Yamaha XMAX 125, Service Manual

Page: 81 / 498

ENGINE SPECIFICATIONS (YP250R)
2-50
Timing chain
Tensioning system Automatic
Rocker arm/rocker arm shaft
Rocker arm inside diameter 12.000–12.018 mm (0.4724–0.4731 in)
Limit 12.030 mm (0.4736 in)
Rocker arm shaft outside diameter 11.981–11.991 mm (0.4717–0.4721 in)
Limit 11.950 mm (0.4705 in)
Rocker-arm-to-rocker-arm-shaft clearance 0.009–0.037 mm (0.0004–0.0015 in)
Limit 0.080 mm (0.0031 in)
Valve, valve seat, valve guide
Valve clearance (cold)
Intake 0.08–0.12 mm (0.0031–0.0047 in)
Exhaust 0.16–0.20 mm (0.0063–0.0079 in)
Valve dimensions
Valve head diameter A (intake) 33.90–34.10 mm (1.3346–1.3425 in)
Valve head diameter A (exhaust) 28.40–28.60 mm (1.1181–1.1260 in)
Valve face width B (intake) 3.394–3.960 mm (0.1336–0.1559 in)
Valve face width B (exhaust) 3.394–3.960 mm (0.1336–0.1559 in)
Valve seat width C (intake) 0.90–1.10 mm (0.0354–0.0433 in)
Limit 1.6 mm (0.06 in)
Valve seat width C (exhaust) 0.90–1.10 mm (0.0354–0.0433 in)
Limit 1.6 mm (0.06 in)
Valve margin thickness D (intake) 0.80–1.20 mm (0.0315–0.0472 in)
Limit 0.5 mm (0.02 in)
Valve margin thickness D (exhaust) 0.80–1.20 mm (0.0315–0.0472 in)
Limit 0.5 mm (0.02 in)
Valve stem diameter (intake) 5.975–5.990 mm (0.2352–0.2358 in)
Limit 5.940 mm (0.2339 in)
Valve stem diameter (exhaust) 5.960–5.975 mm (0.2346–0.2352 in)
Limit 5.920 mm (0.2331 in)
A
B
C
D