trouble shooting 01 summit

Last spring ride of the season and sled was running great. Just pulled out of a long climb to the top of a ridge and it wouldn't idle lower than around 4000 rpm. Messed with choke and cables and still @ about 4000. Turned down idle screw but really didn't help much. Decided to head back to rig. Sled still pulled with lots of power on the way back. Then at idle , still around 4000 it started to miss or ding ding ding. Like when the DESS key is not conected right. Got back to the truck and shut it down.
My first thought was a went through a reed, cracked boot or air leak. However the missing or dinging tells me it might be electronic or MPEM box? any ideas? I'd like to get working on it now before winter gets here. Thanks

thanks guys i'll start there. what do you think was causing the missing and dinging? does that happen when the motor revs under no load? thansk again.