightly touches the
projection on the master cylinder.
BPass the “ENGINE STOP” button lead in
the middle of the clutch holder.
CClamp the “ENGINE STOP” button lead to
the handlebar to 3 clicks.
DPass the brake hose in front of the number
plate and through the cable guide. 1Brake hose
2Master cylinder
3“ENGINE STOP” button lead
4“ENGINE STOP” button
5Throttle cable
6Clutch cable
7Clamp
8Cable guide
1C3-9-30-2B 27/5/04 4:18 PM Page 34

3-1
MAINTENANCE INTERVALS
INSP
ADJ
EC300000
REGULAR INSPECTION AND ADJUSTMENTS
EC310053
MAINTENANCE INTERVALS
The following schedule is intended as a general guide to maintenance and lubrication. Bear in mind
that such factors as weather, terrain, geographical location, and individual usage will alter the required
maintenance and lubrication intervals. If you are a doubt as to what intervals to follow in maintaining
and lubricating your machine, consult your Yamaha dealer.
Item Remarks
After
break-
inEvery
raceEvery
thirdEvery
fifthAs re-
quired
Inspect crack
Inspect carbon deposits
and eliminate them
Check ring end gap
Inspect carbon deposits
and eliminate them
Check gasket
Inspect score marks
Inspect wear
Inspect carbon deposits
and eliminate them
Inspect housing, friction
plate, clutch plate and
spring
Yamalube 4 (10W-30) or
SAE 10W-30 SE motor oil
Inspect wear
Use chain lube
Chain slack: 48~58 mm
(1.9~2.3 in) PISTON
Inspect and clean

Replace
PISTON RING
Inspect
Replace
PISTON PIN, SMALL END BEARING
Inspect
Replace
CYLINDER HEAD
Inspect and clean
Retighten
CYLINDER
Inspect and clean
Replace
YPVS
Inspect and clean
CLUTCH
Inspect and adjust
Replace
TRANSMISSION
Replace oil
Inspect
Replace bearing
SHIFT FORK, SHIFT CAM, GUIDE BAR
Inspect
ROTOR NUT
Retighten
MUFFLER
Inspect
Clean
Retighten
CRANK
Inspect and clean
CARBURETOR
Inspect, adjust and clean
SPARK PLUG
Inspect and clean
Replace
DRIVE CHAIN
Lubricate, slack, alignment
Replace
1C3-9-30-3A 17/5/04 8:42 PM Page 2

3-4
PRE-OPERATION INSPECTION AND MAINTENANCE
INSP
ADJ
EC320000
PRE-OPERATION INSPECTION AND MAINTENANCE
Before riding for break-in operation, practice or a race, make sure the machine is in good operating
condition.
Before using this machine, check the following points.
EC321000
GENERAL INSPECTION AND MAINTENANCE
Item Routine Page
Coolant Check that coolant is filled up to the radiator filler cap.
Check the cooling system for leakage.P3-5~9
Fuel Check that a fresh mixture of oil and gasoline is filled in
the fuel tank. Check the fuel line for leakage.P1-12
Transmission oil Check that the oil level is correct. Check the crankcase
for leakage.P3-12~14
Gear shifter and clutch Check that gears can be shifted correctly in order and
that the clutch operates smoothly.P3-9
Throttle grip/Housing Check that the throttle grip operation and free play
are correctly adjusted. Lubricate the throttle grip and P3-10~11
housing, if necessary.
Brakes Check the play of front brake and effect of front and
rear brake.P3-17~23
Chain Check chain slack and alignment. Check that the chain
is lubricated properly.P3-24~26
Wheels Check for excessive wear and tire pressure. Check for
loose spokes and have no excessive play.P3-34~35
Steering Check that the handlebar can be turned smoothly and
have no excessive play.P3-35~36
Front forks and Check that they operate smoothly and there is no oil
rear shock absorber leakage.P3-26~33
Cables (wires) Check that the clutch and throttle cables move smooth-
ly. Check that they are not caught when the handlebars —
are turned or when the front forks travel up and down.
Muffler Check that the muffler is tightly mounted and has no
cracks.P3-15~16
Sprocket Check that the driven sprocket tightening bolt is
not loose.P3-24
Lubrication Check for smooth operation. Lubricate if necessary. P3-37
Bolts and nuts Check the chassis and engine for loose bolts and nuts. P1-16
Lead connectors Check that the CDI magneto, CDI unit, and ignition coil
are connected tightly.P1-6
Settings Is the machine set suitably for the condition of the
racing course and weather or by taking into account the
P7-1~23
results of test runs before racing? Are inspection and
maintenance completely done?
1C3-9-30-3A 17/5/04 8:42 PM Page 14

3-9
INSP
ADJ
CLUTCH ADJUSTMENT
4. Inspect:
9Pressure
Impossible to maintain the specified pres-
sure for 10 seconds Repair.
9Radiator 1
9Radiator hose joint 2
Coolant leakage Repair or replace.
9Radiator hose 3
Swelling Replace.
2. Adjust:
9Clutch lever free play
EC359020
CLUTCH ADJUSTMENT
1. Check:
9Clutch lever free play a
Out of specification Adjust.
NOTE:
9Before adjustment, expose the adjuster by
moving the boot 3and cap 4away.
9Make minute adjustment on the lever side
using the adjuster 5.
9After adjustment, check proper operation of
clutch lever.
Clutch lever free play a a
:
8~13 mm (0.31~0.51 in)
Clutch lever free play adjustment steps:
9Loosen the locknut 1.
9Turn the adjuster 2until free play ais with-
in the specified limits.
9Tighten the locknut.
Locknut:
4 Nm (0.4 m•kg, 2.9 ft•lb)
3. Install:
9Cap 1
9Boot 2
NOTE:
Place the tip aof the cap in the boot.
1C3-9-30-3A 17/5/04 8:42 PM Page 26

