I remember three dashpots-
2 on the AC end of the gen set.
1 on the loop circuit.
Is this "DP" dashpot the one in the loop? One other thing you might look at, is the brake. Make sure it's not dragging.
Got oil in the gearcase?
Exactly...That's how I used to set them...Single phase the AC to set the AC ones.
On the DC you drop the brake, measuring current with amp probe. I think trip was a bout 150%, but I may be off. Adjust pot, and cover with just enought dashpot oil to cover tips on the plunger..
Ah...So long ago...