Engine: Bore Stroke :94.0 mm (3.701 in) x 94.0 mm (3.701 in) , Compression Ratio: 8.5 : 1 , Engine: 652 cc (39.8 cu. in), 4-stroke, air-cooled, OHC , Fuel System :MIKUNI BS40, single , Ignition: Electronic ignition (Transistorized) , Lubrication :Wet sump , Starter: Electric ,