Yamaha YZ250F(E) Owner's Service Manual page 46

Cylinder head
Volume
Warpage limit
Camshaft
Drive system
Camshaft cap inside diameter
Camshaft journal diameter
Camshaft-journal-to-camshaft-cap clearance
Camshaft lobe dimensions
Intake A
Limit
Intake B
Limit
Exhaust A
Limit
Exhaust B
Limit
Camshaft runout limit
Timing chain
Tensioning system
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)
A
B
A
B
ENGINE SPECIFICATIONS
12.07–12.87 cm
0.05 mm (0.0020 in)
Chain drive (left)
22.000–22.021 mm (0.8661–0.8670 in)
21.959–21.972 mm (0.8645–0.8650 in)
0.028–0.062 mm (0.0011–0.0024 in)
31.730–31.830 mm (1.2492–1.2531 in)
31.630 mm (1.2453 in)
22.450–22.550 mm (0.8839–0.8878 in)
22.350 mm (0.8799 in)
33.370–33.470 mm (1.3138–1.3177 in)
33.270 mm (1.3098 in)
25.211–25.311 mm (0.9926–0.9965 in)
25.111 mm (0.9886 in)
0.030 mm (0.0012 in)
Automatic
0.12–0.19 mm (0.0047–0.0075 in)
0.17–0.24 mm (0.0067–0.0094 in)
30.90–31.10 mm (1.2165–1.2244 in)
24.90–25.10 mm (0.9803–0.9882 in)
1.697 mm (0.0668 in)
1.909 mm (0.0752 in)
2-3
3
(0.74–0.79 cu.in)