* Combustion chamber volume: 58.1 cc
* Intake valve diameter: 35.5 mm
* Exhaust valve diameter: 32.0 mm
* Intake valve seat width: 2.0 mm
* Exhaust valve seat width: 2.0 mm
* Intake valve stem diameter: 8.0 mm
* Exhaust valve stem diameter: 7.9 mm
* Intake valve spring installed height: 40.7 mm
* Exhaust valve spring installed height: 40.4 mm
* Intake valve spring pressure (closed): 30 N/mm
* Exhaust valve spring pressure (closed): 30 N/mm
* Intake valve spring pressure (open): 84 N/mm
* Exhaust valve spring pressure (open): 84 N/mm
* Piston to cylinder head clearance: 0.80 mm
* Cylinder head thickness: 96.0 mm
* Cylinder head bolt torque: 60 Nm (44 lb-ft)
