Yamaha YP250R X-MAX 2005 Service Information page 16

Item
Rocker arms/rocker arm shafts
Rocker arm inside diameter
Rocker arm shaft outside diameter
Rocker-arm-to-rocker-arm-shaft
clearance
Valves, valve seats, valve guides
Valve clearance (cold)
Intake
Exhaust
Valve dimensions
A
Head Diameter
Valve head diameter A
Intake
Exhaust
Valve face width B
Intake
Exhaust
Valve seat width C
Intake
Exhaust
Valve margin thickness D
Intake
Exhaust
Valve stem diameter
Intake
Exhaust
Valve guide inside diameter
Intake
Exhaust
ENGINE SPECIFICATIONS
12.000 ~ 12.0.18 mm (0.4724 ~ 0.4731 in) 12.030 mm
11.981 ~ 11.991 mm (0.4717 ~ 0.4720 in) 11.950 mm
0.009 ~ 0.037 mm (0.0004 ~ 0.0014 in)
0.08 ~ 0.12 mm (0.0031 ~ 0.0047 in)
0.16 ~ 0.20 mm (0.0062 ~ 0.0078 in)
B
Face Width
33.90 ~ 34.10 mm (1.3346 ~ 1.3425 in)
28.40 ~ 28.60 mm (1.1181 ~ 1.1259 in)
3.394 ~ 3.960 mm (0.1336 ~ 0.1559 in)
3.394 ~ 3.960 mm (0.1336 ~ 0.1559 in)
0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
0.90 ~ 1.10 mm (0.0354 ~ 0.0433 in)
0.80 ~ 1.20 mm (0.0314 ~ 0.0472 in)
0.80 ~ 1.20 mm (0.0314 ~ 0.0472 in)
5.975 ~ 5.990 mm (0.2352 ~ 0.2358 in)
5.960 ~ 5.975 mm (0.2346 ~ 0.2352 in)
6.000 ~ 6.012 mm (0.2362 ~ 0.2366 in)
6.000 ~ 6.012 mm (0.2362 ~ 0.2366 in)
2 - 5
Standard
C
Seat Width
SPEC
Limit
(0.4736 in)
(0.4704 in)
0.080 mm
(0.0031 in)
----
----
D
Margin Thickness
----
----
----
----
1.6 mm
(0.06 in)
1.6 mm
(0.06 in)
----
----
5.940 mm
(0.2338 in)
5.920 mm
(0.2082 in)
6.050 mm
(0.2381 in)
6.050 mm
(0.2381 in)