Primary housing assembly for a motorcycle engine

摘要

A primary housing for a motorcycle engine includes an inner housing that defines internal coupling apertures, transmission coupling apertures, and external coupling apertures. Internal fasteners extend through the internal coupling apertures and the transmission coupling apertures to couple the inner housing to the crankcase and the transmission. An outer housing defines coupling apertures that align with the external coupling apertures and fasteners extend through the coupling apertures, through the external coupling apertures, and into the engine crankcase to couple the inner and outer housings to the crankcase. A resonant damping device is rigidly or moveably coupled to an anti-node region of the outer housing to reduce noise emissions from the outer housing during engine operation.