RE: Beginner speed?
Don't feel bad, the worst running engine I've ever owned was an evolution.
Bought new, properly broken in. I have been running model engines for twelve years and I never could get that hunk to run reliably through a full tank. I tried it on the plane, I put it on a test stand. I tried 10% and 15%. I tried props of all sizes and several tanks. I changed fuel lines more times than I can count. I even took the engine apart looking for the cause. I doubt that I had a single run that the engine throttled correctly. Most of the time the engine started easily, but refused to develop proper full throttle power no matter what I did to the needle valve. If it did, it would either turn burbling rich or die out lean within the next five minutes. This was replicated on the plane as well as on the test stand. The needle valve was not loose, nor was it ever damaged in a crash.
I was thrilled to get rid of it and wouldn't run another one if it was given to me. Seriously.
I have talked to several guys who love them. I have also talked with a few who had experiences similar to mine.