my experience with older boat, same fuel issue couple of times problem the same plugged line. Fuel starvation, I had to remove all the lines from the tank to the carb. found one tube blocked with particulates from fuel filter built up on bend and when finally found looked like the butt end of a bee.
Like posted before dump the bulb remove and check all your lines free and clear. Run boat until it stalls then crack the carb. top and see if bowl full of fuel or pump the throttle and look for fuel injection. Replace all filters especially the bronze one in the carb.
