james, Randy said (if I remember correctly) to run it in a wet 2 and then pinch the line every so often.  No 4 cycle, at least not a slobbering rich one......... ours did not take much breaking in at all. ABC construction and a good fit, so just some running to get familiar with it!  Ours did get a little better on gas milage after several flights, but the run characteristics didn't change.

Bill <><