#1 Cylinder seems dead.

You got fuel to the top of the sight plug? you got pressure issues or a bad needle seat. I never liked the adjustable regulators. How do you have it plumbed, In the bottom and out the side with a gauge on the other side? IIRC you loosen the adjuster to lower the pressure. Carb is not going to isolate a runner by itself, there has to be a valve train issue...just look at #1 intake rocker while you cycle the crank. Should move equally.