This is a 1975 Ford F-350. It has been sitting idle for 6 months, and is rarely used.
Normally, when I try to start it after sitting for a long time, it takes a bit of cranking before it starts. I assume this means the fuel in the fuel line and carburetor float bowls evaporates, and has to be replenished.
This time, it wouldn't start despite extended cranking.
I manually added a teaspoon of fuel directly to the carburetor, cranked the engine, and it ran for a few seconds. So I knew that compression, timing, and spark were OK, and that it was a fuel issue.
I disconnected the fuel line from the carburetor. The end of the fuel line, and the brass fitting it connected to, were both glistening, suggesting there was moisture. I put the fuel line in a can, cranked the engine, and saw fuel squirt out.
I reconnected the fuel line, and poured a little more fuel in to the carburetor. Cranked the engine, and it started up and ran fine.
What happened? What changed when I disconnected & reconnected the fuel line?