Engine: Bore Stroke: 81.0 mm (3.189 in) x 62.6 mm (2.465 in , Compression Ratio :11.5 :1 , Engine :645 cc (39.4 cu. in), 4-stroke, liquid-cooled, DOHC, 90-degree V-twin , Fuel System: Fuel injection, Ignition: Electronic ignition (Transistorized), Lubrication: Wet sump , Starter: Electric ,