fuel tank removal YAMAHA YZ250LC 2007 Manuale duso (in Italian)

CHAPTER 4
ENGINE
SEAT, FUEL TANK AND SIDE
COVERS.....................................................4-1
EXHAUST PIPE AND SILENCER..............4-3
RADIATOR..................................................4-4
CARBURETOR AND REED VALVE...........4-7
CYLINDER HEAD , CYLINDER AND
PISTON.....................................................4-18
CLUTCH AND PRIMARY DRIVEN
GEAR.......................................................4-33
KICK AXLE, SHIFT SHAFT AND
PRIMARY DRIVE GEAR...........................4-40
YPVS GOVERNOR...................................4-49
WATER PUMP..........................................4-52
CDI MAGNETO.........................................4-56
ENGINE REMOVAL..................................4-60
CRANKCASE AND CRANKSHAFT.........4-65
TRANSMISSION, SHIFT CAM AND
SHIFT FORK.............................................4-72
CHAPTER 5
CHASSIS
FRONT WHEEL AND REAR WHEEL........5-1
FRONT BRAKE AND REAR BRAKE.......5-10
FRONT FORK...........................................5-26
HANDLEBAR............................................5-42
STEERING................................................5-50
SWINGARM..............................................5-55
REAR SHOCK ABSORBER.....................5-63
1P8-9-32-0 4/28/06 9:44 AM Page 20

4-1
SEAT, FUEL TANK AND SIDE COVERSENG
EC400000
ENGINE
EC4R0000
SEAT, FUEL TANK AND SIDE COVERS
Extent of removal Order Part name Q’ty Remarks
SEAT, FUEL TANK AND SIDE
COVERS REMOVAL
Preparation for Turn the fuel cock to “OFF”.
removal Disconnect the fuel hose.
1 Seat 1
2 Air scoop (left and right) 2
3 Fitting band 1 Remove on fuel tank side.
4 Bolt (fuel tank) 2
5 Fuel tank 1
6 Side cover (left) 1
7 Side cover (right) 1 Refer to “REMOVAL POINTS”.
8 Number plate 1
1
4
Extent of removal:1Seat removal2Fuel tank removal
3Side covers removal4Number plate removal
2
3
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
4 Nm (0.4 m•kg, 2.9 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
7 Nm (0.7 m•kg, 5.1 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
19 Nm (1.9 m•kg, 13 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)





7 Nm (0.7 m•kg, 5.1 ft•lb)
1P8-9-32-4a 4/10/06 1:52 PM Page 2

4-2
ENGSEAT, FUEL TANK AND SIDE COVERS
EC4R3000
REMOVAL POINTS
EC413110
Side cover
1. Remove:
9Bolt (side cover)
9Side cover (left and right) 1
NOTE:
Draw the side cover downward to remove it
because its claws aare inserted in the air
cleaner case.
Number plate
1. Remove:
9Bolt (number plate)
9Number plate 1
NOTE:
9The projection ais inserted into the band of
the number plate. Pull the band off the projec-
tion before removal.
9Remove the clutch cable 2from the cable
guide bon the number plate.
9The projection con the under bracket is
inserted into the number plate. Remove the
number plate by pulling it off the projection.
1P8-9-32-4a 4/10/06 1:52 PM Page 4

åExcept for USA and CDN
Extent of removal:1Silencer removal2Exhaust pipe removal
Extent of removal Order Part name Q’ty Remarks
EXHAUST PIPE AND
SILENCER REMOVAL
Preparation for Side cover (right) Refer to “SEAT, FUEL TANK AND
removal SIDE COVERS” section.
1 Bolt (silencer) 2
2
Plain washer [ø=22 mm (0.87 in)] 1
Plain washer [ø=26 mm (1.02 in)] 1
3 Silencer 1
4 Collar [R=ø13.0 mm (0.51 in)] 1
Collar [R=ø15.5 mm (0.61 in)] 1
5 Collar [R=ø13.5 mm (0.53 in)] 1
6 Grommet (front) 1
7 Grommet (rear) 1
8 Tension spring 2
9 Bolt (exhaust pipe) 2
10 Exhaust pipe 1
4-3
EXHAUST PIPE AND SILENCERENG
EC4S0000
EXHAUST PIPE AND SILENCER
12 Nm (1.2 m•kg, 8.7 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)
12 Nm (1.2 m•kg, 8.7 ft•lb)
14 Nm (1.4 m•kg, 10 ft•lb)
1
2
2
*4 *2
*Except for USA and CDN
å
1P8-9-32-4a 4/10/06 1:52 PM Page 6

