The best way to set the idle mixture is to use a vacuum guage and set the screw to as much vacuum as you can get. If you have no guage, I usually turn the screw in all the way and then turn it out about 1 1/2 turns. If it still runs like crap, there is something else wrong. Try shaking the throttle shaft. If it has lay, it is worn and there is no fix for that. I had to get a new carb. I screwed up and bought a Holly/Weber set up for the A14 but it is a screwy carb and I do not recomend them.
Mareo