High Idle? My 80 CM 400 t runs at higher rpm after you roll off the throttle. If you rev the motor it will stay at 3000 rpm for 30 seconds to a minute then lower to @ 1500 rpm. I took the carbs apart and put in new O rings and diaphragms, it was idling at 3000 and stayibg there. I adjusted the valve lash also but no change. It starts easily, and idles @1500 at first, and drops back down to its high idle after 2-3 seconds of rolling the throttle closed at first, but after 6-7 miutes of riding, it idles at the 3000 and takes a long time to drop back to 1500 if it does at all. Adjusting the hand speed screw adjustment does nothing. Any idea?