I am going to guess: either the temperature sensor for the engine coolant is giving the computer bad data, and/or the TPS (Throttle position sensor) is either faulty or out of calibration.
The high rpms are causing the clutches to spin, which WOULD make it hard to shift. Lower the rpms and it should shift fine.
(You have fuel injection, and not a carburetor)
Were there any changes to anything around about the time that the high idle started? Anything in the repair history that would be significant?
2007 Sportsman 800
1500 miles, mostly at Hatfield-McCoy trails, WVa.
Last edited by WalterS; 07-03-2011 at 08:56 AM.