Okay so I pulled the plugs and tested compression as i thought they all tested good. 120-133. All my plugs were pretty black though. So I started it up and warmed it up. I tried adjusting the A/F screws and found the best quality idle at around 540* turns out. That is about 360* in from where it was set.
Remember that these control low speed fuel metering ONLY.
In order to change high speed fuel metering, (depending on the carburetor) we need to access the carburetor interior.
Another thing I noticed, when I ran both screws all the way in, the engine continued to run when I thought it should have died. I am still running the carter AFB's. let me know what you think of this.
If you closed off the low speed circuits, and if this engine continued to run OK, it's likely getting fuel from another area.
In which case Kim's carburetor float adjustment idea comes to mind.
Again..... swap carburetors.
The cost to swap them is two new base gaskets only, and a bit of your time.