I've had more issues with this one B&S engine (mostly carb) than a lifetime of Tecumseh.
Engine starts and runs. Some hunting but I think a new governor spring will help that and/or futzing with that fine spring that is wrapped around the linkage wire which I guess takes up any tiny amount of play.
But it stops after about 3 minutes. Can restart easily but stops again a few minutes later each time.
Assuming it's not a mysterious ignition failure, it's being starved for fuel. But why? It's not actual flow of fuel...disconnecting the hose, it runs out fine. I previously thought it was the fact that I cannot see how air can get into the fuel tank and was considering making a pinhole but running the engine with the tank moved away a bit so the cap can be left off entirely (@ normal height) produced the same cuttoffs so it's not that.
I did get a carb kit a few years back and replaced the various parts. I've always had issues of seepage where the bowl fits together and I've always made sure the surfaces were polished clean, used a new gasket, gasket plus Permatex, or Permatex alone. Someone suggested that the fuel level in the bowl was simply too high so on the last go-round I bent the tab on the float to shut the valve sooner. So that is one possibility-- that the flow is less than consumption and it just runs out of gas until the bowl is replenished.
Another thought is whether there is some sort of air vent into the bowl that is clogged. It's true that I don't totally understand the various passages in this carb. Like on the underside, near the intake, there is an opening that is filled with copper-colored metal granuals, sort of like some auto fuel filters. I don't know if that requires cleaning.
My most recent assembly of the bowl involved 2-part epoxy so it will be a bear to open and clean that off but at least there's no more seepage. If I do go back in and apparently I must, I'd like to make it count.