First, don’t forget that the rubber pressure valves in the MOTOR can go bad….Once the motor has run for a few minutes, can you crack open the tank cap and get a satisfying, yet scary, hiss of explosive gas fumes? (Don’t forget: The gas cap has to be screwed down tightly, for the system to build any pressure and be able to force fuel back up to the motor….) The check valve in the pick up would not be causing the problem you describe, I don’t think. It’s function is to work with the primer button. If it is stuck open, the primer button won’t pump fuel; although if you somehow were to get the engine started, it would pressurize the tank and stay running. If it is stuck closed, NO fuel will flow to the motor, either running or with the primer button.
For the record, I just recently went through the same pick up tube, check valve issue in a 4-gallon tank. I was able, with some twisting, to get the pick up assembly off of the steel tube, at least. I couldn’t get the valve itself apart, which was probably a good thing. With the tube off, at least I could get in at one side of the check valve, which is a small, wafer-type thing, not a ball. Some soaking with lacquer thinner and picking at it with a small tool, followed by blasts of compressed air, finally made it work right.
Long live American manufacturing!
