Baron, we run our sidecar and have run our 125 at the BUB event.......it sounds like you have the same engine that we have been running.....it has been the basis for the Aprillia GP motor.....if possible try to get a hold of the special cylinder that Aprillia used......the engine is no longer made by Rotax but parts are still on the market from the Rotax importer in CA. (Tony Murphy) When I was at the Rotax factory a few years back, I saw 55hp on the pump with the special cylinder and pipe......the pipe... made out of mag
can still be gotten from Nico Bakker at Bakker Framebouw in the Netherlands.
Best of luck with your bike, and we will see you at the 2011 BUB....(look for the Bakker Motorsports
trailer)