Sorry Ralph, but a relatively long break in for our engines is not a myth. I've performed far to much work in this area to deny the evidence. A 10 hour engine provides more RPM than a 1 hour engine if it was not heat abused during the break in process. That chainsaw is more heavily loaded than our gassers, AND they have some pretty well designed cooling air ducting. Plus they are carbed to run essentially at two speeds, high idle and WOT. At WOT they all run pretty rich, adding a greater cooling effect, and/or carrying away a lot more heat energy. That's why they can run hotter than our airplane gassers and get away with it.