Wayne : There were lot's of experimental efforts back in those days using the powerful snow mobile engines in lots of different types of vehicles. We were of course into off road trike racing. and on of my friends was given a Yamaha 440 CC engine equipped with an experimental fuel injection set up and huge expansion chambers and a tune able clutch.
When that engine was put into a Tri-Sport RTS frame that thing would fly once it got up on the pipe. But racing on our short modified mini bike tracks he could never get it to perform well enough to beat smaller less equipped machines.
We even had a 650 CC free air Kohler engine that was way to much for short track racing I made a Trike so light weight it didn't even have seat padding and used a Horstman oil bath kart clutch and a McCulloch 101A twin carbed engine and we raced speedway style at a very famous Firestone Raceway a little 10th of a mile Bull Ring. And my friend Wayne Coppers @ 155 Pounds Shure whooped a lot of Butt in that little trike.
We had so much fun in those days.
Steve