the second line going into the feul tank is the prime line........the small (most of the time white) piece of plastic is a one way valve..... my bet would be on replacing the one way valve. I replaced feul lines on a weedeater one time and mistakenly crossed the bulb lines........thats how I learned.
Wigglestick
April 2010
Its either a fuel blockage from the fuel tank ( replace fuel filter in tank ) or screen blocked in carb ( remove carb and clean internal filter under pump diaphram ) or the non return valve in the carb is stock ( remove carb and clean out ) or non return valve in the primer itself ( replace primer )
Husqvarna man
April 2010
I can answer this question...
25 cc craftsman weed trimmer that wont stay running?