There are 3 adjustments on the acc. pump arm. The one closest to the top gives you the most pump shot.
Just my .02 but I personally don't like Performer carbs because I've had 2 do just what yours is doing and I couldn't work it out because there's no adjustment on the secondary air door. It's a fixed setting. The Thunder series is better cause it has an adjustable air door modeled after the old Carter AVS.