Same problem with getting vacuum at idle, Vacuum advance makes motor hesitate

[Rusty 72]

Your initial question was about ported/manifold vacuum.

Like many above have answered, if you have vacuum at the ported port on the carb you have the throttle blade open too far. If you have tried different carbs and still have vacuum at the ported port you have all the blades open too far. Its not magically appearing there for any other reason.
My thought is that they have electronic chokes and you haven't turned them off thus forcing the throttle open too far.

Turn off the choke, close the throttle to a square and adjust the timing to get your 800rpm.

 

[pedal2themetal]

Y
My thought is that they have electronic chokes and you haven't turned them off thus forcing the throttle open too far.

Turn off the choke, close the throttle to a square and adjust the timing to get your 800rpm.

HI ah NO..Turning off the choke would cause the choke to be closed all the time. the electricity is what opens the choke. it powers the heater core in the choke and causes it to open as it warms up...
good luck
tim