2004 Sportsman won’t idle

Hi all! Nebie here. I have used ALOT of the helpful information on here and decided to join. Having a problem with my Sportsman idling. Here’s how it started. We were riding Hatfield McCoy s a few weeks ago and were coming out of town back to the trails. I decided to hit the creek fast to cool off a little. After riding awhile she started stalling when off the throttle. Also I would get a backfire every once in a while when letting off the throttle. It will start and idle with the choke on. It also rev’s fine in neutral. When I take choke off it just dies. Like I said it was a few weeks ago so I would assume everything is dry. Stored in the garage. Any help would be greatly appreciated!