with the bike at idle turn the screw in until that cyl. runs rough, then back out until it runs rough counting the turns. The right setting is 1/2 way between the 2 rough spots. I disconnect one plug at a time to do this so it is easier to hear when that side gets rough. You will need to turn the idle up slightly so it stays running on 1 cyl. Ground the plug wire you disconnected if you use that method.
This chart shows when the different circuits come into play.
