I took out the idle mixture ? screw & shot starting fluid in & replaced it (2&1/2 turns).
Unless you have one of those 2010 CNS carbs that has the choke cable coming out the top with the throttle cable and a second turn screw (not likely) there is no separate 'idle mix air' screw, they are even capped off on the new CNS carbs so there is only the idle set screw.
All the idle screw does is physically hold the throttle barrel up to the desired height for idle.
Twist it in for a higher idle, out for a lower idle.
Where the throttle cable goes into the carb I turned it plus I turned the knurled lock knob (lost my baseline) with no change either in idle speed or stopping it from dieing.
The only thing the cable adjusters do on each end is take slack out of the cable, not set the idle, trying to use them for that is a very bad mistake, they are just to take any slop out of your throttle twist response and there should always be a little slack..
Pull off your air cleaner and look inside.
You will see the barrel that goes up and down when you turn the throttle.
The idle set screw just sets how far down it will go.
My guess is you have an NT carb (just one cable from the top) and the choke is a lever on the carb.
See the round plate that comes down over the air intake?
Does it open all the way with the lever down and go up when you lift it?
It has a screw holding it, chances are yours is loose and the choke plate is blocking your air flow ( or you just have the choke on), you won't idle well with the choke on ;-}