General Specifications

Cylinder Head and Valve Train
Combustion chamber volume 48.1-51.1 cc (2.92-3.12 cu inch)
Valve arrangement (front to rear) - LH I-E-I-I-E-I-I-E-I-I-E-I-I-E-I
Valve arrangement (front to rear) - RH I-E-I-I-E-I-I-E-I-I-E-I-I-E-I
Valve guide bore diameter 6.015-6.044 mm (0.237-0.238 inch)
Valve stem diameter - intake 5.975-5.995 mm (0.235-0.236 inch)
Valve stem diameter - exhaust 5.95-5.97 mm (0.234-0.235 inch)
Valve stem-to-guide clearance - intake 0.020-0.069 mm (0.001-0.003 inch)
Valve stem-to-guide clearance - exhaust 0.045-0.094 mm (0.002-0.004 inch)
Valve head diameter - intake 33.62-33.98 mm (1.324-1.338 inch)
Valve head diameter - exhaust 37.32-37.68 mm (1.469-1.483 inch)
Valve face runout 0.05 mm (0.002 inch)
Valve face angle 45.5 degrees
Valve seat width - intake 1.2-1.4 mm (0.047-0.055 inch)
Valve seat width - exhaust 1.4-1.6 mm (0.055-0.063 inch)
Valve seat angle 44.5-45.0 degrees
Valve spring free length 56.5 mm (2.22 inch)
Valve spring compression pressure 760 N (79 lbs.) ± 17.5 N (171 lbs.) @ 42.04 mm (1.66 inch)
Valve spring installed height 42.04 mm (1.66 inch)
Valve spring installed pressure 350 N (79 lbs.) ± 17.5 N (4 lbs.) @ 42.04 mm (1.66 inch)
Camshaft
Theoretical valve lift @ lash - intake 0 11.1 mm (0.437 inch)
Theoretical valve lift @ lash - exhaust 0 11.0 mm (0.433 inch)
Lobe lift - intake 5.475 mm (0.216 inch)
Lobe lift - exhaust 5.520 mm (0.217 inch)
Allowable lobe lift loss 0.127 mm (0.005 inch)
Journal diameter 28.607-28.633 mm (1.126-1.127 inch)
Camshaft journal bore inside diameter 28.657-28.682 mm (1.128-1.129 inch)
Camshaft journal-to-bearing clearance 0.024-0.075 mm (0.0009-0.0029 inch)
Runout 0.09 mm (0.004 inch)
End play 0.035-0.050 mm (0.0013-0.0019 inch)