valve sticking on cub

bv · Jul 16, 2013

is there any trick to cure a sticking valve on a cub engine without pulling the head?

old · Jul 16, 2013

Couple things you can try that may help. #1 fill the cylinder with ATF and let sit a few days. Spin it over with the plugs out to clear the ATF out of the engine and run it. #2 run 1qt of ATF in 3gal of gas. The ATF cleans carbon off the valves and also lubes them

El Toro · Jul 16, 2013

If what Old suggested doesn't free the valve I would pull the head. Pull the side cover on the engine block and squirt engine oil around the valve stems. Tap the open valve lightly with the wooden handle of a hammer to close it. Bump the engine over to see if the valve keeps closing.
Hal

Dalex · Jul 16, 2013

I just did one a few weeks ago that was really stuck. We pulled the gas tank and removed the spark plugs .then we poured some ATF in each cyl and then using a thin screwdriver through the plug holes , we tapped the valves down that were stuck in the up position .We had to do this many times as they were hard to loosen up.We kept tapping and cranking until compression returned to each cyl , then with a fresh set of plugs , it fired up ! Good luck on yours !

valve sticking on cub

bv

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old

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El Toro

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Dalex

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