Update: Uncoupled Hydraulic Motor
OK, I've uncoupled the hydraulic motor to remove any effect of the hydraulics on the revs.
See video.
In my introduction I say that uncoupling the motor had stabilised the revs but then my test on camera completely disproved that as the RPMs were all over the place.
- It still over-revs at even half throttle (WSM has Max Revs at 2400RPM)
- It still takes for ever to increase or decrease RPM when the throttle is adjusted.
So, while we may still have a hydraulic issue, I think we need to sort out this unstable RPM issue first.
Here's what I've done so far:
- emptied and cleaned fuel tank (had water, rust and gunk)
- replaced fuel filters (clogged with water and gunk from tank)
- replaced fuel lines (lines were brittle) -
- tested injector pump - pumping fuel evenly from all three pumps. Tested straight from outlets and through injectors.
- Tested fuel slider rail. Full and free movement.
- had injectors tested - tested ok
- bled injector lines
- replaced engine oil and oil filter
- replaced thermostat and coolant (thermostat was stuck open)
- air filter had already been replaced - exhaust is clear
- checked governor spring, forks and flyweight. Worn but nothing broken or missing. All free moving.
- cleaned and flushed hydraulic tank, replaced both filters (both filters were very clogged), filled with new oil.