When I first got my bike it would no matter how I adjusted the idle shoot up to 3k Rpms. I would readjust at stop lights and it would be right back up by time I came to a stop again.
Not sure if its the same as what your is doing but I had a friend help me pull the carbs and we gave them a good cleaning. Thing ran like a champ after. Idle still sits at a solid 1100. I just had to repull the carbs to clean the floats today because of a flooding issue but thats because we were stripping the screws when we had them off before and couldn't get to them at the time.
Im sure more will come in with easier things to check first but if all else fails a good carb cleaning never hurts.
Good luck hope you find the problem soon I know a bike that doesn't idle well can be a pain.
1993 Kawasaki Vulcan VN750 <To Be Named Later>
Purchased Used on 05/09/2009
Dade City, Florida
Iridium Spark Plugs
New Shinko 230 Tour Masters
110/90/19 Front 150/90/15 Back
Carbs Cleaned 06/22/09
Spline Lube 6/29/09
1992 Kawasaki Vulcan VN750 <Parts Bike>