General Specifications

GENERAL SPECIFICATIONS

Cylinder Head

Combustion chamber volume 52 cc (3.17 CI)
Valve arrangement (front to rear) LH intake IIIIII
Valve arrangement LH exhaust EEEEEE
Valve arrangement RH intake IIIIII
Valve arrangement RH exhaust EEEEEE
Valve guide bore diameter 6.015-6.044 mm (0.236-0.237 inch)
Valve stem diameter intake 5.975-5.995 mm (0.2350-0.2358 inch)
Valve stem diameter exhaust 5.950-5.970 mm (0.2343-0.2350 inch)
Valve stem-to-guide clearance - intake 0.019-0.069 mm (0.0007-0.0027 inch)
Valve stem-to-guide clearance - exhaust 0.046-0.095 mm (0.0018-0.0037 inch)
Valve head diameter intake 35 mm (1.38 inch)
Valve head diameter exhaust 30 mm (1.18 inch)
Valve head diameter (intake) gauge diameter 33.5 mm (1.3189 inch)
Valve head diameter (exhaust) gauge diameter 28.0 mm (1.10236 inch)
Valve face runout 0.04 mm (0.001 inch)
Valve face angle 45.2545.75 degrees
Valve seat width intake 1.11.4 mm (0.0430.055 inch)
Valve seat width exhaust 1.41.7 mm (0.055-0.066 inch)
Valve seat runout 0.04 mm (0.001 inch)
Valve seat angle 44.5-45.0 degrees
Valve spring free length (approx.) 46.6 mm (1.84 inch)
Valve spring squareness 2.5%
Valve spring compression Pressure (N @ spec. length) 693 N @ 30.09 mm (156 pressure 156 lbs. @ 1.18 inch)
Valve spring installed height (N @ spec. length) 39.89 mm ± 0.2 mm (1.57 inch ± 0.0078 inch)
Valve spring installed pressure 240 N ± 12 N @ 39.89 mm (53.95 lbs. ± 2.69 lbs. ± 1.57 inch)
Valve spring installed pressure - service limit 10% force loss @ specified height
Roller follower ratio @ max. lift 2.0:1
Hydraulic Lash Adjuster
Diameter (standard) 16-15.988 mm (0.6290-0.6294 inch) Clearance-to-bore 0.018-0.069 mm (0.0007-0.0027 inch)
Hydraulic leakdown rate 525 seconds
Collapsed lash adjuster gap 0.50-1.11 mm (0.019-0.043 inch)