BTW guys... it was read by an optical tach check so we do know that the 4K is an accurate number. Good to know it it probably just a governor adjustment.
Thanks for that info. It's an involved and technical proceedure to set the adjustment of the Fuel Injection Pump and Govener; way to much for this discussion, and quite possibly not even necessary as the injection pump appears to be operating without complaint. The motor appears to be operating ok, there are no reports of any other issues except high rpm's in neutral, which is what the manual calls for; verification at no load test. Why not break the wire on the Maximum speed adjustment bolt to lower the no load RPM's to 3600. Then rewire the maximum speed adjustment bolt. The wire I would asume is an antitampering concept. Another alterenative as Ed pointed out in an earlier post is to not run the engine at full throttle, which imho is as easy as it can get to solve this issue.