Had my kid drop some fuel down the carb then I turned it over, it promptly started, died, then caught fire.

The expression on his face was priceless followed by a mad dash for a clean rag to cover it while I shook my head at him.
To quote Mrs. Slocum, it must just be
magic around your house......
Sure sounds like its out of gas. You may have bent the pickup tube so that its not as deep in the gas as it used to be.
Not sure what the air trick will do. The tank is vented, but I'm not sure to where in 74.
Later ones, you would probably blow the charcoal canister off the front, but maybe not on this one.
Might be better to blow back though the fuel line towards the tank with the cap off. You should be able to hear the bubbling in the tank if the pickup is under the gas level.
Be warned though. I watched this done on a route truck at our plant many years ago. There was a piece of plastic that someone had shoved into the tank, and it would randomly block the gas flow.
The mechanic decided to see if it was something blocking the line, so he hooked air to the fuel line with the cap off.
Tank was almost full, and a huge stream of gas shot out the filler hole.
Unfortunately, the plastic did not come out, so he wound up dropping the tank, draining it, and finally spotting the plastic.
I had nothing to do with that, but I noted it for future use.
Of course, I have
never had an occasion to use it against people who tick me off since...............