4-4
RADIATORENG
Extent of removal Order Part name Q’ty Remarks
RADIATOR REMOVAL
Preparation for Drain the coolant.
Refer to “COOLANT REPLACEMENT”
removal section in the CHAPTER 3.
Seat and fuel tank Refer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
1 Panel 2
2 Clamp (radiator hose 2) 2 Only loosening.
3 Radiator hose 1 1
4 Radiator (left) 1
5 Radiator hose 4 1
6 Radiator (right) 1
7 Radiator hose 2 2
8 Radiator breather hose 1
EC450001
RADIATOR
Extent of removal:1Radiator removal
1
2 Nm (0.2 m•kg, 1.4 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
2 Nm (0.2 m•kg, 1.4 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
10 Nm (1.0 m•kg, 7.2 ft•lb)
1P8-9-32-4a 4/10/06 1:52 PM Page 8

4-7
CARBURETOR AND REED VALVEENG
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 Solenoid valve lead 1 Disconnect the solenoid valve lead.
2 TPS (throttle position sensor) 1 Disconnect the TPS
lead (throttle position sensor) lead.
3 Clamp (carburetor joint) 2
Loosen the screws (carburetor joint).
4 Carburetor 1
5 Carburetor joint 1
6 Reed valve assembly 1
7 Stopper (reed valve) 2
8 Reed valve 2
9 Plate (reed valve) 1
1
Extent of removal:1Carburetor removal2Reed valve removal
10 Nm (1.0 m•kg, 7.2 ft•lb)
1 Nm (0.1 m•kg, 0.7 ft•lb)
2
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4-18
CYLINDER HEAD, CYLINDER AND PISTONENG
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 hose 1 Disconnect at cylinder head side.
Carburetor Refer to “CARBURETOR AND REED
VALVE” section.
1 Spark plug 1
2 Engine bracket 2
3 Nut (cylinder head) 6
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)
64 Nm (6.4 m•kg, 46 ft•lb)
20 Nm (2.0 m•kg, 14 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
5 Nm (0.5 m•kg, 3.6 ft•lb)
25 Nm (2.5 m•kg, 18 ft•lb)
13 Nm (1.3 m•kg, 9.4 ft•lb)
42 Nm (4.2 m•kg, 30 ft•lb)
13 Nm (1.3 m•kg, 9.4 ft•lb)
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4-56
CDI MAGNETOENG
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)
5 Nm (0.5 m•kg, 3.6 ft•lb)
56 Nm (5.6 m•kg, 40 ft•lb)
1P8-9-32-4c 5/1/06 10:46 AM Page 14

Extent of removal Order Part name Q’ty Remarks
ENGINE REMOVAL
Preparation for
Hold the machine by placing the
removalsuitable stand under the engine.
Drain the transmission oil. Refer to “TRANSMISSION OIL
REPLACEMENT” section in the
CHAPTER 3.
Seat and fuel tankRefer to “SEAT, FUEL TANK AND
SIDE COVERS” section.
CarburetorRefer to “CARBURETOR AND REED
VALVE” section.
Exhaust pipe and silencer Refer to “EXHAUST PIPE AND
Exhaust pipe stay (rear) SILENCER” section.
Clutch cable Disconnect at engine side.
Radiator Refer to “RADIATOR” section.
Spark plug
Disconnect the CDI magneto lead.
4-60
ENGINE REMOVALENG
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)
64 Nm (6.4 m•kg, 46 ft•lb)
75 Nm (7.5 m•kg, 54 ft•lb)
5 Nm (0.5 m•kg, 3.6 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)
åExcept for USA and CDN
4 Nm (0.4 m•kg, 2.9 ft•lb)
1P8-9-32-4c 5/1/06 10:46 AM 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
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
1P8-9-32-5b 4/5/06 4:23 PM Page 2