A glowing header and backfires like that are almost always caused by running lean/hot. The choke makes the carb run rich for cold starting. With this in mind, a sticking choke would keep the idle high but, it should not be running lean. When you are fixing the stuck choke check out your pilot air screw and make sure its not set too lean. Then again, its air-cooled so the racing idle could be causing the heat problems.

 

yeah, it really races, only takes a minute or two to get red and ya gotta shut it down. I haven't gone back over to check it out again, perhaps tomorrow, maybe I didnt' seal the carb on intake boot well or I missed something else...

 

Check your throttle plunger dude, i just rebuilt my snowmobile, which isn't a wheeler but has carbs, and when i put it back together i had a the cable fed through the plunger plate wrong, check out your plungers and cables. Hopefully you'll figure it out.

 

parts finally came in, new gasket for bowl, heating element, air filter. put it together and same thing. idle adjustment made no difference, nor did lubing choke, or fuel/air screw. we were stumped, so I looked for the obvious, sure enough, the throttle cable was kinked, duh! she's running great now!

 

Your welcome.
simple things first.

Two people asked me to fix things for them. A Chainsaw and a snowblower. Both didn't have any gas in the tank. HAHAHA. Simple things first.

Glad you got it figured it out though. Have fun riding now.