Kohler K321AS Oil Leak

[DaveLinCT 3]

The 14hp Kohler K321AS engine on a Wheel Horse C-141 recently developed an oil leak. The leak is coming from a loose, stripped or broken bolt (pin) near the governor linkage. Oil blows out past the bolt. The bolt doesn't fall out because the governor linkage blocks it from falling. I can't tighten it.

The bolt has a Philips head and what looks like a copper washer. I believe it's #4 Pin on the exploded governor parts diagram. 

What is the purpose of the pin/bolt? Assuming it's stripped, can I just purchase a new pin and washer and screw it in?

[pfrederi 17,147]

There is no seal there...If you have oil blowing out more likely your crank case breather has an issue. Make sure it is assembled correctly

 

 

[squonk 38,940]

That screw keeps the governor gear on the shaft it rides on.. If you are lucky the gear is still in position and the tab the gear activates on the shaft isn't broken. But looking at the threads on the pin, I wouldn't be surprised that the block threads are shot. 

Edited October 15, 2023 by squonk

[DaveLinCT 3]

If the threads on the block are shot is the engine toast?

The engine runs fine now. The oil blow by is not great, just messy. Do you think if I keep running it there’s a risk of internal damage? Is it something that could/would be fixed by rebuilding the engine? 

[squonk 38,940]

Have you tried to tighten the bolt? If the block threads are shot the block is toast. If you run it and that bolt backs out the governor gear can wobble on the shaft. I think the shaft the gov. arm clamps to would keep it from falling off but if it gets damaged you have to take apart the complete engine. You could try cleaning the bolt with brake cleaner and put some Loctite thread repair compound on the threads of the bolt and letting it cure.

[953 nut 51,736]

Remove the governor lever (#8) and use a slim screwdriver or icepick to push the governor gear in as far as it will go. Be sure the Stop Pin is not going to inter with the weights on the gear. You can put some LOCTITE on the threads when you tighten the pin. 

 

[Achto 26,571]

1 hour ago, squonk said:

Have you tried to tighten the bolt? If the block threads are shot the block is toast.

 

I would disagree with this statement. If the treads are stripped out, you could install a Helicoil to repair the threads. The copper washer on the bolt/pin will seal the hole when the bolt is tightened down. 

 

When you install the Helicoil, pack the drill bit & tap with grease to keep metal chips from going into the block. Make sure that you put red Loctite on the Helicoil when you install it.

 

A Helicoil and a new pin should solve the issue.

 

I believe that the threads are 1/4-20. Please double check this though.

https://www.amazon.com/Helicoil-5521-4-Coarse-Thread-Repair/dp/B0002SRE8Q/ref=asc_df_B0002SRE8Q/?tag=hyprod-20&linkCode=df0&hvadid=312192774361&hvpos=&hvnetw=g&hvrand=12777620014478720899&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019452&hvtargid=pla-570290618125&psc=1

Edited October 15, 2023 by Achto

[WHX?? 46,808]

I got a motor apart now I'll check that thread size. 

Pull the pin out and check the block threads.

22 minutes ago, Achto said:

1 hour ago, squonk said:

Have you tried to tighten the bolt? If the block threads are shot the block is toast.

 

I would disagree with this statement.

i would too... You may get blind $hithouse lucky and they are OK. You'll only need a new pin. If they are trashed ... yes helicoil. Use the greased tap method and if it helps you sleep better put a magnet by the oil drain. Ain't no way I would trash a otherwise good K block for something this minor. 

[DaveLinCT 3]

Thanks for the advice and information. Later this week I’ll see if I can get the pin to stay in with Locktight. If not new pin and helicoil. 

[tunahead72 2,342]

This may help you...

 

Kohler Governor Stop Pin -- Do I Have a Problem? - Engines - RedSquare Wheel Horse Forum

 

[squonk 38,940]

Those pins are usually pretty tight. They don't fall out for the heck of it. Unless someone has been into the engine and didn't get it tight my main concern when I said the block is toast is there may be a crack there that expands when the engine heats up. 

 

Take it apart and spray the hole and thread area with carb clean and let it air dry. If there is a crack the cleaner will make it visible. Inspect carefully with a magnifying glass.

 

There is a good chance I have a spare governor pin. I would have to go look if it ever stops raining

[WHX?? 46,808]

Sure does look like the pin threads are stripped. Maybe just the pic but the million $$ ? is how did it get stripped? Can't imagine tightened that much. 

Yep 1/4-20 threads.

Edited October 16, 2023 by WHX??

[squonk 38,940]

1 hour ago, WHX?? said:

Sure does look like the pin threads are stripped. Maybe just the pic but the million $$ ? is how did it get stripped? Can't imagine tightened that much. 

 

 

That's kinda what I've been trying to say. They don't fall out by themselves. I'm wondering if the hole is beat up and that pin is bouncing around banging the  threads. 

 

I have a spare pin if needed. 

Edited October 16, 2023 by squonk

[squonk 38,940]

I would be suspect to a crack in this area:

 

[8ntruck 6,376]

Magnaflux or dye check would be useful to check for cracks.

 

You could also try applying a penetrating oil (Marvel Mystery Oil, auto trans fluid would also work) on the block in the area circled in the picture.  Let it sit for a few minutes, then wipe the surface clean witn a rag and a quick drying solvent.  Once dry sprinkle a light coating of talcum powder on the area.  If there is a crack, the talcum powder will pull some of the oil out of the crack, making it visible.

 

This method dates back to landing gear inspection in WW 2.

[WHX?? 46,808]

21 hours ago, squonk said:

I would be suspect to a crack in this area:

 

Why is that Sqounky? Really no stress in that area. 

[kpinnc 10,746]

It's also common to have some oil leak around the valve cover. Especially if the drain by the tappets clogs up or if the breather was backwards. 

 

It wouldn't ever hurt to check the valve adjustment anyway. Just what I call an "OSI" obvious um "stuff" inspection around the valve area. 

[squonk 38,940]

4 hours ago, WHX?? said:

Why is that Sqounky? Really no stress in that area. 

Just the fact the block was molded/ machined there plus the holes being drilled and tapped. I've seen engine blocks cracked in all kinds of places for no obvious reason.

Edited October 17, 2023 by squonk

[DaveLinCT 3]

I pulled off the governor lever and removed the pin. The threads in the block look pretty well gone. That pin must have been rattling around for some time. I don’t see a crack with a magnifying glass. 
I think I’m going to purchase a new pin and the Helicore and try that. 

[squonk 38,940]

41 minutes ago, DaveLinCT said:

I pulled off the governor lever and removed the pin. The threads in the block look pretty well gone. That pin must have been rattling around for some time. I don’t see a crack with a magnifying glass. 
I think I’m going to purchase a new pin and the Helicore and try that. 

I don't think that washer is the correct one. I think it is supposed to be flat. I installed copper flat washes from McMaster Carr with no issues That may have been a cause of your problem. The small block and big block pins are the same part #. I would assume the washer is too.

[squonk 38,940]

Pin with a washer I took off a K181 and a new washer