First off the instructions they give forget. The way they say to do it you'll never line out the bubble count.
Close the needle valve (turn clockwise till it stops), but not to tight you don't want to damage the seat.
With your gas tank open all the way, turn the black knob on the front of the regulator clockwise until your right hand gauge is set at the operating pressure you want.
Start to open the needle valve to the bubble count you want.
Check every few hours for the rest of the day and by tomorrow it'll be running like you want it.
Follow their directions you'll NEVER get it set