[dmjlambert]

The behavior you describe of the regulator makes me wonder if the pressure adjustment should be made with no pressure in the system, adjust part of a turn then start up and test the pressure, repeat. The manual doesn't mention that, but it would not surprise me if it worked that way. It may be worth a try. Others with more experience may know better than me, so if my idea is just wacky you all can just tell me.