Quick fuel Q750 tune ?

I agree. Doesn't matter if its new. Could be a shaving from the drilling.

If you have a setup the really wants stagger jetting, could be reflected in the idle mixes.

Also if your setup doesn't really need the extra fuel from a four corner idle, then 1 turn out is too much. There is no normal for a carb. There's a range in which it will respond to what the engine wants. If its down around 1/4 to 1/2 turn out on each mix screw, or 2 turns out on each mix screw - then somethings up. Otherwise its just a fuel trim adjustment for what the engine wants.