Originally Posted by Scott Fisher

Don't really tune to temps. Some engines I have never put a temp gun on. One thing our team manager has been doing regarding temps is tuning by temp change. Warm the engine and tune it to run well with some visible smoke. Temp it. Run some more, then temp it again. What he looks for is the change. IF the temp continues to rise eventually the engine will lean bog. Thats too lean. He looks for it to stabilize. We just want it to run as fast as possible, without it getting so hot that the motor lays over near the end of a tank, or eating plugs. Lots of things will have an effect on the engine temps so I don't want to put a number to tune to, but I would say in the 250-280F would be a general area. Performance (good/bad) will determine what the right temp is. If it runs fast (not too rich), doesn't eat plugs, doesn't pit the piston or button, and doesn't lean bog, it is tuned correctly.