Hello to all. I have a X585 with 10 hours on it. Traded up from a JD345. I really like it except for one enoying problem. Ocasionally the tractor goes into a mode where the rpm surges or changes by itself like I was adjusting the throttle. In this mode the tractor is not very useful to say the least. I have tried various things like changing throttle position, playing with hydraulic levers or stopping pto but usally just shut it off and restart. I have heard complaints of this nature before on other forums but don't know the fix. This engine is fuel injected. Anybody with any thoughts?