Hard starting after carb overhaul

Mikuni BS34s on KZ750-4, 117.5 mains, 35 pilots, freshly synchronized. Very snappy response, but demands ether when cold... if I recall, I set the screws 1.5 turns out.

Ideas?

2 turns out would be a better starting point. You may need to adjust each individually from there.
When you were cleaning the carbs, did you pay close attention to both the pilot, and the starter circuits?
Any vacuum leaks?
In order for the "Choke" to function, as it is actually an enricher, don't touch the throttle when cold. It needs that high vacuum at the engine side of the carb to pull fuel through the enricher.

Carbs were separated, soda blasted and ultrasonically cleaned, all passages blown out.

I'll try turning the air screws out another half turn...

Motor Head wrote: 2 turns out would be a better starting point.

BINGO!