2001 YAMAHA YZ250LC clutch

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
P7-1~24
results of test runs before racing? Are inspection and
maintenance completely done?
5MW-9-30-3A 7/3/00 2:47 PM Page 14

INSP
ADJ
3-9
CLUTCH ADJUSTMENT
NOTE:
9Do not apply pressure more than specified
pressure.
9Radiator should be filled fully.
4. Inspect:
9Pressure
Impossible to maintain the specified pres-
sure for 10 secondsÕRepair.
9Radiator 1
9Radiator hose joint 2
Coolant leakageÕRepair or replace.
9Radiator hose 3
SwellingÕReplace.
2. Adjust:
9Clutch lever free play
EC359020
CLUTCH ADJUSTMENT
1. Check:
9Clutch lever free play a
Out of specificationÕAdjust.
NOTE:
9Make minute adjustment on the lever side
using the adjuster 3.
9After adjustment, check proper operation of
clutch lever.
Clutch lever free play a a
:
2~4 mm (0.08~0.16 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.
5MW-9-30-3A 7/3/00 2:49 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 endUse Yamaha cable lube or equivalent on
these areas.
õUse SAE10W-30 motor oil or suitable chain
lubricants.
‚Lubricate the following areas with high quali-
ty, lightweight lithium-soap base grease.
cC
Wipe off any excess grease, and avoid getting
grease on the brake discs.
A
A
CC
AB
AA
5MW-9-30-3B 7/3/00 3:30 PM Page 42

4-32
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)
5MW-9-30-4B 7/3/00 6:27 PM Page 12

4-33
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 Push rod 2 1
6 Nut (clutch boss) 1
Use special tool.
7
Lock washer1
Refer to “REMOVAL POINTS”.
8 Clutch boss 1
9
Thrust plate [D=ø44mm (1.73 in)]1
10 Primary driven gear 1
11 Bearing 1
12
Thrust plate [D=ø42mm (1.65 in)]1
13 Bolt (push lever axle) 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
ü
ï
ý
ï
þ
3
75 Nm (7.5 m•kg, 54 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
5MW-9-30-4B 7/3/00 6:28 PM Page 14

4-34
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.
ŒFor USA and CDN
ºExcept for USA and CDN
EC494000
INSPECTION
EC484100
Clutch housing and boss
1. Inspect:
9Clutch housing 1
Cracks/Wear/Damage Õ Replace.
9Clutch boss 2
Scoring/Wear/Damage ÕReplace.
EC484201
Primary driven gear
1. Check:
9Circumferential play
Free play exists ÕReplace.
9Gear teeth a
Wear/ Damage ÕReplace.
EC484400
Clutch spring
1. Measure:
9Clutch spring free length a
Out of specification ÕReplace springs as
a set.
Clutch holding tool:
YM-91042................................4 4
90890-04086............................5 5
Clutch spring free length:
Standard
44.0 mm 42.0 mm
(1.732 in) (1.654 in)
Œ
ºŒ
5MW-9-30-4B 7/3/00 6:29 PM Page 16

4-35
CLUTCH AND PRIMARY DRIVEN GEARENG
EC484500
Friction plate
1. Measure:
9Friction plate thickness
Out of specification ÕReplace friction
plate as a set.
Measure at all four points.
EC484600
Clutch plate
1. Measure:
9Clutch plate warpage
Out of specification ÕReplace 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 ÕReplace.
EC484810
Push rod
1. Inspect:
9Push rod 1 1
9Bearing 2
9Plain washer 3
9Push rod 2 4
Wear/Damage/Bend ÕReplace.
EC495000
ASSEMBLY AND INSTALLATION
EC485120
Push lever axle
1. Install:
9Push lever axle 1
9Copper washer 2
9Bolt (push lever axle) 3
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)
6 Nm (0.6 m•kg, 4.3ft•lb)
5MW-9-30-4B 7/3/00 6:30 PM Page 18

4-36
CLUTCH AND PRIMARY DRIVEN GEARENG
EC495230
Clutch
1. Install:
9Thrust plate [D=ø 42 mm (1.65 in)] 1
9Spacer 2
9Bearing 3
9Primary driven gear 4
NOTE:
Apply the transmission oil on the bearing, spacer
and primary driven gear inner circumference.
2. Install:
9Thrust plate [D=ø 44 mm (1.73 in)] 1
9Clutch boss 2
3. Install:
9Lock washer 1
9Nut (clutch boss) 2
NOTE:
Use the clutch holding tool 3, 4to hold the
clutch boss.
ŒFor USA and CDN
ºExcept for USA and CDN
4. Bend the lock washer 1tab.
75 Nm (7.5 m•kg, 54 ft•lb)
Clutch holding tool:
YM-91042 ..............................3 3
90890-04086 ..........................4 4
Œ
º
5MW-9-30-4B 7/3/00 6:31 PM Page 20