How quickly should oil pressure come up?

Mike, do you have a vent you can open to fill your float bowl? On my Carter AVS, I open the vent, put in a little funnel, and pour in 2-3 ounces of gas. It starts instantly after sitting a week or more. Otherwise, it's crank for ten second or more until the pump fills the float bowls.
There is a bowl vent on every carb. I don't fill the carb before starting. I could and probably should but I don't.