Without an exhaust analyzer, your ears are the tool... turn in 'till the idle drops,.. turn out 'ill the engine either lugs or stops increasing,... then set it in between...
If that don't work for you, just set it 1 1/2 turns out from closed and see how it runs...

Serowbot is it closed when the screw is almost all the way out?

Thanks the 1 1/2 turns from closed was suggested by someone else too. I think I will try that first.

From the horror stories I've read about that air screw, I can't believe I was lucky enough to not have to touch it,.....fact is, I've never seen it, ....and don't want to ! But I feel for those that have had problems w/ it.

I think a better idea is,...if it don't need adjusting, don't adjust it. Don't try to correct anything much above a fast  idle by turning a screw that is not going to have much if any effect on it.

Thanks for everyone's help.

I am not touching it again.