[img]i/expressions/face-icon-small-happy.gif[/img] Running in is always a big can of worms but maxtenet's 1500 to 2000 down from peak gets into the ball park. But to me the only problem with that is first you have to peak out a brand new engine. It's fine for guys who've had a couple of engines and are familiar with how they sound but the poor beginner has a problem. Even so, I think our engines are a bit more tolerant than we give them credit for especially considering the number of people that take an ABC out of the box, give it half a tank close to peak then go fly. I'm sure they don't last as long though.

Of course, when it comes to running in something like johnybravo's ringed engines, that's a whole different ball game [img]i/expressions/face-icon-small-smile.gif[/img]