Solved: Confused - 1F running rough (and sometimes not at all)

[Rocky_LC]

When the thing stops, go to your fuel tank and open the cap. If you hear a big sucking sound, you’re pulling a vacuum in the gas tank and you’re fuel system vent Ian working properly.

 

[samatulich]

I had a similar issue with intermittent power loss. Replaced the fuel pump and it has run just fine for a few years now.

 

[Fj40owen]

Thanks all, problem solved.
Turned out that the baffle in the exhaust manifold was stuck mostly closed.
Glad it wasnt a bigger deal, and at least it got a tune up in the process.