Small Engines (Lawn Mowers, etc.): primer bulb not filling_toro weed eater, blowup, fuel line

Question
Any suggestions? Replaced cracked primer bulb and return line.  Bulb will not fill. Swapped lines, bulb still does not fill.  Fuel comes up long line regardless. Checked fuel/oil combo=good. Able to start by applying fuel to open carb.  Running out of ideas...

Answer
The bulb actually pulls fuel through the carb, then returns to the tank, and must be hooked up in that way, so you might double check that.  The fuel line that has the filter should go to the nipple
closest to the cover on the carb held on with one screw.
Give me your model number and I can look at the blowup for any other ideas.