Yamaha 2004 YP400, Service Manual, Page: 35 / 417

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SPEC
ENGINE SPECIFICATIONS
Timing chain
Model/number of links SCR-0409 SDH/136 ----
Tensioning system Automatic ----
Valves, valve seats, valve guides
Valve clearance (cold)
Intake 0.15 ~ 0.20 mm (0.0059 ~ 0.0079 in) ----
Exhaust 0.25 ~ 0.30 mm (0.0098 ~ 0.0118 in) ----
Valve dimensions
Valve head diameter A
Intake 30.9 ~ 31.1 mm (1.2165 ~ 1.2244 in) ----
Exhaust 27.9 ~ 28.1 mm (1.0984 ~ 1.1063 in) ----
Valve face width B
Intake 1.838 ~ 2.687 mm (0.0724 ~ 0.1058 in) ----
Exhaust 1.697 ~ 2.828 mm (0.0668 ~ 0.1113 in) ----
Valve seat width C
Intake 1.0 ~ 1.2 mm (0.0394 ~ 0.0472 in) 1.6 mm
(0.06 in)
Exhaust 1.0 ~ 1.2 mm (0.0394 ~ 0.0472 in) 1.6 mm
(0.06 in)
Valve margin thickness D
Intake 0.85 ~ 1.15 mm (0.0335 ~ 0.0453 in) ----
Exhaust 0.85 ~ 1.15 mm (0.0335 ~ 0.0453 in) ----
Valve stem diameter
Intake 4.975 ~ 4.990 mm (0.1959 ~ 0.1965 in) 4.945 mm
(0.1947 in)
Exhaust 4.960 ~ 4.975 mm (0.1953 ~ 0.1959 in) 4.930 mm
(0.1941 in)
Valve guide inside diameter
Intake 5.000 ~ 5.015 mm (0.1969 ~ 0.1974 in) 5.053 mm
(0.1989 in)
Exhaust 5.000 ~ 5.015 mm (0.1969 ~ 0.1974 in) 5.053 mm
(0.1989 in)
Valve-stem-to-valve-guide clearance
Intake 0.010 ~ 0.037 mm (0.0004 ~ 0.0015 in) 0.080 mm
(0.0032 in)
Exhaust 0.025 ~ 0.052 mm (0.0010 ~ 0.0020 in) 0.100 mm
(0.0039 in)
Item Standard Limit
B
C
D
A
Head Diameter Face Width Seat Width Margin Thickness