J.A. Prestwich Industries, a British manufacturer. JAP began manufacturing engines around 1902. While they produced complete motorcycles for a brief period (1903–1908), their primary business was supplying engines to other manufacturers. These engines powered numerous well-known marques, including Brough Superior, Triumph, Royal Enfield, and Morgan three-wheelers. JAP engines were renowned for their quality and performance, particularly in racing and speedway. However, the company also produced engines for everyday transportation and other uses. This engine is functional, although would suggest a service given age.