engine YAMAHA YZ125LC 2001 Repair Manual

4-61
ENGENGINE REMOVAL
2. Install:
9Lock washer 1
9Nut (drive sprocket) 2
NOTE:
Tighten the nut while applying the rear brake.
3. Bend the lock washer tab to lock the nut.
4. Install:
9Chain cover 1
9Screw (chain cover) 2
5 Nm (0.5 m•kg, 3.6 ft•lb)
60 Nm (6.0 m•kg, 43 ft•lb)
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4-62
ENGCRANKCASE AND CRANKSHAFT
Extent of removal Order Part name Q’ty Remarks
CRANKCASE AND CRANKSHAFT
REMOVAL
Preparation for Engine Refer to “ENGINE REMOVAL”section.
removal Piston Refer to “
CYLINDER HEAD, CYLINDER
AND PISTON
” section.
Primary drive gear
Kick idle gearRefer to “
KICK AXLE, SHIFT SHAFT AND
Stopper leverPRIMARY DRIVE GEAR”section.
Rotor and stator Refer to “CDI MAGNETO” section.
1 Segment 1 Refer to “REMOVAL POINTS”.
2 Bolt [L=50 mm (1.97 in)] 4
3 Bolt [L=60 mm (2.36 in)] 6
4 Bolt [L=70 mm (2.76 in)] 2
5 Holder 1
6 Crankcase (right) 1 Use special tool.
7 Crankcase (left) 1 Refer to “REMOVAL POINTS”.
8 Crankshaft 1 Use special tool.
Refer to “REMOVAL POINTS”.
9 Oil seal 2
10 Bearing 2 Refer to “REMOVAL POINTS”.
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EC4N0000
12
3
Extent of removal:1Crankcase separation2Crankshaft removal
3Crankshaft bearing removal
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30 Nm (3.0 m•kg, 22 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
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4-63
ENGCRANKCASE AND CRANKSHAFT
EC4N3000
REMOVAL POINTS
EC4N3100
Segment
1. Remove:
9Bolt (segment) 1
9Segment 2
NOTE:
Turn the segment counterclockwise until it stops
and loosen the bolt.
EC4N3211
Crankcase
1. Remove:
9Crankcase (right) 1
Use the crankcase separating tool 2and
crankcase separating bolt 3.
NOTE:
9Fully tighten the tool holding bolts, but make
sure the tool body is parallel with the case. If
necessary, one screw may be backed out
slightly to level tool body.
9As pressure is applied, alternately tap on the
front engine mounting boss and transmission
shafts.
cC
Use soft hammer to tap on the case half.
Tap only on reinforced portions of case. Do
not tap on gasket mating surface. Work
slowly and carefully. Make sure the case
halves separate evenly. If one end “hangs
up”, take pressure off the push screw, re-
align, and start over. If the cases do not
separate, check for a remaining case
screw or fitting. Do not force.
Crankcase separating tool:
YU-1135-A/90890-01135
Crankcase separating bolt:
YM-1305/90890-01305
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4-64
ENGCRANKCASE AND CRANKSHAFT
EC4N3301
Crankshaft
1. Remove:
9Crankshaft 1
Use the crankcase separating tool 2and
crankcase separating bolt 3.
cC
Do not use a hammer to drive out the
crankshaft.
EC4N3401
Crankshaft bearing
1. Remove:
9Bearing 1
NOTE:
9Remove the bearing from the crankcase by
pressing its inner race as shown in Œ.
9If the bearing is removed together with the
crankshaft, remove the bearing using a general
bearing puller 2as shown in º.
9Do not use the removed bearing.
EC4N4000
INSPECTION
EC4N4101
Crankcase
1. Inspect:
9Contacting surface a
Scratches ÕReplace.
9Engine mounting boss b, crankcase
Cracks/Damage ÕReplace.
Crankcase separating tool:
YU-1135-A/90890-01135
Crankcase separating bolt:
YM-1305/90890-01305
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4-68
ENGCRANKCASE AND CRANKSHAFT
6. Install:
9Holder 1
9Bolt (holder) 2
7. Install:
9Segment 1
9Bolt (segment) 2
NOTE:
9When installing the segment onto the shift cam
3, align the punch mark awith the dowel pin
b.
9Turn the segment clockwise until it stops and
tighten the bolt.
8. Remove:
9Sealant
Forced out on the cylinder mating surface.
9. Apply:
9Engine oil
To the crank pin, bearing, oil delivery hole
and connecting rod big end washer.
