Farmall Cub

Hey all. I'm fighting an issue with my IH 424 (gas version), and need some advice.

After about 2 hours, under a load (usually going up a hill) the tractor will die. I can restart it, and it'll run for 20-30 seconds, then die again. Pulling out the choke knob causes it to run a little longer. Once on level ground, it'll run pretty well. Fuel pump was replaced last year, and I can hear it running while the problem happens. The fact that the choke affects the problem makes me think it's fuel related, and since the fuel pump is running I believe it's good. That leaves the carb, but I don't understand why it would take a couple of hours for the problem to happen. I can leave the tractor alone once it happens for an hour or two, then when I go back to it it'll run fine for a couple of hours.

Any ideas would be appreciated.

It sounds more like a bad ignition coil. When the windings inside start to brake down (usually due to vibration) the resistance in the coil rises. After a certain amount of use the internal temperature of the coil rises and causes more resistance - then it stops working. After it cools and the resistance drops - then it will run again until it gets hot. Cheap enough part to just replace, but also replace the ignition points and condenser while you are at it. Plugs, cap, rotor and wires might also be a good idea if they are old.

One other very slight possibility might be a blocked gas cap vent hole. when it starts to loose power, just loosen cap to see if problem goes away.

Trouble shooting is over half the battle.

Good luck, NJDale

First thought - happens when going up hill. Trash partially blocking the fuel inlet inside the fuel tank. Fuel flow problem.

Coil might also be partially mal-functioning. - Along with a fuel flow problem.

Coil, cap, rotor, and points were replaced about 6 months ago. I have another coil around here somewhere, it wouldn't hurt to stick it on and try it though. Fuel tank and lines are clean, loosening the gas cap has no effect on it. I've been fighting with it for a few months now, and it's just getting frustrating.

Next time that it happens, remove air intake from carburetor and feed it some spray hydro carbons (like WD40 or something) to see if it is a fuel problem. Then go from there with the diagnosis. NJDale

Another thought. If it's not the coil. Check the carburetor float; for height, drop, binding.

Since use of the choke seems to lengthen the run time - would indicate a fuel related problem.