The Yamaha RD56 was a two stroke 250cc Grand Prix racing motorcycle. It had two 56x50mm cylinders, disk valves and an Oldham coupler joining the crank shafts. Power was 47bhp at 11,000rpm. Although the engine was essentially the same as that of the RD48, the frame was a new design based on the Norton Featherbed. It featured a 7 speed gearbox.
|Manufacturer||Yamaha Motor Company|
|Production||1963 - 1964|
- p23 MacKellar.
- p25 MacKellar
MacKellar, Colin (28 Aug 1995). Yamaha: All Factory and Production Road-Racing Two-Strokes from 1955 to 1993. UK: The Crowood Press Ltd. pp. 191. ISBN 1852239204.