Farmall Cub engine noise

Anonymous-0 · Jul 20, 2012

I just bought a 51 cub. Engine makes a tap or knock when not under load. When pull on engine it does not make a sound. Runs smooth and starts fine. Any ideas?

rustcollector · Jul 20, 2012

Could be as simple as a valve needing adjustment to carbon buildup on a piston to worse a rod bearing.

Janicholson · Jul 21, 2012

Listen to the noise at idle, go to the carb side and move the governor to carb rod a little, (enough to make it change speeds a fer hundred RPM, not much. Listen to that knock, if it changes or goes away irregularly, and then comes back, it could be a wrist pin. I would not worry about wrist pin noise, engines can live for many years with a noisy wrist pin. If the noise stays consistant, and seems deep in the engine, Living with it might be OK. Keep tabs on the oil pressure, If the needle fluctuates radically at idle, I would probably remove the pan and check bearing clearances. If the pressure is OK, just keep an ear to the noise, and if it progersses, or changes, I would suggest a teardown sooner than later, as expenses mount as connecting rods find daylight. Jim

jbp · Jul 21, 2012

Silly as it sounds, a loose fan belt can cause an engine knock, but only at a certain speed. At just the right speed the belt will whip and make a very bad knocking sound. Had that to happen on my dads 53 Cub. Joe

Farmall Cub engine noise

Anonymous-0

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rustcollector

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Janicholson

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jbp

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