1986 lt250r idle issue
New here and to quads completely. Picked up a 1986 lt250r and the guy told me it had been sitting for about a year and most likely the carb needed to be cleaned to run. So I drained old gas, put in a new spark plug. Took out the carb cleaned it out. It will kick over with the throttle all the way open than will idle perfect for a few minutes. Than all of a sudden will revs all the way up like I'm pinning the throttle all the way down. If you kick it into dirt get it comes back down and idles fine again. And can rip around fine.I've been told possible air leak? Just looking for any suggestions before I spend money at a shop.