Yamaha XS650SE, Shop Manual

Page: 204 / 215

1.
Engine type Air cooled, SOHC twin,
parallel forward incline
Engine model
Displacement 653 cc (39.85
Bore stroke 75 74 mm (2.953 2.913 in)
51 Compression ratio 8.5
61 Starting system. Kick and electric starter
7) Ignition system Battery ignition
Lubrication system wet sump
2. CYLINDER HEAD
1 Combustion chamber volume (with 43.6 cc
Combustion chamber type Dome Squish
Head gasket thickness 1.2 mm in)
3. CYLINDER
1 Material Aluminum alloy with cast iron sleeve
Bore size
Taper limit
i n )
Out of round limit 0.01 mm (0.0004 in)
PISTON
Piston skirt clearance 0.050 0.055 mm ~0.0020 0.0022 in)
21 Piston oversize 7 5 . 2 5 75.50 mm 75.75 m m
i n ,
Piston pin outside diameter length
20.0 mm 61 .o
IO.79 in 2.40
16
5. PISTON RING
Piston ring design
ring
1.2 mm 1.5 2.8 mm
21 Ring end gap top) 0.2 0.4 mm (0.008 0.016 in)
2nd) 0.2 0.4 mm 0.016 in)
(Installed. oil) 0.3 0.9 mm 0.035
Ring groove side clearance (Top) 0.04 0.08 mm (0.0016 0.0031
0.03 0.07 mm (0.0012 0.0028 in)
6. END BEARING
Needle bearing
2) Bearing size
31 Needle size
7. CAMSHAFT
1 Cam drive type Chain (Center side)
21 Number and type of bearing 4 bearings, Ball bearings
Bearing type
41 Cam dimensions