In the B60 manual it says that the Knurled leak-off valve may be closed if the engine is hunting at idle and should be open fully, is this the Fuel pump bleed screw? And I take it to open is anticlockwise, these sound like a silly questions I know. Just need a bit of clarification.
This is one that the writers of the manual got wrong. Here is what the Kubota application manual says. "Always keep the air vent **** on the fuel injection pump closed except when air is vented, or it may cause the engine to stop."
Clockwise is closed and counterclockwise is open. It is not necessary to crank down on the knurled knob hard as the needle valve inside is very fine and will seat properly with ease.