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 47 bhp at 11,000rpm.[1] 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.

Yamaha RD56
ManufacturerYamaha Motor Company
Production1963–1964
PredecessorYamaha RD48
SuccessorYamaha RD05
Engine250cc two-stroke

It was ridden by Yoshikazu Sunako, Fumio Ito, Hiroshi Hasegawa and Tony Godfrey for the 1963 Grand Prix season.

The engine was improved for the 1964 season generating a claimed 50 bhp at 11,000 rpm.[2] Phil Read joined the Yamaha team and narrowly beat Redman to become Grand Prix World Champion.

Hiroshi Hasegawa won the 1967 Macau Grand Prix.

References

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  1. ^ p23 MacKellar.
  2. ^ p25 MacKellar

Bibliography

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MacKellar, Colin (28 August 1995). Yamaha: All Factory and Production Road-Racing Two-Strokes from 1955 to 1993. UK: The Crowood Press Ltd. p. 191. ISBN 1-85223-920-4.