Hopefully someone can help me out with this. Whenever the bike sits at idle for a while the engine will start to slowly creep up from 1000 (where I set it) to about 1500-1700 rpm. This is just sitting there, no throttle, no choke, no nothing, in gear with the clutch in or in neutral with the clutch out. My plugs look fine, and the engine is warm. In fact I think it happens more often when it is warm. I can snap the throttle and bring the RPMs back down, but after a little bit they'll climb up again. I can do it twice at a light. What's going on?