I have read more than once that engines wear the most after start-up and while they are getting up to operating temp. My theroy is the faster you want a engine to break in is start it up and run it up to running temp and let it cool down and repeat this as much as possible. Ever hear the saying" the more I run it ....the better it runs....like after many start ups and use. Diablo you gave us some very good facts, I am sure you love engines maybe more than flying????? Best Regards Captinjohn