1990 Ford Probe factory set air fuel adjustmet

Mt GT 2.2l Ltr Turbo has a factory set screw adjustment for fuel air mixture optimization. I learned too late after purchasing a Ford Shop Manuel that I should not have attempted to fine tune this setting. I obviously am now set too rich. The spark plugs are indicating soot and there seems to be more heat coming from the upper engine, although the analogue gauge does not indicate an excessive temperature reading. Please advise. Also please indicate whether lean is counter clock-wise or other.