You may have 2 balls one is under the acc. pump and one is under (i will call it a power valve).
You need to look at the schematic (blow up of the carb. that came with the kit) and find the "T" shaped part on the diagram. The "T" shaped part is pinned (sp) (hammer and punch) into place and you may have not removed it from the carb. body. Under the "T" shaped part is a spring and a check ball. Use a pair of needle nose plires and pull out the "T" shaped part turn over the carb. and dump out the spring and ball. To install drop in the ball,spring, and T, push the T in and with a small punch and hammer repinn the T into the hole.

I didn't do it, no one saw me do it, you can't prove anything! "Bart Simpson"