In your break in process, you actually need a load on the engine to force the rings against the cylinder walls to get them to seat. The purpose of the hatches in your bores is to file the rings to the proper shape to seal in the bores. Running the motor with no load on it might cause you to smooth down the bores to the point where the rings don't seat or will take longer to seat. So in other words, once you start the engine, beat on it...