Yamaha GL750 prototype

Here we have the Yamaha GL750 prototype, this is a fourcilinder two stroke. It was launched at the Tokyo motorshow in 1972. It had a two-stroke injection system which was also a prototype item for snowmobiles. It never reached production stage. Yamaha destroyed the prototype according to the German intenetsite zweitakte.de. 
For more pics see
Yamaha GL750
For more infomation see
Classic Yams - GL750
And (in German language)
Zweitakte.de - GL750

Stredor boxer sidecar racing engine

Here are some pictures of the Stredor, a work of art made by Egbert STREuer and Rinus DORgelo. This machine was on display at the Speedshow in Cafe Hofsteenge in Grolloo The Netherlands december 2006. It is a two stroke boxer sidecar racing engine with 200 hp. First they used Honda and Yamaha cilinders, at the final version Aprilia.  
For more pics see  
Stredor