Probably your plunger did nt seat properly due to the installation technique, or there is dirt in the well. Carb cleaner will not do it any good....if there is dirt in there, it need to be cleaned out; carb cleaner and dip will just push it down in and will be hard on the pump rubber (and any soft seals).
BTW the ball is there to prevent air from being sucked back into the pump shot cavity rather than fuel, as the pump retracts after each use. The ball and weight rod need to move freely, and the ball needs to seat well as noted by Trailbeast; otherwise, it sucks in air. Refer here:
http://www.edelbrock.com/automotive/misc/tech-center/install/1000/1404_manual.pdf
