Yamaha yz250 2015 User Manual

4-13
CYLINDER HEAD, CYLINDER AND PISTON
CYLINDER HEAD, CYLINDER AND PISTON
REMOVING THE CYLINDER HEAD AND CYLINDER
Order Part name Q'ty Remarks
Seat and fuel tank
Refer to "SEAT, FUEL TANK AND 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 section.
7 Nut (cylinder) 4
8 Cylinder 1
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)
25 Nm (2.5 m kg, 18 ft lb)
13 Nm (1.3 m kg, 9.4 ft lb)
13 Nm (1.3 m kg, 9.4 ft lb)
42 Nm (4.2 m kg, 30 ft lb)
5 Nm (0.5 m kg, 3.6 ft lb)

Yamaha yz250 2015 Specifications

General

Displacement	249cc
Bore x Stroke	66.4mm x 72.0mm
Compression Ratio	8.9~10.6:1
Ignition	CDI
Transmission	5-speed; multiplate wet clutch
Final Drive	Chain
Front Tire	80/100-21
Rear Tire	110/90-19
Wheelbase	58.3 in
Seat Height	39.1 in
Ground Clearance	14.2 in
Fuel Capacity	2.1 gal
Wet Weight	227 lbs
Engine Type	2-stroke
Fuel System	Keihin PWK38S
Front Suspension	KYB Speed-Sensitive System inverted fork; fully adjustable
Rear Suspension	12.4-in travel
Front Brake	Single disc, 250mm
Rear Brake	Hydraulic single disc brake, 245mm
Width	32.5 inches