Yamaha YFM70RY Service Manual page 32

Valve guide inside diameter (intake)
Limit
Valve guide inside diameter (exhaust)
Limit
Valve-stem-to-valve-guide clearance (intake)
Limit
Valve-stem-to-valve-guide clearance (exhaust)
Limit
Valve stem runout
Cylinder head valve seat width (intake)
Limit
Cylinder head valve seat width (exhaust)
Limit
Valve spring
Free length (intake)
Limit
Free length (exhaust)
Limit
Installed length (intake)
Installed length (exhaust)
Spring rate K1 (intake)
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
Out of round limit
ENGINE SPECIFICATIONS
6.000–6.012 mm (0.2362–0.2367 in)
6.050 mm (0.2382 in)
6.000–6.012 mm (0.2362–0.2367 in)
6.050 mm (0.2382 in)
0.010–0.037 mm (0.0004–0.0015 in)
0.080 mm (0.0031 in)
0.025–0.052 mm (0.0010–0.0020 in)
0.100 mm (0.0039 in)
0.010 mm (0.0004 in)
1.00–1.20 mm (0.0394–0.0472 in)
1.6 mm (0.063 in)
1.00–1.20 mm (0.0394–0.0472 in)
1.6 mm (0.063 in)
38.79 mm (1.53 in)
36.85 mm (1.45 in)
38.79 mm (1.53 in)
36.85 mm (1.45 in)
35.00 mm (1.38 in)
35.00 mm (1.38 in)
48.55 N/mm (4.95 kgf, 277.22 lbf)
63.02 N/mm (6.43 kgf, 359.84 lbf)
48.55 N/mm (4.95 kgf, 277.22 lbf)
63.02 N/mm (6.43 kgf, 359.84 lbf)
169.00–199.00 N (17.23–20.29 kgf, 37.99–
44.73 lbf)
169.00–199.00 N (17.23–20.29 kgf, 37.99–
44.73 lbf)
2.5°/1.70 mm
2.5°/1.70 mm
Clockwise
Clockwise
102.000–102.010 mm (4.0157–4.0161 in)
102.080 mm (4.0189 in)
0.05 mm (0.002 in)
2-5