I just purchased a trx 400ex. It is in great shape, however it sat for over a year. I had it tuned, new carb kit, oil, filter and tires. I drained gas and put new gas in. The shop that did this said it was running great, however it would stall at idle and they said it should clear after gas is drained and replaced. I did that and rode it for about 15 minutes and noticed the exhaust pipe at engine was getting red? It definetly was hot! Not knowing much about what it could be, and hoping someone can give me some ideas.

New to this.

JET

 

I posted this where you asked the first time.
If your header pipe glows red under normal riding conditions, not when parked and idling, you are running lean and need to rejet.

 

Thanks, it is under normal conditions, although is also backfires when it either stalls or I shut it off.

 

You might be a little lean. A lot of times, folks will do mods that aren't obvious like a higher flow air filter or uncork the exhaust, and fail to rejet at all or not jet properly.

I would richen it up and then work my way down until it is better. Remember, a lean engine will seem to run better than a properly jetted one, so don't make that mistake!