Here is my B46 experience, I have the Zama carb BTW:

Problem 1: Would not start easy because the engine would not prime. The solution was to cover the weep hole in the choke butterfly with JB Weld. It took me over a year to figure this out. I figured this out by shoving my chicken stick (a big thumb would also work) into the carb intake and watching the gas flow - with the ignition off.

Problem 2: Could not get it to idle low. The solution was to fully remove (instead of backing it out) the original mechical throttle stop - dumb! Again took me over a year and this was really frustrating as I thought my problem was low end fuel mixture.

Both problems could have been easily and quickly resolved if I had aggressively pursued them.