Thank you for the Info frankflyboy1.

I checked the balance on the rotor and found it to be very slightly off balance, but I guess at high revs just slightly off is enough. To bad... it was a great running engine in spite of all the bad reports I've heard about Rossi. I'm going to try and get my hands on an os .91. If not I've found some used bvm .91s but I've read that the bvm over revs in anything other than a bvm fan.

Just a few more questions though. What’s the best way to balance an impeller, scrape the blades like a prop, add led tape to the back side of the blades? I have a du bro precision balancer for balancing. Is there a better balancer to use for balancing rotors?

I hope to get my skyburner back in the air soon. It sure is a sweet flying design. Easy to fly, smooth as silk, and hauls some balsa across the sky. Not as fast as I was hoping though, about 85 mph tops if I had to take a guess. But it sure looked good doing it. If I could get my hands on a good os .91 and the right pipe and get about 22-23k revs I just might be able to reach that 140 mph mark the designer claims it will do. YEEEEEE HAAAAAA!!!!!!

Thanks again