William S. Harley and Arthur Davidson developed the first prototype of a Harley Davidson motorcycle in 1903. The engine was designed according to the system De Dion-Bouton, had a displacement of 167 cc and made about 2 ps (1.5 kW). Since Harley and Davidson were dissatisfied with the performance, in 1904, cubic capacity was increased to 405 cm3 at one of bore 76 mm and one stroke 89 mm. From this pre-production model came two copies.[2]
