Farmall 400 backfiring and dying

My 130, same distributor and drive gears stripped back two months ago. Acted very much like yours except it was over much quicker. Just as this started did you notice the tractor laboring as if timing advance was off by a few degrees.

This messes them up quite badly, usually the first sign is tractor laboring, then it starts popping and belches black smoke. Even when it get so far off on timing advance that it ocasionally backfires, it may still start and run for a bit. Finally it will backfire as you turn it over on starter and the backfire will almost deafen you, but at that point it probably wont make any attempt to fire and run.

I had this happen to my 130 tractor twice, first about 1994 and again just two months ago. First time gears were worn badly. This time I found crushed ice all through the grease in the gear box. I suspect there was a pocket of water in the grease that froze to a cube, it was about 0 degrees F. I had been plowing snow for about 1/2 hour from cold start up, and from the looks of the gears I think I started off with a block of ice in there and those gears ground it up. Also there is a bushing around the shaft on the driver gear. I didn't replace that bushing in 94, I think maybe I should have. I can see where gears have been riding each other, thus I don't believe ice was the complete factor. The gears were not worn near as bad this time as in 94, but they did have a lot of fresh damage, caused by the ice in my opinion.

my 400 did that very same thing. found out the wiring that some one else did was wrong. Had the switch and the resistor wired wrong and the resistor was shot. New wires and resistor and hasn't quit yet. the points finally went out this week after 6 years of running.

Let me know how it turns out.

• Hobby farm

• Hobby farm

If the choke thing doesn't help most likely the coil is failing. It works OK cold, but as it heats up it's output voltage tails off, causing the engine to first misfire and then quit altogether.

Try running it again. When it falters immediately shut it down. Now pull the center wire from the distributor and attach it to a good spark. Lay the plug on top of the distbutor and crank the engine with ignition switch "on". You should see a hot, blue spark at the plug. However if the spark's a lazy yellow, suspect a bad coil.

Also check the coil temperature by hand after it's been running a few minutes . If it's noticably warm to the touch it's probably the old 6 volt coil and you are now feeding directly from it 12 volts. You need to add a ballast resistor in the primary circuit to knock the voltage down to 6 volts to keep it from overheating (and also keep the points from burning out prematurely)

----

Incidentally from your description it sounds like your ammeter is wired up wrong. Turning on the lights should not change the ammeter reading or only cause it to indicate LESS charge.

Try turning on the lights the the engine stopped. A correctly wire ammeter will show 5 - 10 amps of DISCHARGE with the lights on.

But the ammeter acting funny could point to a bad or improperly installed voltage regulator. Problems like that are why I don't do voltage conversions.