Farmall M serious problem

I have a 46 farmall m that i pull with in antique pulls and the other day i was backing to the boat and the tractor started to die like it wasnt getting fuel so it shut off. the gas was on it was getting fuel. we pop started it checked the points and opened a screw on the carb a bunch of gas came pouring out. what is causing the problem shutting off? i have a magneto but it is canceled out with a coil and an external condenser. i have a 12 volt battery but i am only charging at 6 volts with a generator. it also sputters at times when reved up.

First suspects - the coil and/or the condenser. Second suspects - the ignition switch or the points gap.
See if you can get it to die again. Then immediately check to see if you have spark. If you do, then it is the third suspect - fuel system. mike

Charging at 6v will not actually put a charge in a 12 V battery. Disconnect the generator and run only the battery. Make sure the battery is fully charged before each evening, and all will be well. JimN

Assuming its an ignition problem and not a fuel problem, there are a couple things to check. First, are you using a 12volt coil or a six volt coil with a ballast resistor? If you have a 12 volt battery running a six volt coil with no ballast resistor, you'll have twice as much current going through the points and they'll burn up in short order. I'm not sure how much current magneto points are intended to carry, but I suspect its a lot less than a set of distributor points.

Check the points, make sure they're not burned and are gapped correctly. The idea of checking to see if you have spark immediately after it dies is a good thing to do, it'll tell you if the engine died because of a heat related spark problem or if there's something else wrong. Also check to make sure that there isn't a broken or loose wire somewhere in the ignition circuit. I'd carefully check the wire going from the coil to the points, particularly where it goes through the magneto shell.

The fact that you have fuel to the carburetor doesn't mean you don't have some other problem in the carburetor, either. Could be something as simple as a piece of crud in the main jet. If everything seems good ignition wise, and you still have spark when it dies, the next thing I would try is a carburetor overhaul.

Keith

(quoted from post at 17:17:30 08/18/08) Charging at 6v will not actually put a charge in a 12 V battery. Disconnect the generator and run only the battery. Make sure the battery is fully charged before each evening, and all will be well. JimN

Click to expand...

Good point, Jim. I overlooked that. mike

Your battery is probably low on charge. Hal

If your using a resistor with an internal resistor coil you will get a weak spark.