Runs Rough and Dies

koehleraj67 · Apr 13, 2014

I have a 36 F12 that when the engine is gets nice and hot it starts to runs rough and eventually dies. I can get it started again but it will still run rough and die shortly later. I think it might be a condenser going but am at a loss. The plug wires are good and the timing is spot on. Someone tried telling me that it could be carb or fuel pump problems but I don't think that sounds right.

Michael Soldan · Apr 13, 2014

Your symptoms make me think coil. We used to pour cold water over a coil if the engine stopped..if it fired right up we knew it was the coil.

Dave Allgire · Apr 13, 2014

I think your idea of the condenser going bad is a good one. I know you have to remove the mag to replace it, but it's cheap insurance. When is the last time you applied a few drops of oil on the impulse mechanism? Just a thought, maybe its drying out when it gets warm.

rustyfarmall · Apr 13, 2014

(quoted from post at 06:44:46 04/13/14) I have a 36 F12 that when the engine is gets nice and hot it starts to runs rough and eventually dies. I can get it started again but it will still run rough and die shortly later. I think it might be a condenser going but am at a loss. The plug wires are good and the timing is spot on. Someone tried telling me that it could be carb or fuel pump problems but I don't think that sounds right.

It's a magneto ignition, so yes. the problem might be the coil, but very unlikely. I think you need to pull the rocker cover and check the clearance on the valves. Everything expands when it gets hot, and the valve clearance gap is probably just closing up completely, which means the valves can no longer fully close. If the valves cannot close, the engine will run very poorly, or not at all.

David G · Apr 13, 2014

I would doubt that valves too close would cause it to die, would think a bad coil was more of a probability.

I did get rid of the high speed flutter on my Farmall by checking the valve clearances. It only takes a couple of thousands off.

michaelr · Apr 13, 2014

My F20 does the same thing. Coil gets too hot. We stop and let it cool down for 15 minutes, then it will start again.

SadFarmall · Apr 14, 2014

Good idea to be sure the impulse mechanism is oiled, though it should not trip when the engine is running. If it does the engine idles too slowly or there is a mechanical upset in the magneto.
SadFarmall

rustyfarmall · Apr 14, 2014

(quoted from post at 10:56:22 04/13/14) I would doubt that valves too close would cause it to die, would think a bad coil was more of a probability.

I did get rid of the high speed flutter on my Farmall by checking the valve clearances. It only takes a couple of thousands off.

Really?? I already explained just how such a thing can happen. It is one of the more simple laws of physics.

Runs Rough and Dies

koehleraj67

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Michael Soldan

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Dave Allgire

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rustyfarmall

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David G

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michaelr

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SadFarmall

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rustyfarmall

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