Really dumb but you have to admire the engineering...

[robert]

Interesting, then the power to weight ratio may be quite high.

 

[tankdriver]

We used to put them on gocarts. 1 for each drive wheel.....

You could really get some speed out of them..... :laughing:

 

[Mower manic]

Believe it or not the rotary engine saw by Dolmar has been available since 1975 and they are quite valuable. Heavier than you would think, about 17 lbs.
The motorcycle would have been alot more impressive if it was driven in the video.
It's called a belt.....