The rotary piston (Wankel- engine) RZ201 hit the Tokyo Motorshow in 1973.

The YZ587 factory coded machine did really run and according to reliable sources, there are still 2 or 3 around in the Yamaha workshops.

Yamaha RZ-201 1974 (YZ487)

The few technical data on this remarkable machine I will add later. You can see that there are many similarities with the TX750 in the cycle components.