A long time ago, someone, probably my dad, told me that "80% of all carburetion problem are really electrical." In other words, your engine doesn't run, and you suspect a fuel or carburetor problem, when all the time it was an ignition problem.

This happened to me over the last week, when my tractor (a Ford 640) would not start. I wasn't the one operating it, and the issue became confused because he didn't use the fuel shut-off, so we really did have a carburetion problem -- the carburetor was flooded.

I messed around with various stupid and irrelevant actions until I finally woke up and brought a voltmeter into play. I discovered that the ignition fuse had voltage at both ends, but the fuse HOLDER had no voltage at the far end. It had corroded and wasn't making a good connection. I burnished this up a bit, the voltage magically appeared, and the tractor started right up.

This, by the way, is what you get when you use inferior parts. When I converted the tractor from 6V to 12V operation, I added an el cheapo fuse block. I should have bought a marine-quality one. Never again!

Another take-away is that, if you allow things to go downhill, it's hard to tell what's going on. I was down to one working headlamp, and then zero. With working headlights, I can use the lights as an impromptu voltmeter, because the way things are wired, the ignition is getting voltage if the lights are. But with both of them burned out, I had to go find my multimeter. Life is simpler if only one thing is broken at a time!

Nevertheless, I designed a T-shirt this morning, commemorating old iron, which you can see below. After all, my tractor is older than I am!