I have a problem I'm hoping someone can help me with. I bought a new Harbor Freight/Chicago Electric 5500 generator several months back. I use it for backup for utility power, as we live in a rural area in the Sierra Nevada foothills.
Anyway, this month when I went out to give it it's "monthly run" (just start it, warm it up, verify generator operation, charge starting batter -- 15/20 minutes), it only ran for about a minute before stopping. After restart, it ran, say, thirty seconds; next restart was, say 5 seconds. If I try to start it again, it'll only run a couple of seconds. If I let it sit for several hours, then the thirty-second thingie starts all over again.
I have verified that it is not getting fuel. As it's about to die, I can turn on the choke and it will continue to stumble along for a few more seconds.
I have eliminated any water in the gas (there wasn't any), cleaned out the float bowl to remove any foreign debris, verified that the valve and hose going to the carburetor will supply a good stream of fuel.
Being relatively engine-wise but not being familiar with the details of this engine, I'm stumped. Two things that I haven't checked might be causing the problem.
The first does not seem to be the problem, though, given the symptoms, and that's the low-oil pressure system. The low-oil sending unit (which I believe is mounted at about crankshaft-height on the side of the engine block) wire goes to a "segregating unit" (whatever that is, about .6" square, metal case) and then splices into a wire that connects the coil to the ignition switch. Consistent with other small gas engines, it appears that the coil is a magneto unit, with a hot lead going to the pressure switch and the ignition switch, whereby if either were grounded, then engine would no longer run.
The second thing, which I consider more likely, is a "thermo sw" (thermostatic switch?) and a carburetor fuel-bowl solenoid. I can't follow the wiring from this switch, as the connections into a diode trio (one wire from the "thermo sw") and the ignition switch aren't labeled (the other wire from the "thermo sw"). The actual solenoid on the carburetor float bowl bottom has two leads, one going to the same diode trio (not the same wire, though), and the other going to a fused battery + terminal. I suspect that the solenoid is shutting off gas in the carburetor, but without an adequate schematic, I don't see how this mechanism works. In fact, I haven't even yet found the "thermo sw", but that's from not having traced out the wiring but not seeing anything looking like what I think it might look like mounted on the engine. The schematic shows no direct connection between the "thermo sw" and the carburetor solenoid, except as it might occur by a connection inside the diode trio (not shown on schematic).
So I would appreciate any help that one might offer, including knowledge of how these two devices normally operate. One thing in particular I'd like to know is whether the carb solenoid turns the fuel ON or OFF when electricity is applied.