# Farmall 140 starting troubles



## Noah12343 (Oct 10, 2014)

I have a farmall high crop 140.
We never really use it any more and it only gets moved twice a year, one in the winter and beginning of spring.
We never started it with a battery we just pop started it. And one day I pulled it out to pop start it and the darn thing would just sit there and turnover. 
So I finnaly got a battery for it and a new starter button and now it cranks and fires.
But here is the weird part. The only time it fires is when the starter button is in.
Doesn't try any other time. I don't understand what to do and have never heard of this.
If any one can help me I would highly appreciate it.


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## Country Boy (Mar 18, 2010)

First question, is the gas fresh? If it sits a lot, the gas is probably stale. I've seen units at work not start, but if you drain the fuel and refill fresh, they pop right off.

Is that a battery coil ignition on that unit? I'm assuming so by the age of the unit. If so, you really need a decent battery in the system to make it fire correctly. The generator doesn't really produce enough energy at cranking speeds to power the coil. Since you have a new battery in there, that shouldn't be the issue. When you say starter switch, is it a key switch or a push button? My 350 Utility has a key that you turn on to power the dash, ignition, and starter circuit, then a rubber button you press to crank the starter. My H has a magneto kill switch you pull out and then a large metal button you push to start it (there's no starter solenoid in the system). The 574 has just a key you turn to crank the unit. I am not familiar with the 140's to know which system they had. The Cubs that they replaced would have had the system like my Farmall H with the large metal button, but I'm not sure if they carried that over to the 140. If you could let me know, I can try to help you sort it out. There really isn't that complicated of a wiring system on that unit.


EDIT: I did a bit of research on that unit looking for a wiring diagram, and found that they used Magneto ignition and Battery ignition. I'll need to know which you have. The battery coil is a round cylinder with a spark plug type lead on it and two other screw terminals with smaller wires attached. The magneto coil is usually a box on top of the magneto assembly and has only the main spark plug like wire on it. Also, is it a 6 or 12 volt system?

They built that tractor from 1958 to 1979, so there may be considerable changes over the years.


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## Noah12343 (Oct 10, 2014)

The system is a 12 volt , it has a turn key to enable the dash then you push a button in to start it. It has a battery coil and the gas is fresh. I am starting to think it might be the coil cause everything else on the tractor looks ok.


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## Country Boy (Mar 18, 2010)

When you turn the key to the on position, do you have 12 volts to the + terminal on the ignition coil? You should, and if you don't then I'd suspect a wiring issue. The starter button puts power to the starter relay on the starter to make it activate and crank over. Some ignition systems have a second wire to the ignition coil to increase the voltage to the coil during cranking. It could be that there is a wire to your coil from the button switch that is supplying power to the coil only when cranking, and the main lead from the key switch is not connected anymore. Have you checked the wires at the key switch? I'd trace the wire from there to the ignition coil and make sure it is still connected everywhere and not shorted or mouse chewed somewhere.

If you have a test light or multimeter (better option), see if you have power to the + terminal on the ignition coil when the key is turned on, and then when the starter button is pressed. If there is no voltage with the key on, then the wire from there to the key isn't connected or the key switch is bad. Check that and let me know what you find.


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