Alot of top tuners say engines run between 200 and 300 degrees. Racers will tell you keep it around 200-220 deg. During outdoor season that I find to be too low, it has NO low end power. I use spit test to keep me and my temp gun honest. Pro tuners say tune to track, not temps, just keep it in the range. I use spit test to see what temp it likes and doesn't like. Very little sizzle and as far from 300 as possible.