2007 YAMAHA YZ125LC ECU

4-56
ENGENGINE REMOVAL
Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Seat and fuel tankRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
Carburetor Refer to “CARBURETOR AND REED
VALVE” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Clutch cable Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Spark plug cap
Disconnect the CDI magneto lead.
EC4M0000
ENGINE REMOVAL
w
Support the machine securely so there is no dan-
ger of it falling over.
26 Nm (2.6 m•kg, 19 ft•lb)
34 Nm (3.4 m•kg, 24 ft•lb)
64 Nm (6.4 m•kg, 46 ft•lb)
85 Nm (8.5 m•kg, 61 ft•lb)
75 Nm (7.5 m•kg, 54 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
64 Nm (6.4 m•kg, 46 ft•lb)
1C3-9-32-4D 5/1/06 10:41 AM Page 2

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.
21 Nm (2.1 m•kg, 15 ft•lb)
21 Nm (2.1 m•kg, 15 ft•lb)
105 Nm (10.5 m•kg, 75 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
1C3-9-32-5A 4/7/06 2:44 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
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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)
19 Nm (1.9 m•kg, 13 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
1C3-9-32-5A 4/7/06 2:44 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
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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)
1C3-9-32-5A 4/7/06 2:45 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
2 Nm (0.2 m•kg, 1.4 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)
10 Nm (1.0 m•kg, 7.2 ft•lb)
1C3-9-32-5A 4/7/06 2:45 PM Page 22

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
Refer to “SEAT, FUEL TANK AND SIDE
COVERS” section in the CHAPTER 4.
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
5-26
CHASFRONT FORK
1
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Support the machine securely so there is no dan-
ger of it falling over.
Extent of removal:1Front fork removal
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
21 Nm (2.1 m•kg, 15 ft•lb)
21 Nm (2.1 m•kg, 15 ft•lb)
EC550000
FRONT FORK
1C3-9-32-5B 4/7/06 2:47 PM Page 2

5-50
CHASSTEERING
Extent of removal Order Part name Q’ty Remarks
STEERING REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Number plateRefer to “SEAT, FUEL TANK AND SIDE COVERS”
section in the CHAPTER 4.
Handlebar Refer to “HANDLEBAR” section.
Front fender
1 Steering shaft nut 1
2 Front fork 2 Refer to “FRONT FORK” section.
3 Handle crown 1
4 Ring nut 1 Use special tool.
Refer to “REMOVAL POINTS”.
5 Under bracket 1
6 Bearing race cover 1
7 Bearing (upper) 1
8 Bearing (lower) 1 Refer to “REMOVAL POINTS”.
9 Bearing race 2 Refer to “REMOVAL POINTS”. Extent of removal:1Under bracket removal 2Bearing removal
2
1
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Support the machine securely so there is no dan-
ger of it falling over.
EC560000
STEERING
145 Nm (14.5 m•kg, 105 ft•lb)
21 Nm (2.1 m•kg, 15 ft•lb)
9Tighten ring nut.
38 Nm (3.8 m•kg, 27 ft•lb)
9Loosen it one turn.
9Retighten it.
7 Nm (0.7 m•kg, 5.1 ft•lb)
TIGHTENING STEPS:
21 Nm (2.1 m•kg, 15 ft•lb)
4Nm (0.4 m•kg, 2.9 ft•lb)
1C3-9-32-5C 4/14/06 12:05 PM Page 18

5-55
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 Extent of removal:
1Swingarm removal
1
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Support the machine securely so there is no dan-
ger of it falling over.



EC570000
SWINGARM
53 Nm (5.3 m•kg, 38 ft•lb)
80 Nm (8.0 m•kg, 58 ft•lb)
16 Nm (1.6 m•kg, 11 ft•lb)7 Nm (0.7 m•kg, 5.1 ft•lb)
85 Nm (8.5 m•kg, 61 ft•lb)
1C3-9-32-5D 4/7/06 2:51 PM Page 2