When you beenat this a while. Factory settings mean nothing. Too many variables to throw it off. You need to get your own "factory setting" based on where you live. It's too easy. Just openup that high end the 2.5 turns. Open the carb barrel to a position that may be close to where ti should be at an idle (which isn't much).

Close the low end needle all the way. Now make sure your in a quiet area. Take a piece of fuel tubing and attach it to the carb nipple. Now at the same time, blow into the fuel tube and open the low end needle until you hear a hissing noisethere is your factory low end setting.

This does not mean it's dead on, just darn close and you need to adjust from their when you run it. There are other adjustment tricks and there is absolutely no reason why you cannot have a perfectly tuned engine