No fuel flow through trimmer caburetor

My troy-bilt trimmer will start but stops running after about 5 seconds. The fuel lines are clear and the primer will pull fuel from the tank and return (verified via connecting fuel filter and return lines to the primer only and priming). The fuel return line is connected to the long connection at the primer. The fuel filter line is connected to the bottom of the carburetor (L shaped connection) and a fuel line is connected between the top connector on the carburetor and the small connection on the primer. The carburetor has been throughly cleaned several times, has new fuel pump diaphragm, new metering diaphragm, new metering spring/lever/inlet needle as well as new pump gasket, metering gasket. All gaskets and diaphragms are installed correctly. This is a zama carburetor on a troy-bilt model TB70SS. Fuel will does not flow out of the connection on top of carburetor to small connection on primer. Any fuel in the primer is pumped into the fuel tank. Problem started after fuel line leaked during use. Cut the bad part of the fuel line and reconnected. Did not replace fuel lines, but cleaned fuel filter, tank, and lines appear clean.

 

i messed up and took all lines off before i bought lines and primer bulb. it seem i just can't figure it out. help if you can. tboz@centurytel.net