I am flying a 40 size Ugly Stick Arf. I was runing an MDS 58 2-Stroke but had a very bad engine vibration. Ipulled that engine off and installed a New 52, new prop. Ran several tanks of fuel thru engine during breakin on my engine stand and no
vibration problems at all. Mounted engine on airplane, and the damn thing wants to crawl all over the ground. Don't understand why, prop is balanced.

Craig