In September 1972, Outboard Marine Corp. put into production the first rotary combustion (RC) engine manufactured in the western hemisphere. All design, development, manufacturing, and assembly is done within the corporation. The paper discusses many of the design concepts and design considerations for the snowmobile application. Cooling, one of the most difficult obstacles for air-cooled, charge-cooled engines, is covered in some detail. Engine performance, lubrication, noise control, and the capacitive discharge ignition system are also described. Finally, internal inspection methods unique to the RC engine are explained.