IMO best way to set the idle mix is do disconnect and ground one plug with the idle just high enough to keep it running on 1 cyl. adjust that cyl. by turning the mixture screw in until it runs rough then back out until it runs rough counting the turns between the 2 rough points and the correct setting is 1/2 way between those 2 points. Then repeat to set the other side.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!