Monster Motor | A Look Inside Harley's 120R Engine Photo Gallery
A Look Inside Harleys 120R Engine Compustion Chamber
28 Special attention was also applied to the combustion chamber of the 120R head. The 95cc combustion chamber has more of a kidney-bean shape as compared to the oval/bathtub shape of the OE combustion chamber. The head also features larger valves with a 2.120-inch intake and a 1.635-inch exhaust valve. They are outfitted with automatic compression releases and SE high-lift race springs.