Yamaha YZ250(W)/W1, Owner'S Service Manual

Page: 254 / 596

4-18
CYLINDER HEAD, CYLINDER AND PISTON
ENG
EC470000
CYLINDER HEAD, CYLINDER AND PISTON
EC478000
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:
1
Cylinder head removal
2
Cylinder 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)
1P8-9-32-4a 4/10/06 1:53 PM Page 36