Stuck valves

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Dirty Mike
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Joined: Thu May 07, 2015 11:16 am
Zip Code: 76108
Tractors Owned: 1951 farmall cub

Stuck valves

Postby Dirty Mike » Mon May 09, 2016 10:50 am

How to fix stuck valves without tearing the motor down? It has been sitting for a few years.

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Re: Stuck valves

Postby Eugene » Mon May 09, 2016 11:10 am

Hood off. Remove the spark plugs, squirt solvent into the valve(s) area. If the valve is open, try to get the solvent under the valve and on the valve stem.

Remove the valve cover. Squirt solvent on each valve stem. Wait a bit, the squirt again. Rotate the engine. Might want to try the solvent through the spark plug holes and on the valve stems for several days.

Roll the engine over by hand. Observe which valve are not closing. Usually stuck open.

If you can observe the edge of the stuck open valve, hard wood dowel, gently tap the valve down. Solvent. Rotate the engine observing valve action.

Another trick after the solvent soak. Place a .030" feeler gauge between the tappet and valve stem. Rotate the engine to lift the valve. Solvent, tap valve down.

If the above doesn't work you can remove the manifold and solvent soak the valve stems.

Edit. If the engine is stuck, probably better to remove from tractor and disassemble.
I have an excuse. CRS.

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Re: Stuck valves

Postby staninlowerAL » Mon May 09, 2016 2:02 pm

If you determine which ones are open and will not move, you can use a needle nose vice grip pliers and hold the stem below the keeper, spray and wiggle the valve slightly. The spring should provide enough force to make it move closed. Keep repeating as Eugene said, tapping lightly through the spark plug hole. It might take a little while to free them up. The last one I had like this had been sitting without moving the engine for 30+ years. Stan

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