[1] The Scott designer William Cull had been experimenting with three-cylinder two-strokes throughout the 1930s and had developed a prototype 747 cc engine.

The Scott Model 3S which was unveiled at the 1934 Olympia Motorcycle Show[2] was a further development of this work, with the capacity enlarged to 986 cc and a four-speed gearchange.

Another unusual feature was that fuel was held in 'pannier' containers each side of the rear wheel so the apparent fuel tank was actually a dummy housing the instrumentation and control box (a feature later copied by the Honda Gold Wing).

Only eight were produced before the outbreak of World War II.

The final Model 3S is on display at the National Motorcycle Museum (UK).