Getting stumped here on my bike. This bike has always treated me good. Recently I noticed my header was getting hot (glowing red hot). It starts and runs just fine, very little backfire on decel with a throttle chop but nothing serious. Started off with running my air/fuel screw in. Was at 1 1/2 turns out, ran it all the way in, in increments of 1/2 turns with no change. Cleaned all the jets out in the carb and didn't notice any to be plugged. Checked intake boot for air leaks, nothing there. Any ideas?