Yamaha YFM70RY Service Manual page 31

Timing chain
Model/number of links
Tensioning system
Rocker arm/rocker arm shaft
Rocker arm inside diameter
Rocker arm shaft outside diameter
Rocker-arm-to-rocker-arm-shaft clearance
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
A
B
C
D
ENGINE SPECIFICATIONS
98XRH2010/126
Automatic
12.000–12.018 mm (0.4724–0.4731 in)
11.981–11.991 mm (0.4717–0.4721 in)
0.009–0.037 mm (0.0004–0.0015 in)
0.09–0.13 mm (0.0035–0.0051 in)
0.16–0.20 mm (0.0063–0.0079 in)
37.90–38.10 mm (1.4921–1.5000 in)
31.90–32.10 mm (1.2559–1.2638 in)
2.26 mm (0.0890 in)
2.26 mm (0.0890 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)
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 (0.2341 in)
5.960–5.975 mm (0.2346–0.2352 in)
5.930 mm (0.2335 in)
2-4