10. Check:
9Crankshaft and transmission operation
Unsmooth operation ÕRepair.
30 Nm (3.0 m•kg, 22 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
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4-69
ENGTRANSMISSION, SHIFT CAM AND SHIFT FORK
Extent of removal Order Part name Q’ty Remarks
TRANSMISSION, SHIFT CAM AND
SHIFT FORK REMOVAL
Preparation for EngineRefer to “ENGINE REMOVAL” section.
removal Separate the crankcase. Refer to“CRANKCASE AND CRANK
SHAFT
” section.
1 Guide bar (long) 1
2 Guide bar (short) 1
3 Shift cam 1
4 Shift fork 3 1
5 Shift fork 1 1
6 Shift fork 2 1
7 Main axle 1
8 Drive axle 1Refer to “REMOVAL POINTS”.
EC4H0000
Extent of removal:1Shift cam and shift fork removal2Main axle and drive axle removal
1
2
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10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
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5-1
CHASFRONT WHEEL AND REAR WHEEL
Extent of removal Order Part name Q’ty Remarks
FRONT WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Hose cover 1
2 Bolt (brake hose holder) 2 Only loosening.
3 Bolt (axle holder) 4 Only loosening.
4 Nut (front wheel axle) 1
5 Front wheel axle 1
6 Front wheel 1
7 Collar 2
8 Oil seal 2
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
EC500000
CHASSISEC590000
FRONT WHEEL AND REAR WHEELEC598000
FRONT WHEEL
2
13
3
Extent of removal:1Front wheel removal2Wheel bearing removal3Break disc removal
w
Support the machine securely so there is no dan-
ger of it falling over.
5
23 Nm (2.3 m•kg, 17 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
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5-2
CHASFRONT WHEEL AND REAR WHEEL
EC598100
REAR WHEEL
Extent of removal:1Rear wheel removal2Wheel bearing removal3Brake disc removal
Extent of removal Order Part name Q’ty Remarks
REAR WHEEL REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
1 Nut (rear wheel axle) 1
2 Rear wheel axle 1
3 Chain puller 2
4 Rear wheel 1 Refer to “REMOVAL POINTS”.
5 Collar 2
6 Driven sprocket 1
7 Oil seal 2
8 Circlip 1
9 Bearing 2 Refer to “REMOVAL POINTS”.
10 Brake disk 1
2
13
3
w
Support the machine securely so there is no dan-
ger of it falling over.
125 Nm (12.5 m•kg, 90 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
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5-10
CHASFRONT BRAKE AND REAR BRAKE
Extent of removal Order Part name Q’ty Remarks
FRONT BRAKE REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Hose cover 1
2 Brake hose holder 1
3 Bolt (brake hose holder) 2 Only loosening.
4 Union bolt 2
5 Brake hose 1
6 Pad pin plug 1
Remove when loosening the pad pin.
7 Pad pin 1Loosen when disassembling the caliper.
8 Caliper 1
9 Brake lever 1
10 Master cylinder bracket 1
11 Master cylinder 1
EC5A0000
FRONT BRAKE AND REAR BRAKEEC5A8000
FRONT BRAKE
Extent of removal:1Brake hose removal2Caliper removal3Master cyilinder removal
w
Support the machine securely so there is no dan-
ger of it falling over.
2
1
3
3
2
9 Nm (0.9 m•kg, 6.5 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)30 Nm (3.0 m•kg, 22 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
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5-11
CHASFRONT BRAKE AND REAR BRAKE
EC5A8100
REAR BRAKE
Extent of removal Order Part name Q’ty Remarks
REAR BRAKE REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Rear wheel Refer to “FRONT WHEEL AND
REAR WHEEL” section.
Drain the brake fluid. Refer to “REMOVAL POINTS”.
1 Pad pin pulg 1
Remove when loosening the pad pin.
2 Pad pin 1Loosen when disassembling the caliper.
3 Caliper 1
4 Brake hose holder 2
5 Union bolt 2
6 Brake hose 1
7 Brake pedal 1
8 Reservoir tank 1
9 Reservoir hose 1
10 Master cylinder 1
Extent of removal:1Caliper removal2Brake hose removal3Master cylinder removal
w
Support the machine securely so there is no dan-
ger of it falling over.
2
1
3
31
4 Nm (0.4 m•kg, 2.9 ft•lb)7 Nm (0.7 m•kg, 5.1 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
26 Nm (2.6 m•kg, 19 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
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