Thanks John and John. I counted the revolutions seating the L and H screws. Both were turned out one and a third. I turned both out one and a quarter. A few pulls later and the saw was fine, good acceleration and consistent idle. I didn't have to touch the screw in the MIX hole. Very happy. This is an older saw, all metal and made in Germany. I got it because my MS310 was beating me up.
I tried the arborist and forestry forums. Got to the point where there was too much advice.