2007 YAMAHA YZ125LC fuel

4-7
ENGCARBURETOR AND REED VALVE
EC460000
CARBURETOR AND REED VALVE
Extent of removal Order Part name Q’ty Remarks
CARBURETOR AND
REED VALVE REMOVAL
Preparation for Fuel tank Refer to “SEAT, FUEL TANK AND
removal SIDE COVERS” section.
1 Clamp (carburetor joint) 2
Loosen the screws (carburetor joint).
2 Carburetor 1
3 Carburetor joint 1
4 Reed valve assembly 1
5 Stopper (reed valve) 2
6 Reed valve 21
Extent of removal:1Carburetor removal2Reed valve removal
2
10 Nm (1.0 m•kg, 7.2 ft•lb)
1 Nm (0.1 m•kg, 0.7 ft•lb)
2 Nm (0.2 m•kg, 1.4 ft•lb)
2 Nm (0.2 m•kg, 1.4 ft•lb)
1C3-9-32-4A 4/6/06 2:07 PM Page 14

4-11
ENGCARBURETOR AND REED VALVE
Measurement and adjustment steps:
9Remove the drain plug.
9Connect the fuel level gauge adapter 2and
fuel level gauge 1to the float chamber.
Fuel level gauge adapter:
YM-01470/90890-01470
Fuel level gauge:
YM-1312-A/90890-01312
9Hold the fuel level gauge vertically next to
the float chamber mating surface.
9Measure the fuel level with the fuel level
gauge.
NOTE:
Keep the carburetor and fuel level gauge ver-
tically when measuring the fuel level.
9If the fuel level is not within specification, in-
spect the valve seat and needle valve.
9If either is worn, replace them both.
9If both are fine, adjust the fuel level by bend-
ing the float tab bon the float.
9Recheck the fuel level.
EC464802
Fuel level
1. Measure:
9Fuel level a
Out of specification Adjust.
Fuel level:
9.5~10.5 mm (0.37~0.41 in)
Above the float chamber
mating surface
EC464A00
Filter
1. Inspect:
9Filter 1
Damage  Replace.
NOTE:
Inspect the filter as it is assembled to the carbu-
retor. Do not remove the filter except when
replacing it.
1C3-9-32-4A 4/6/06 2:07 PM Page 22

4-17
ENGCYLINDER HEAD, CYLINDER AND PISTON
EC470000
CYLINDER HEAD, CYLINDER AND PISTONEC478000
CYLINDER HEAD AND CYLINDER
Extent of removal Order Part name Q’ty Remarks
CYLINDER HEAD AND
CYLINDER REMOVAL
Preparation for Seat and fuel tank Refer to “SEAT, FUEL TANK AND
removal SIDE COVERS” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
SILENCER” section.
Radiator Refer to “RADIATOR” section.
1 Spark plug 1
2 Engine bracket 2
3 Nut (cylinder head) 5
Loosen each nut 1/4 turn, and remove
them after all nuts are loosened.
4 Cylinder head 1
5 Power valve housing 1
6 Push rod 1 Refer to “REMOVAL POINTS”.
7 Nut (cylinder) 4
8 Cylinder 1
Extent of removal:1Cylinder head removal2Cylinder removal
1
2
34 Nm (3.4 m•kg, 24 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
28 Nm (2.8 m•kg, 20 ft•lb)
4 Nm (0.4 m•kg, 2.9 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
30 Nm (3.0 m•kg, 22 ft•lb)
13 Nm (1.3 m•kg, 9.4 ft•lb)
1C3-9-32-4A 4/6/06 2:07 PM Page 34

4-52
ENGCDI MAGNETO
Extent of removal Order Part name Q’ty Remarks
CDI MAGNETO REMOVAL
Preparation for Seat and fuel tank Refer to “SEAT, FUEL TANK AND
removal SIDE COVERS” section.
Bolt (Radiator) Refer to “RADIATOR” section.
Disconnect the CDI magneto lead.
1 Crankcase cover (left) 1
2 Nut (rotor) 1 Use special tool.
3 Rotor 1 Refer to “REMOVAL POINTS”.
4 Stator 1
5 Woodruff key 1
EC4L0000
CDI MAGNETO
1
Extent of removal:1CDI magneto removal



7 Nm (0.7 m•kg, 5.1 ft•lb)
56 Nm (5.6 m•kg, 40 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
1C3-9-32-4C 4/6/06 2:13 PM Page 32

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

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
w
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
w
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

5-63
CHASREAR SHOCK ABSORBER
Extent of removal:1Rear shock absorber removal 2Rear shock absorber disassembly
56 Nm (5.6 m•kg, 40 ft•lb)
53 Nm (5.3 m•kg, 38 ft•lb)
32 Nm (3.2 m•kg, 23 ft•lb)
EC580000
REAR SHOCK ABSORBER
29 Nm (2.9 m•kg, 21 ft•lb)
2 Nm (0.2 m•kg, 1.4 ft•lb)
Extent of removal Order Part name Q’ty Remarks
REAR SHOCK ABSORBER
REMOVAL
Preparation forHold the machine by placing the
removalsuitable stand under the engine.
SeatRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section in the CHAPTER 4.
SilencerRefer to “EXHAUST PIPE AND
SILENCER” section in the CHAPTER 4.
1 Clamp (air cleaner joint) 1 Loosen the bolt (air cleaner joint).
2 Rear frame 1
3
Bolt (rear shock absorber-relay arm)1 Hold the swingarm.
4 Bolt (rear shock absorber-frame) 1
5 Rear shock absorber 1
6 Locknut 1
7 Adjuster 1
8 Spring seat 2
9 Spring guide (lower) 1
10 Spring guide (upper) 1
11 Spring (rear shock absorber) 1
12 Bearing 2 Refer to “REMOVAL POINTS”.
2
w
Support the machine securely so there is no dan-
ger of it falling over.
1
1C3-9-32-5D 4/7/06 2:51 PM Page 18