RE: is the muffler temp the same as the engine?
I would think that the exhaust would be hotter than the engine because of the amount of continiously flowing exhaust gasses. If your engine is getting so hot that it is flaming out, then consider riching your fuel mix up. Also if your using a tuned pipe the exhaust shold be hotter the closer you get to the head. Hope you got something useful out of this response.
wra