2005 YAMAHA YZ125LC engine

4-63
ENGCRANKCASE AND CRANKSHAFT
EC4N3302
Crankshaft
1. Remove:
9Crankshaft 1
Use the crankcase separating tool 2.
NOTE:
Make appropriate bolts 3as shown available by
yourself and attach the tool with them.
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 å.
9If the bearing is removed together with the
crankshaft, remove the bearing using a general
bearing puller 2as shown in ∫.
9Do not use the removed bearing.
EC4N4000
INSPECTION
EC4N4101
Crankcase
1. Inspect:
9Contacting surface a
Scratches Replace.
9Engine mounting boss b, crankcase
Cracks/Damage Replace.
Crankcase separating tool:
YU-1135-A/90890-01135
1C3-9-30-4D 25/5/04 7:15 PM Page 16

8. 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.
9. Remove:
9Sealant
Forced out on the cylinder mating surface.
10. Apply:
9Engine oil
To the crank pin, bearing, oil delivery hole
and connecting rod big end washer.
11. Check:
9Crankshaft and transmission operation
Unsmooth operation Repair.
4-68
ENGCRANKCASE AND CRANKSHAFT
30 Nm (3.0 m•kg, 22 ft•lb)
1C3-9-30-4D 25/5/04 7:15 PM Page 26

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”.
9 Spacer 1
EC4H0000
TRANSMISSION, SHIFT CAM AND SHIFT FORK
Extent of removal:1Shift cam and shift fork removal2Main axle and drive axle removal
1
2



10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
1C3-9-30-4D 25/5/04 7:15 PM Page 28

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 Bolt (axle holder) 4 Only loosening.
2 Nut (front wheel axle) 1
3 Front wheel axle 1
4 Front wheel 1
5 Collar 2
6 Oil seal 2
7 Bearing 2 Refer to “REMOVAL POINTS”.
8 Brake disc 1
EC500000
CHASSISEC590000
FRONT WHEEL AND REAR WHEELEC598000
FRONT WHEEL
2
13
3
Extent of removal:1Front wheel removal2Wheel bearing removal3Brake disc removal
w
Support the machine securely so there is no dan-
ger of it falling over.
23 Nm (2.3 m•kg, 17 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
1C3-9-30-5A 17/5/04 1:41 PM Page 2

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 disc 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)
16 Nm (1.6 m•kg, 11 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
1C3-9-30-5A 17/5/04 1:41 PM Page 4

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 Brake hose holder (protector) 2
2 Brake hose holder (caliper) 1
3 Union bolt 2
4 Brake hose 1
5 Pad pin plug 1
Remove when loosening the pad pin.
6 Pad pin 1Loosen when disassembling the caliper.
7 Caliper 1
8 Brake lever 1
9 Master cylinder bracket 1
10 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
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)
10 Nm (1.0 m•kg, 7.2 ft•lb)
3 Nm (0.3 m•kg, 2.2 ft•lb)
18 Nm (1.8 m•kg, 13 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
2
6 Nm (0.6 m•kg, 4.3 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
1C3-9-30-5A 17/5/04 1:41 PM Page 20

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 Brake pedal 1
2 Master cylinder 1
3 Brake hose holder 2
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
Extent of removal:1Master cylinder removal2Brake hose removal3Caliper removal
w
Support the machine securely so there is no dan-
ger of it falling over.
2
3
31
1
1 Nm (0.1 m•kg, 0.7 ft•lb)
30 Nm (3.0 m•kg, 22 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)
7 Nm (0.7 m•kg, 5.1 ft•lb)
1C3-9-30-5A 17/5/04 1:41 PM Page 22

5-26
CHASFRONT FORK
Extent of removal Order Part name Q’ty Remarks
FRONT FORK REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Front wheel Refer to “FRONT WHEEL AND
REAR WHEEL”section.
Front caliper Refer to “FRONT BRAKE AND
REAR BRAKE”section.
Number plate
1 Protector 1
2 Pinch bolt (handle crown) 2 Only loosening.
3 Damper assembly 1
Loosen when disassembling the front fork.
Use special tool. Refer to “REMOVAL POINTS”.
4 Pinch bolt (under bracket) 2 Only loosening.
5 Front fork 1
1
w
Support the machine securely so there is no dan-
ger of it falling over.
Extent of removal:1Front fork removal
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
23 Nm (2.3 m•kg, 17 ft•lb)
EC550000
FRONT FORK
1C3-9-30-5B 28/5/04 9:07 AM Page 2