I have a 2000 Honda Rancher ES. Long story short. The past couple of months my ATV has had a hard time running at idle. So I drained the gas from the carb for winter. Well the other day my dog decided to go for a nature walk on her own across the rice patty by our house. Being we we're in a monsoon for a couple days it was wet. So I pulled the ATV out of the garage to go get her. I knew it wouldn't idle just enough to get it running and get this pooch. After about 5mins I got this thing to purr, I think I got the trash out of the carb and whatever was plugging it. So I'm good to go so where this is heading the exhaust pipe that comes off the head was turning bright red up to the 180 ehh a couple inches but not past the 180. Being it was later in the day close to dark this was more visible. I've owned this TOY all it's life and have never noticed this. Is the typical or anything I should worry about? No difference in performance or any sound of blockage. Cold this be a carbon buildup burning off?