Engine runs rough and almost dies under load

Dennis(IA) · Sep 16, 2022

My neighbor has a Ford 601 workmaster , and when he mows ( 3 point mower)
and after it warms up it runs terrible. It cuts out and misses, points and plugs are not new but in good shape. I just noticed his new plug wires, they are the resistance type (not copper wires). I seem to remember that maybe the point system should have copper wire spark plug wires and not the resistance wires. Is this true or am I imagining again?

Dennis

Steve@Advance · Sep 16, 2022

It should run on resistor wires IF they are good. Cheap carbon wires don't last long. Good spiral core wires are the best choice.

Check the spark quality at the plug end of each wire when it is warmed up and causing the problem. With it running pull one wire at a time, it should give at least a 1/4 inch spark to ground.

Check the distributor shaft for side play. The points will not stay set if there is wear.

The coil could be failing or the wrong coil or coil/resistor. When it is up to temp, feel the coil, it should not be too hot to hold, or considerably hotter than the surrounding components.

There could also be a fuel delivery problem. Try loosening the gas cap. Do a fuel test at the carb. Remove the drain plug from the carb bowl, catch the flow in a clean glass. It should flow a stream, not slow to a drip or stop flowing. Look at the fuel caught, check for dirt, rust, water. Whatever is in the glass is in the tank and carb. Contamination will be an ongoing problem until it is cleaned up.

Dennis(IA) · Sep 16, 2022

Thanks Steve for the reminder of things to look for.

Russ from MN · Sep 16, 2022

I didn't see anyone else mention the condenser, try a different one, not new, but a known good one out of an engine that runs well. I have had these symptoms from a bad condenser.

Geo-TH,In · Sep 16, 2022

My Jubilee was running like carp.
New points and condenser fixed my problem.

rrlund · Sep 16, 2022

Steel or copper core wires and open the points up a little more.

jimlll · Sep 16, 2022

I had a mechanic friend working on a similar problem.
He discovered loose intake manifold/head.

Liquid_wrench · Sep 16, 2022

x2 for the condenser.

Dennis(IA) · Sep 17, 2022

Turned out to be points, did one thing at a time and points fixed it. I also had to lower the floats ( a little tab on the float arms) and add more gas to the tank. When I first checked the carb the needle would not drop down to let gas in. I thought about manifold gasket but it idled like a champ.
Thanks for all the replys.
Dennis

Engine runs rough and almost dies under load

Dennis(IA)

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Steve@Advance

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Dennis(IA)

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Russ from MN

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Geo-TH,In

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rrlund

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jimlll

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Liquid_wrench

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Dennis(IA)

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