hydro-lock in a Kohler

Danl99

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Diagnosis - broken compression relief valve and damaged camshaft. Replaced camshaft. Evidently not a very common issue.
 

smallenginerepairs

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sounds like your exhaust valve needs adjusting. if it is closed and not opening to relieve compression pressure, it will be hard to pull. check the engine brake first. if the engine brake is working properly, take the valve cover off, remove the spark plug, turn the engine over and visually watch both valves open and close. If it is not in the valve train, while turning the engine over feel for play in the shift to rule out bearings. Have patience with the guys in this forem. They all want to help you, however some expect you to know more about troubleshooting than you do, and that comes from a lack of patience and compassion on their part ! I hope this helps you to fixing your problem, Pete's small engine repair
 

v908

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I have a Lawnboy 10730, with a Kohler XT650 engine. Five years old. Seems to have developed hydro-lock, whereby I can't pull the starting cord. I remove the spark plug, and I can pull the cord fine fine (though nothing comes out of the plug hole - I would have expected some oil to shoot out). I replace the spark plug, and I can't pull the cord again. What's the fix???
If no fluid is in the cylinder, it's not hydrolock. You need to first adjust the valves, then start troubleshooting other things.
 

Danl99

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I've got good service folks. Diagnosis reported above.
 

Johner

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Have the same problem with a 2 stroke. Determined that wear from the piston TDC is cocking the piston locking it up. Suggested fix for the 2 stroke is add a thicker gasket on the base to offset the piston in a different spot at TDC. Have not tryed it yet.
 

Johner

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I have a Lawnboy 10730, with a Kohler XT650 engine. Five years old. Seems to have developed hydro-lock, whereby I can't pull the starting cord. I remove the spark plug, and I can pull the cord fine fine (though nothing comes out of the plug hole - I would have expected some oil to shoot out). I replace the spark plug, and I can't pull the cord again. What's the fix???
Might also be something wrong with the pull cord , I know sounds crazy.
 

Danl99

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Geez, guys. I TOLD you what happened. MOWER FIXED. CASE CLOSED.
 

crazy charlie

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Charlie, I once had hydro lock on my Troy-Bilt tractor from gasoline. I could not get the seat for the needle valve out to replace it so just installed a valve between the gas tank and carb. Have not had a problem since and the engine does not seem to use more gasoline than it did before.
The Kohler website pictures of the XT650 appear to show a fuel hose from the tank to the carb. There might be a way to install a valve in it to verify that it is not a leaking needle valve. Although I would think that unlikely since the OP said he was unable to restart the engine after it ran for 15 minutes.
Is it even worth fixing with an internal issue like crank bearings, etc?
I think I will install a valve for shutoff.Especially since my mower is now doing exact same thing a season and a half later after
new carb install.Got a semi hydrolock the other day with 2-3 times tried starting and just a click, then it cranked and started and blew smoke for 30 seconds just as it did last year.Fuel tank was 99% empty so it had been dripping for a few weeks .Charlie
 

slomo

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I do aerospace engineering, not gas engine engineering. That's why I'm here, because I don't know how everything about how to troubleshoot a gas engine and I thought I might get some help. I haven't really heard any good explanations for my problem, though. I'll head over to a different forum, and likely just bring the thing in for repair.
Really guy, you need more knowledge before trying to work on this. If you can't fix a Briggs single, you need more library time.

If you think another forum is your fix, think again. Here, you have access to some of THE BEST mower repair guys on the internet. It's hard for us to help you when you don't know what we are telling you to fix or look at. The guys helping you are TOP SHELF, end of message.
 
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