OS engines: one tank of fuel on the ground, adjust needles, and fly.

I found out that it is important to go easy on them for the first few flights. Keep it a tad rich, avoid nose up flights like they say in the manual. I ignored both of these on my most recent engine, just for giggles, and resulted in a dead stick after pushing the engine for about 5 minutes.

Of course I later learned the fuel I was using is garbage...