i'm not sure what motor you have, but i think running constantly @ 280+ degrees fahrenheit can't be too good. you can actually smell the metal burning.

anyway, i was lucky enough to have don waller help me break in my ws72. the temp @ which you break in your motor is going to dictate how hot it will run. so, if you break it in cool, your engine will run better @ cooler temps. on the flip side, if you break in your motor hot, you'll have to run it hot to get it's max potential.

my c-5 ran best around @ 225 deg f. my ws72 runs best around @ 195 deg f. now the ws72 has had only about 1/3 gallon through it, and i run it pretty rich. even though its still pretty rich, it has a tremendous amount of power. i'm sure if i tune it and lean it out a bit, i'll really feel the power. right now, i'm trying to not overwork it until atleast i've gone through 1 full gallon. even then, i'll try not to let it get past 240 deg.