alot of motors WONT run without a choke for the first min or so of idling.
run your idle screw on the carb IN until it will run and warm up.
After its good and warm idle it back down with the choke off.
then adjust your mixture screws till you get the highest idle again.
adjust idle screw and repeat till you don't get a higher idle when adjusting the mixture screws.
then the carb will be adjusted properly.
now.....the choke is not a vacuum operated device.
on the original manifold that the carb came off of had a bi-metal spring connected to the choke linkage.
The way it worked.....is
Before the motor starts the choke is completely closed. as soon as there is manifold vacuum a diaphragm pulls the choke open Slightly
As the motor warms up the bi-metal spring releases its tension as heat off the manifold effectively changes its shape.
and saying that.....you need a manual choke.