Halfway thru the four days of no electricity snowmageddon brought me I remembered I had a generator, yeah I know, lol. I pulled it out of storage and went to fill the tank. the tank was rusty. Mid you I had only ever fired it up once, about three years earlier, right after I bought it, drained the tank and put it in storage.
So I fabbed up a temp tank, used a two gallon plastic tank I had, drilled a hole in a bottom corner to screw in a barbed hose fitting and plumbed it to the carb. Bungee corded it to the top of the original tank and filled it up, put the cap on and ran it. No issues, I think the cap self vented, or at least allowed air into the can in a vacuum situation, in any case it needed the cap on otherwise it would splash gas out the opening. Ran just fine.
Not sure I'd use something like that on the road, for a static test run, yes.