Motorcycle engines ???

"Vaughn" wrote a fairly
lightweight belt reduction drive, why aren't more rice burners being used
in
UL's?

Many times I have looked down at the faithful engine on my old BMW,
built like the proverbial brick ****house with all roller bearings, and
wondered...

Vaughn

Good question guys. Maybe Chuck S. could tell us. My teenage
infatuation with the extremely lightweight yamaha 125cc two-strokes
lead me to discover that it was because those engine designs were
rated for only momentary high power at the top of the power band. But
that didn't scare the footlaunchers in the 70's!

pacplyer

Google a little bit and you will find several BMW, Honda, and other
motorcycle conversions flying.

You can do it... but usually its easier and more reliable to just bolt in a
Rotax. Jap bike engines usually present the problem of having to deal with the
unitized tranny. And there is always the concern of overheating. There are a
few Harley / S&S / equiv. powered machines out there too. Just depends on the
trade-offs you want to make. USU's carbon-fiber Wright Flyer is using what
looks like a Harley EVO motor.

Harry