Demon carb setup help needed.

I bought a demon carb.....woe is me! Thing ran but not real good. Tried all the tricks. Square transfer ports,. Cracking the secondaries with said hidden screw.. does it have a vent in the air cleaner stud boss? Thing would flood every other day. Realized there was a bit of sliced O-ring hanging up the needle in a random manner. It was still connected so it just floated around the seat until it would finally catch it open. Tried 3 different needle seat o-rings and all of them were sliced when I took them back out. Suspected a defect in the seat groove depth or something as they all sliced in the same manner. Put a holley DP spreadbore 650 back on it and it ran way better with no more flooding. Get those transfer slots square, about all you can do with them. Then monkey with the secondary to get a clean idle. There are good catn guys in here, I think one symptom is if you don't get any odle results with the mixture screws, there is another circuit issue.