Mark are you mad??. The guy asked a simple question Ya shore you can run engine like that. But under normal use you would stick around the 240 to 260 deg f and 120 to about 130 deg c for a 12 size engine. A .12 engines normaly runs hotter than a .21 engine i try to keep my 21 engines around 100 to 125 deg normaly about 110 or there abouts. Regards Jeremy.