In about 1902 J.A.Prestwich and Company started the manufacture of motorcycle engines which were used in many famous motorcycle marques. The motorcycle engines were associated with racing and record success and were still used in speedway bikes well into the 1960s. From 1904 to 1908 complete motorcycles were produced from the development of the first overhead valve motorcycle engine to be produced in the UK. After that the factory concentrated on supplying its engines to other manufacturers, including Brough Superior, Triumph Motorcycles, and HRD Motorcycles, the forerunner of Vincent Motorcycles.Machines that incorporated its engines included the AJS Model D, fabricated for the Russians in the First World War. JAP exported significant numbers of engines to foreign motorcycle manufacturers including Dresch and Terrot in France, and Ardie, Hecker and Tornax in Germany. JAP engines (under Villiers control) were used in motorcycle racing, and most commonly speedway or dirt track.