The 350 Sidevalves

1912-1914: 349cc, 75 x 79, 2 3/4 HP

John Marston Ltd had started making bicycles in 1887, and had carried out experiments in 1903/04 with power-assisted bicycles, using Motosacoche engines. It was not until Harry Stevens (of AJS fame) was contracted to design an engine for JML that development started in earnest. John Greenwood was recruited from Rover to design a complete motorcycle, and the result was the 75 x 79mm 2¾ HP machine illustrated below. Greenwood made a few changes to Stevens’ engine, most noticeably moving the magneto from in front of the cylinder to behind it. The machine also featured a two-speed countershaft gearbox and all-chain drive, fully protected by chaincases

1923 Model 1

1926 Model 1