We car guys use a method that's popular with the racers. It's called "Heat Cycling". You get the engine up to temp (190-200) and run it for 5 minutes. You shut it down and let it cool all the way. You then repeat the cylce two more times (total of 3, 5-minute bursts). The next 15 minute set is similar, but instead of 3, five minute cycles, it's 5, three minute cycles. After a this total of 30 minutes of run time, the engine is ready to "race tune".

It seems the engines run stronger and last longer (5-6 gallons on the good quality ones). Our engines are typically from .12-.21-.26 in size. I don't know if engines of different sizes or different applications (ie planes) would be any different.

Just another perspective. It's working good for us.

-RobH