ok i have done a very intense cleaning and rebuild of my carb. 250 inline single barrel. truck still will not run without the choke on, even with it on cant pull a hill or get above about 45 mph. i checked vacuum in the intake and its right on 20, that is with the choke on because thats the only way it will run. if you turn choke off you can hear a sucking sound from carb and engine dies. i have checked all possible vacuum leaks found none. could this possibly be in the ignition timing??
