My shoebox is shutting off at ~3900psi. The gauge I am using is brand new and checked 5 days ago.

I would like to be able to get the full 4500psi into my 88cf airhog tank.

The instructions are very vague in the adjust area......they don't tell you which way to go to increase shut off. I am running ~85-90psi input (watching the gauge it stays around this range) . It has only been run for about 3 hours. I checked the cut off by closing the tank valve and letting the shoebox run untill it shut off, which was about 3900psi.

Which way do you adjust the collar (in or out on the shaft) to increase shut off pressure??