2004 Yamaha Bruin 350 4x2 high idle when hot

[wjslam]

New to forum and ATVs, so here goes. Bruin 350 has been rarely used, especially recently. Changed oil and filter, new plug, cleaned air cleaner and filled with fuel w/ Sta-bil added. Rode for 1-2 hours with no problems. When coming to a stop and left idling in neutral, idle increases to perhaps twice normal rpm. Jabbing throttle has no effect...when it returns to idle, still idles high. If I shut off the motor, it backfires once through exhaust pipe. When restarted, it idles normally for 10-20 seconds and then increases again. I don't want to jump to any conclusions at this point, and I do not have experence with small engines; however, I'm pretty good with Ford FEs. I appreciate any help/advice!

[CK1999_400ex]

check and make shure its not sucking any air between the carb and cylinder(motor) have had this problem on several quads