Turning them in on all models reduces fuel flow to the engine. Backing them out increases fuel flow.
It is possible in many cases to screw the idle mixture screws all the way in, and the engine will not stall out. This is OK, as some fuel still gets to the engine at idle past the transfer slots.
You still should be able to slow the engine down by turning the mixture screws in. If not, it's getting too much fuel from the transfer slots, or dripping off the boosters, leaking bottom plugs, etc....Cliff
