Shouldn't. I sure hope not. lol. I put a couple coats of VHT Aluminum color spray paint on the muffler which is the same stuff I used on the can, Then a couple coats of another High Heat spray paint with the green. The VHT is supposed to be good up to like 1200 degrees and the other stuff only like 700. I got the idea from others that have done it on the site. I know with no snow I will never find out and plus it isn't running right anyhow.
I did mine before the thanksgiving holiday, it looked the same as yours. I rode 150 miles near chrystal mountain and when I opened the hood its was black about half way from the motor outward. I also used 1,200 degree paint and primer and baked it in the oven as reccomended. I ust think its too hot for it. Im thinking powder coating is the way to go. it was still worth it, it added years of life to the pipe having some protection on it.