Yamaha 2009 YFM25RY Service Manual page 24

Valve, valve seat, valve guide
Valve clearance (cold)
Intake
Exhaust
Valve dimensions
Valve head diameter A (intake)
Valve head diameter A (exhaust)
Valve face width B (intake)
Valve face width B (exhaust)
Valve seat width C (intake)
Limit
Valve seat width C (exhaust)
Limit
Valve margin thickness D (intake)
Valve margin thickness D (exhaust)
Valve stem diameter (intake)
Limit
Valve stem diameter (exhaust)
Limit
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
(exhaust)
Limit
Valve stem runout limit
Cylinder head valve seat width (intake)
Limit
Cylinder head valve seat width (exhaust)
Limit
ENGINE SPECIFICATIONS
0.05–0.10 mm (0.0020–0.0039 in)
0.10–0.15 mm (0.0039–0.0059 in)
33.90–34.10 mm (1.3346–1.3425 in)
28.40–28.60 mm (1.1181–1.1260 in)
2.26 mm (0.0890 in)
2.26 mm (0.0890 in)
0.90–1.10 mm (0.0354–0.0433 in)
1.60 mm (0.06 in)
0.90–1.10 mm (0.0354–0.0433 in)
1.60 mm (0.06 in)
0.80–1.20 mm (0.0315–0.0472 in)
0.80–1.20 mm (0.0315–0.0472 in)
5.975–5.990 mm (0.2352–0.2358 in)
5.945 mm (0.234 in)
5.960–5.975 mm (0.2346–0.2352 in)
5.930 mm (0.233 in)
6.000–6.012 mm (0.2362–0.2367 in)
6.050 mm (0.238 in)
6.000–6.012 mm (0.2362–0.2367 in)
6.050 mm (0.238 in)
0.010–0.037 mm (0.0004–0.0015 in)
0.080 mm (0.003 in)
clearance
0.025–0.052 mm (0.0010–0.0020 in)
0.100 mm (0.004 in)
0.01 mm (0.0004 in)
0.90–1.10 mm (0.0354–0.0433 in)
1.60 mm (0.06 in)
0.90–1.10 mm (0.0354–0.0433 in)
1.60 mm (0.06 in)
2-5