hydro-lock in a Kohler

[StarTech]

You got to understand you are going from no compression load with the plug out to a compression load with the plug in. This changes to whole dramatics of the rotating engine components. I have even seen recoil starter to jam because compression load. If you have worn crankshaft bearings the crankshaft can shift position under compression load.

Since this is a 21" walk behind install the plug (leave plug wire off to prevent accidental starting) and try rotating the engine with the engine brake off with the cutting blade.

 

[Danl99]

When this first happened, I assumed there was a jam at the blade, so I turned the mower on its side, saw there was no jam, and rotated the blade by hand. The blade rotated just fine.

 

[Bertrrr]

Stick a straight rod like a coat hanger or welding rod through the plug hole and feel where the piston is , if you can roll the flywheel while doing it you can watch the piston position by seeing the rod go up and down

 

[Danl99]

Does not sound hydrolock as the term indicates there must be a liquid involved. It more likely a mechanical failure such as the ignition being loose, engine brake not releasing, or internal problem.

BTW BDC is Bottom Dead Center and TDC is Top Dead Center. Both refers to the piston position.

As for the rod you would inserting it thru the plug hole to find where the piston is sitting in the cylinder.

Note sure if this info is useful, but right now, with the motor "stuck", I remove the spark plug, and the rod, when inserted reaches 2.0 inches below the plug seat. I suppose I could jostle it a bit, and get the motor started, and then try it again after that. Do I roll the flywheel by rotating the blade?

Stick a straight rod like a coat hanger or welding rod through the plug hole and feel where the piston is , if you can roll the flywheel while doing it you can watch the piston position by seeing the rod go up and down

 

[StarTech]

Can't sit here over the net and hold your hand. You got know to work on an engine before we can help you. There basic things that you must know first and it appears that you have no idea of what you are doing.

 

[Danl99]

OK, sounds like we're done. I was hoping for some useful advice here. Ther seems to be some reluctance to giving that.

 

[StarTech]

No, the problem is that you are posting as if you don't have foggiest idea of how to troubleshoot an engine.

It kinda makes sense that would be something loose if you are able to get it to turn over by jostling it don't it? We can't see what is going on on your end.

 

[Danl99]

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.

 

[StarTech]

Well the troubleshooting very similar to gasoline 4 cylinder horizontal opposed Piper Tomahawk engine mechanical wise...except it a much larger engine. When things comes loose they tend to bind things up. Just don't want it happening at 5,000 ft but does sometimes. My engine once started missing like mad at 4,000 ft over a major city with no place to land. That when it get very scary. At lease I had a 16:1 glide ratio and I made to the local jetplex for an emergency landing. I was already down to below Angles 1 and the local elevation is 630 ASL. Not a lot left to spare.

But I would recommend you do take the engine into small engine repair shop.

 

[ILENGINE]

I am just thinking out side the box. But maybe a cause of a bad bearing on crankshaft that is allowing the crankshaft to tilt in a bearing and allowing the flywheel or something else to bind on something else which won't be noticeable with the plug in but would be under compression.

Had a Honda GC160 a few years ago where the top bearing failed allowing the flywheel to hit the ignition module. Currently have a Vanguard 31 hp in the shop that has a bad crankshaft bearing allowing the flywheel to jam on the ignition modules