9. Clogged Petcock

Disassembled Petcock

Yes, your petcock* should have a screen on its fuel intakes to keep it from clogging, but rust particles from your tank’s innards aren’t the only thing that can clog the petcock’s internal passageways. Corrosion within the valve itself can bung up the works. Try tapping the petcock with a screwdriver (or a small rock if you’re stranded in a parking lot) a few times to see if you can jostle the gunk loose. Hopefully, you’ve got a filter inline before the carbs themselves are clogged. Also, the vacuum line from the engine to vacuum controlled petcocks can dry rot, crack, and leak, keeping the engine’s suction from opening the valve. A little electrical tape over the crack might get you home in a pinch.

*Get your mind out of the gutter and back into the fuel system where it belongs. A petcock is a fuel control valve that turns the flow of gas off, on, and to the reserve position.