I had a major leak where the fuel line comes from the gas tank so changed out the fuel lines and gas tank O-ring. The leak seems to be ok now, but now, when starting the scooter, the fuel pump hums and the fuel gauge is pegged at empty. It will start, but it sputters for a while then dies.
I suspect I flipped the lines that go into and out of the fuel pump. Here's my setup: Fuel tank --> black side of fuel filter --> red side of fuel filter --> lower port of fuel pump --> upper port of fuel pump --> carburetor. I'm sure there is air in the lines too.