Last year I found some metal chips in the oil when I changed it. An engine strip revealed what I expected - the contact points on the arms of the governor weights had worn, a result of fitting a heavier spring to work against the governor to increase the engine rpm. ( Maximum rpm went from standard 2200 to 2900.) After repairing the arms I got smart and lightened the weights by drilling them, thinking that I could use a lighter spring and get even more revs, the target was 3200. The end result was that a spring not much different did get me 3200 rpm (no load). However, the result on the road was not good, the only time it got near 3200 was going downhill, the engine now hunts badly at idle and every so often goes limp at 'full' throttle, it's almost as though I'd rolled the throttle back to about half way. It appears that lightening the weights was not a good idea. Has any body out there got any ideas about reducing the load on governor components while maintaining the desired engine performance?
( I am fairly certain now that I won't get a useful 3200 rpm without alterations to valve and injector timing but just reducing component loading and wear would be a good start!) Cheers, Brian H.
Governor - Kubota KND5B
Moderators: Dan J, Diesel Dave, Crazymanneil, Stuart
Re: Governor - Kubota KND5B
Further to this issue with the governor, I have done some research on 'electro-mechanical' control of the fuel system. The plan is to use a stepper motor to control the pump fuel rack, this in turn is controlled by a micro processor which has 2 inputs, throttle position via a variable resistor and engine rpm via a proximity sensor picking up a pulse from the hand crank fitting on the end of the camshaft. From what I understand of what I have read about the components, it should work. Electronics are not my field of expertise, your thoughts please.