I had come across this writeup for the WUR some time ago, they say to tap the bottom of the regulator in towards the center if the pressure is low, but you need to take the WUR apart to drive the regulator down if the pressure is high. It appears the WUR they used in the writeup didn't have the allen screw on the bottom. The allen screw seems more precise than tapping in/out for adjustment.
http://www.landsharkoz.com/images/pdf/wurfix.pdf
The writeup does do a good job of describing how to check the fuel pressure.
It does have a nice writeup on how to check the fuel pressure too.