Bulk carby cleaner before you adjust anything.
Ive had 4ks before that did the same, particularly autos are annoying when this happens.
I found over the years they get crud in there, then get a bit choked up in the venturis, then basically people adjust the air and fuel to keep it running ok. What happens is you end up with a choked up car and limited ajustment on the carb for idle tuning.
So start with a good dose of carby cleaner, use your hand to restrict the opening on the carb while you revit with the other, to create immense vaccuum and suck all the crud out and through the motor, then it wont start once its clean so wind the air and fuel in to the factory settings and try again. It should be pretty right at this point unless you have other issues with the genral condition of the carby.
You may also have issues with the fuel cut solenoid, but try the easy fix first.