woah sorry I misread it as an injection model.
If its a carb model check all jets for contaminates and check float height also check needle valve for correct seating.
don't touch the mixture screw without a gas analyser. its not worth the hassle.
Adjust idle to achieve 800 +/- 50
(I think that's the right idle but I stand to be corrected. either way its not a bad base level to start from.