Having trouble with a 07 sportsman 800x2 the bike runs great but the manifold where it connects to.the down pipe is glowing and is over 1000 degress. I have automotive experience and apprears to be lean from.what i know No leaks at intake sprake with carb clean and double and tripple checked the black intake manifold that connects to.the block. Manifold had a crack in it bit welded it all back and brazed it to give it extra metal in that area. No codes and runs like a champ just worried it might be lean and dont want to.ruin anything. I just bought it. Not.sure.ifnit did this before as after getting on it first time is when i noticed the cracked manifold. I wrapped the pipe at rhe leg and reinstalled it all. Compression is same cold and same after the ride whwn the manifold is glowing. Replaced plugs before i got it back together and added k&n filter. Any suggestions that could be causing this.

 

Update to help here is the manifold and plugs