Generator gas flow problem
My old gas generator's gas tank (attached to the bus) had gunk in it when I bought it, so I replaced the tank with one from a junk yard that was surprisingly very clean. However, there seems to be a fuel flow problem.
It goes like this: I can see the fuel filter bulb (between the tank and the engine) is full of fuel, and I start up the generator. About an hour later, it dies. I look at the fuel filter, and the bulb is empty. If I let it sit long enough, eventually the fuel filter fills up again and I can start it, and run it (for another hour only).
I done a lot of troubleshooting, and even took it to a small engine repair guy to no avail. Below is the detail on troubleshooting.
Is it gunk in the tank?: I took the petcock off and let the gas flow right out of the tank for a minute. There was no gunk, dirt, etc.
Is it the petcock?: I replaced the petcock with some brass fittings.
Is it the fuel line or filter?: I replaced both.
Is the line run in such a way that gravity can pull the gas down to the gen?: Yes, and I have made double sure it runs down, without ever going up/level.
The only other possibility might be the gas cap, the mechanic was telling me. Something about the vent in the cap, or something. Going to see if I can get another cap, but that's not easy to find. Does anyone have any other ideas?