Cub with a stuck valve...really stuck

redtom · Jun 8, 2013

My dad parked his lowboy cub about 10 yrs ago in his shop and it sat. Finally got time in my life to get it out. Dry shop, never got water in it. Two hard spots when I cranked it, but not too hard. Finally got her running on three cyls. and let it warm up. Thought the valve would free up when it got warm. Nope. Pulled side cover and one valve is stuck up pryed it down a few times but it is tighttt. If that valve was rusted in the closed position, do you think the tappet would bend the valve stem? I'm gonna pull the head anyhow. But I've not seen a flat head bend a valve.

ben there · Jun 8, 2013

i doubt it bent valve stem...carb cleaner on the junction of guide and stem is what i use to free stuck valves up...should be able to see from manifold ports.

screwstick · Jun 8, 2013

As Ben said, I doubt it bent the stem.
If you can pry the valve down, keep spraying with penetrant and moving it up and down. It'll free up eventually without pulling the head. It may not seal real well, but it should free up.
Did you have to re-prime the oil pump?

36 Coupe · Jun 9, 2013

Its time to buy a can of Kroil.Take the manifold off and spray under the valve head and leave it alone for a while.If you are too tight to buy a can of Kroil heat the valve, then apply some parafine from a small candle to the stem.

old · Jun 9, 2013

Should have filled the cylinder with ATF before you even tried to turn it over the first time. Any time you get a machine that has sat a long time it is a good idea to do an ATF treatment at least 24 hours before you try to spin it over. Me I would fill the cylinder yet all 4 and let it sit that way a couple days. And on that stuck valve get ATF on as much of it as you can

Cub with a stuck valve...really stuck

redtom

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ben there

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screwstick

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36 Coupe

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old

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