We're very conservative. We'll spend an hour or so, and nearly a gallon of fuel to break in a ringed engine .60 size and smaller. We start out at full throttle with the engine as rich as possible and still running, and then grandually work towards peak RPM. We'll run rich a while, lean a bit for a short time, richen for a while, and so on, gradually working the mixture leaner. By somewhere in the second tank (second 20 minutes or so), we'll have the engine just leaned into the "two-cycle" mode. Somewhere between 40 and 60 minutes, we'll have the engine leaned to just rich of peak RPM. If it will hold the needle setting, except for slight leaning as the tank drains, then it's ready to fly.

As I said, I'm VERY conservative in running my engines.