Took Carburetor apart...now wont prime.

My Echo SRM 261-t string trimmer was four stroking and would not go into high rpms as a 2 stroke should so I took the carb off to make sure everything was clean. It all looked good (I cleaned everything anyways) so I put it back together and now the primer bulb does not work. I took it apart again to double check I got everything back right and i can not find an issue. It is as if the air can't escape from the bulb so it can suck up the gas. It feels like you are just pressing on an air bubble but the air cant go anywhere. what did I do? Thanks, DJ