have a 310c hoe. havn't used the hoe much this year but noticed that the throttle wants to stick. if you use either the foot or hand throttle at high rpm when u you go to let it idle it wants to stick at around 1800 rpm's. if I hit the throttle real fast it will usally go back to idle pretty well. so I oiled up all the linkage to see if that helps. going to start it tomorrow to see if it helped. could their be a problem in the injector pump?
Get someone to watch the linkage lever at the inj pump while you work the throttle. That will tell you if the linkage or the pump is the problem.