The same engine was used in the JD425 garden tractor with the same issue. There is an update kit and any service replacements should come with a metal gear instead of the poly gear. Aside from the cam gear issue, these are really good, long-lived engines.Pete1313 said:Do the reels engage, do the lift cylinders work to lift the cutting heads, then check the condition of the reels and bearings for play, any issues driving forward or reverse. But the main thing is how many hours it has on it. From what I've read is the Kawasaki engine in these units will need an overhaul at 3000-3500 hours. They have an oil pump driven by a plastic gear that wears out around those hours.