Zep 45 will do bad things to the diaphragm if it got in the regulator. Now lets break this down into parts. Regulator should start at being flush and about 2400 RPM you are running on the regulator which will make the low speed needle just about useless. The low speed needle works reverse of the other settings on the engine as it is an air bleed so the screwing it in RICHENS the mixture. You might want to pull the regulator apart and make sure the diaphragm is not out of shape and that the plungers is opening and closing without hanging.