Trouble; Is There Trouble?

I heard this Fairmont start up while I was a few displays away, but it quit before I could get over to it.  The owner of this engine display was looking for parts when I showed up.  A 1/4" nut had come loose from the top of the intake assembly, and parts had gone flying.  He found the cover and the check valve, but he had to rob a nut from another engine, and the spring that goes behind the check was nowhere to be seen.  He made a bold effort, but the little Putt-Putt engine couldn't be made to run without a properly functioning carburetor.  No worries, though.  He said he has plenty of spare parts at home.