Yamaha WR250R Service Manual page 30

Spring rate K2 (intake)
Spring rate K1 (exhaust)
Spring rate K2 (exhaust)
Installed compression spring force (intake)
Installed compression spring force (exhaust)
Spring tilt (intake)
Spring tilt (exhaust)
Winding direction (intake)
Winding direction (exhaust)
Cylinder
Bore
Wear limit
Taper limit
Out of round limit
Piston
Piston-to-cylinder clearance
Limit
Diameter D
Height H
D
Offset
Offset direction
Piston pin bore inside diameter
Limit
Piston pin outside diameter
Limit
Piston-pin-to-piston- pin-bore clearance
40.90 N/mm (233.54 lb/in) (4.17 kgf/mm)
31.47 N/mm (179.69 lb/in) (3.21 kgf/mm)
40.90 N/mm (233.54 lb/in) (4.17 kgf/mm)
147.00–169.00 N (33.05–37.99 lbf)
(14.99–17.23 kgf)
147.00–169.00 N (33.05–37.99 lbf)
(14.99–17.23 kgf)
2.5 °/1.6 mm
2.5 °/1.6 mm
Clockwise
Clockwise
77.000–77.010 mm (3.0315–3.0319 in)
77.100 mm (3.0354 in)
0.050 mm (0.0020 in)
0.050 mm (0.0020 in)
0.010–0.035 mm (0.0004–0.0014 in)
0.10 mm (0.0039 in)
76.975–76.990 mm (3.0305–3.0311 in)
12.0 mm (0.47 in)
H
0.50 mm (0.0197 in)
Intake side
17.002–17.013 mm (0.6694–0.6698 in)
17.043 mm (0.6710 in)
16.991–17.000 mm (0.6689–0.6693 in)
16.971 mm (0.6681 in)
0.002–0.022 mm (0.0001–0.0009 in)
2-5
ENGINE SPECIFICATIONS