Hi Steve, here's how we do it at our shop. Run the engine roughly at idle (get it smooth)for 3 minutes, use straight mineral oil, don't overfill. Shut down and let it cool down. Run 3 minutes again at idle, give it a little more rpm to feel it out but go back to idle. Shut down, let it cool. 3rd time you can give it an actual run up, check the mags and such. You can play with it some more but don't run it for a long period on the ground. Now go fly. Run for 10 hrs and don't baby it. It will sputter here and there, just stay close to the field. Always check for leaks. After the 10 hours change the oil and filter and use whatever your normal brad of oil is (or recommended). If you have chrome cylinders expect more oil burn, they all seem to do this on us. --- stephen langford <smlangford@webtv.net> wrote: > FlyBaby > > Received engine completely rebuilt. > My A&P said I must run-in the engine within 2 > months. Have some Stitts > preservative oil. > Any suggestions on break-in? > > Steve