Hunting in dg Set

Your hunting might might be caused by backlash on the fuel rack, either wear somewhere or somebody's left something off after overhaul. When you say 'mechanical mode' I assume you mean off-load, in which case the alternator is not actually working (varying), so it might not hunt.

What will cause hunting, although you might not see it when in parallel, is that your AVR gain is set too high. If you have identical engines and alternators do some resistance checks on potentiometers between the AVR's.

Have you adjusted the droop and speed on the AVR? Have you changed fuel filters as fuel strarvation can cause hunting, as it has to go to max fuel. Did you make sure that the fuel setting was in the middle of the range before adjusting the Droop and Freq on the AVR on the control board at the engine? Did you make sure that your speed adjust on your board wasn't set to max before you started making adjustments to the AVR. I would probably do a step by step adjustment according to OEM shop manual.

dg sets air filter choack in hunting problem.