I put a used fuel tank in my 1982 Brat. My old one was rusted inside and would clog the fuel filter within minutes. The replacement tank seemed clean and rust free. I put 3.5 gallons of fuel in the new tank the tank after installation. The Brat fired right up but only because someone was adding liberal amounts of starting fluid directly to the carb. I disconnected the fuel lines at the newly installed fuel filter and they were dry, no fuel in the fuel filter. The nearby fuel pump sounded as though it were functioning properly. I then disconnect the fuel line that ran from the tank to the fuel filter and it was dry as well.
Should 3.5 gallons be enough fuel to spill out of the outlet of the tank due to gravity alone?
If that metal section of fuel line from the bottom of the tank to the outlet is clogged are there any recommended options for clearing the obstruction?
Would any of those options potentially damage the tank in the process?