andrew phillips
Well Known Member
Superior IO-360. I was thinking of turning down the oil pressure a bit on my engine as it runs near 100 psi most of the time. I had a look at the adjuster. There is a slot for a standard screwdriver and a castle nut with a pin in it. The procedure is outlined in tin the operator manual. I had assumed that the castle nut was being used as a jamb nut to lock the adjusting shaft in place. My castle nut is about 3/16" away from the block. I don't know if this vibrated into this position or if the nut is there for another reason. Any info would be great!