I never break in my engines, I put em on the planes and runs em. Here's my latest 2 stroke going to work right out of the box on 100:1 full synthetic. I tried to run petroleum based oil to help wear in the piston and cylinder quicker, but it slobbered oil residue on the plane, and that is not acceptable. It loves the 100:1 mix, there's no residue on the plane, and it runs like a watch. I'll break it in next year if I have the time. lol
http://www.youtube.com/watch?v=TbeQKnL0sek