3-37
LUBRICATION
INSP
ADJ
EC36a042
LUBRICATION
To ensure smooth operation of all components,
lubricate your machine during setup, after break-
in, and after every race.
1All control cable
2Clutch lever pivot
3Shift pedal pivot
4Footrest pivot
5Throttle-to-handlebar contact
6Drive chain
7Throttle roller sliding surface
8Tube guide cable winding portion
9Throttle cable end
0Clutch cable endÅUse Yamaha cable lube or equivalent on
these areas.
ıUse SAE10W-30 motor oil or suitable chain
lubricants.
ÇLubricate the following areas with high quali-
ty, lightweight lithium-soap base grease.
cC
Wipe off any excess grease, and avoid get-
ting grease on the brake discs.
A
A
CC
AB
AA
1C3-9-30-3B 17/5/04 1:22 PM Page 38

4-30
CLUTCH AND PRIMARY DRIVEN GEARENG
Extent of removal Order Part name Q’ty Remarks
CLUTCH PLATE AND
FRICTION PLATE REMOVAL
Preparation for Drain the transmission oil.
Refer to “TRANSMISSION OIL REPLACE-
removalMENT“ section in the CHAPTER 3.
Bolt (brake pedal) Shift the brake pedal downward.
Rotor and stator Refer to
“CDI MAGNETO“section.
Clutch cable Disconnect at engine side.
1 Clutch cover 1
2 Screw (clutch spring) 6
3 Clutch spring 6
4 Pressure plate 1
5 Friction plate 8
6 Clutch plate 7
Extent of removal:1Clutch plate and friction plate removal
EC490000
CLUTCH AND PRIMARY DRIVEN GEAREC498000
CLUTCH PLATE AND FRICTION PLATE
1
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
1C3-9-30-4B 25/5/04 7:20 PM Page 26

4-31
CLUTCH AND PRIMARY DRIVEN GEARENG
Extent of removal Order Part name Q’ty Remarks
PRIMARY DRIVEN GEAR, PUSH
ROD AND PUSH LEVER AXLE
REMOVAL
1 Push rod 1 1
2 Circlip 1
3 Plain washer 1
4
Bearing 1
5 Ball 1
6 Push rod 2 1
7 Nut (clutch boss) 1
Use special tool.
8
Lock washer1
Refer to “REMOVAL POINTS”.
9 Clutch boss 1
10
Plain washer [D=ø34mm (1.34 in)]1
11 Primary driven gear 1
12 Bearing 1
13
Plain washer [D=ø34mm (1.34 in)]1
14 Push lever axle 1
EC498200
PRIMARY DRIVEN GEAR, PUSH ROD AND PUSH LEVER AXLE
Extent of removal:1Push rod and push lever axle removal2Push rod 1 disassembly
3Primary driven gear removal
2
3
1
1
1





3
80 Nm (8.0 m•kg, 58 ft•lb)
1C3-9-30-4B 1/7/04 8:07 PM Page 28

4-32
CLUTCH AND PRIMARY DRIVEN GEARENG
EC493000
REMOVAL POINTS
EC483211
Clutch boss
1. Remove:
9Nut 1
9Lock washer 2
9Clutch boss 3
NOTE:
Straighten the lock washer tab and use the
clutch holding tool 4, 5to hold the clutch boss.
åFor USA and CDN
∫Except for USA and CDN
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
9Clutch housing 1
Cracks/Wear/Damage  Replace.
9Clutch boss 2
Scoring/Wear/Damage Replace.
EC484201
Primary driven gear
1. Check:
9Circumferential play
Free play exists Replace.
9Gear teeth a
Wear/ Damage Replace.
EC484400
Clutch spring
1. Measure:
9Clutch spring free length a
Out of specification Replace springs as
a set.
Clutch holding tool:
YM-91042................................
4 4
90890-04086............................5 5
Clutch spring free length:
Standard
41.2 mm 39.2 mm
(1.622 in) (1.543 in)
å
∫å
1C3-9-30-4B 25/5/04 7:20 PM Page 30

4-33
CLUTCH AND PRIMARY DRIVEN GEARENG
EC484500
Friction plate
1. Measure:
9Friction plate thickness
Out of specification Replace friction
plate as a set.
Measure at all four points.
EC484600
Clutch plate
1. Measure:
9Clutch plate warpage
Out of specification Replace clutch plate
as a set.
Use a surface plate 1and thickness
gauge 2.
EC484700
Push lever axle
1. Inspect:
9Push lever axle 1
Wear/Damage Replace.
EC484810
Push rod
1. Inspect:
9Push rod 1 1
9Bearing 2
9Plain washer 3
9Push rod 2 4
9Ball 5
Wear/Damage/Bend Replace.
EC495000
ASSEMBLY AND INSTALLATION
EC485120
Push lever axle
1. Install:
9Push lever axle 1
NOTE:
Apply the lithium soap base grease on the oil
seal lip and push lever axle.
Friction plate thickness:
Standard
2.9~3.1 mm 2.8 mm
(0.114~0.122 in) (0.110 in)
Warp limit:
0.2 mm (0.008 in)
1C3-9-30-4B 25/5/04 7:20 PM Page 32