Primer bulb won't prime!

I have another featherlite sst25 that I am working on. Today I cleaned the carb and changed the fuel lines but now there is one problem. when I go to prime the carb it does not suck in fuel, at first the bulb would push down and be stuck there like there is a vacuum. I fooled with the gasket and reed valves and now I can push it all day and nothing happens. now it just pushes air and whistles. I have tried priming with both the gas cap on and off.

I would like to try to get this thing fixed and out of my way so any help would be appreciated. Thanks!