General Specifications

Cylinder head
Flatness of gasket surface Max. 0.03 mm (0.0012 inch) 0.05 mm
Flatness of mounting
Surface
Intake Max. 0.10 mm (0.0039 inch) 0.10 mm
Exhaust Max. 0.15 mm (0.0059 inch) 0.15 mm
Valve guide hole diameter
0.05 (0.002) O.S. 12.05 - 12.068 mm (0.474 - 0.475 inch)
0.25 (0.010) O.S. 12.25 - 12.268 mm (0.482 - 0.483 inch)
0.50 (0.020) O.S. 12.50 - 12.518 mm (0.492 - 0.493 inch)
Intake valve seat ring hole diameter
0.3 (0.012) O.S. 36.30 - 36.325 mm (1.429 - 1.430 inch)
0.6 (0.024) O.S. 36.60 - 36.625 mm (1.441 - 1.442 inch)
Exhaust valve seat ring hole diameter
0.3 (0.012) O.S. 33.30 - 33.325 mm (1.311 - 1.312 inch)
0.6 (0.024) O.S. 33.60 - 33.625 mm (1.323 - 1.324 inch)
Valve
Overall length
Intake 106.28 mm (4.184 inch) 105.78 mm(4.164 inch)
Exhaust 105.4 mm (4.150 inch) 104.9 mm (4.130 inch)
Stem diameter
Intake 6.565 - 6.580 mm (0.258 - 0.259 inch)
Exhaust 6.530 - 6.550 mm (0.257 - 0.258 inch)
Face angle 45° - 45.5°
Margin
Intake 1.0 mm (0.0394 inch) 0.5 mm (0.0197 inch)
Exhaust 1.5 mm (0.059 inch) 1.0 mm (0.039 inch)
Clearance (stem-to - guide)
Intake 0.02 - 0.05 mm (0.0009 - 0.0020 inch) 0.1 mm (0.0039 inch)
Exhaust 0.05 - 0.085 mm (0.0020 - 0.0033 inch) 0.15 mm (0.0059 inch)
Valve spring
Free height 46.4 mm (1.8268 inch) 45.4 mm (1.787 inch)
Load 24.0 kg /37.9 mm (53 lbs./1.492 inch)
Out of squareness Max 2 4°
Valve guide
Length
Intake 45.5 mm (1.7913 inch)
Exhaust 50.5 mm (1.9882 inch)
Service oversize 0.05, 0.25, 0.50
Valve seat contact width
Intake 0.9 - 1.3 mm (0.035 - 0.051 inch)
Exhaust 0.9 - 1.3 mm (0.035 - 0.051 inch)
Service oversize 0.30, 0.60
Seat angle
Intake 20°
Exhaust 45°