Ym1500 head gasket leak

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Hnewman144
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Ym1500 head gasket leak

Postby Hnewman144 » Tue Apr 03, 2018 6:59 pm

So I rebuilt the engine in my Ym1500 and it has been purring like a kitten. Have sense put about 10 hours on and I noticed today the outter three studs were a little wet. Took a closer look and one of the studs had tiny bubbles blowing up around the threads of the head stud. So the head gasket is obviously leaking. But I don't understand how, I cleaned the mating surfaces really good, had the head worked and cleaned. Torqued to right spec's in increments. And even followed Hoyes advice and ran a hot cold cycle and re torqued. I noticed they were just a little wet after last use but thought it's was my valve cover gasket leaking over on to the studs then today I saw the tiny bubbles and seen there was pressure. Any one ever had this happen?

winston
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Re: Ym1500 head gasket leak

Postby winston » Wed Apr 04, 2018 4:38 am

Don't guess it has been running hot?

Hnewman144
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Re: Ym1500 head gasket leak

Postby Hnewman144 » Wed Apr 04, 2018 4:56 am

Not at all. Running around 180

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Re: Ym1500 head gasket leak

Postby Hnewman144 » Wed Apr 04, 2018 7:18 am

I haven't noticed an coolant loss. But it is very small leak. I can't wrap my head around how it's coming up the stud threads on all three studs on the outside of the valve cover. No other leaks on the outside of the block. Just the studs. I think my oil is overfilling a bit to. And if so then I assume the other three studs that are under the valve cover are leaking water into the oil.

winston
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Re: Ym1500 head gasket leak

Postby winston » Wed Apr 04, 2018 8:24 am

Wish I had an answer for you. Very unusual to leak around one stud, much less several.

Norm
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Re: Ym1500 head gasket leak

Postby Norm » Wed Apr 04, 2018 9:10 am

Do those studs screw into open water passages and need to be sealed?

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Re: Ym1500 head gasket leak

Postby Hnewman144 » Wed Apr 04, 2018 9:22 am

Norm, my point exactly. They don't screw into water ports at all. The head gasket has it's own holes cut out for the studs. The stud holes and the water passage holes are completely separate.

Norm
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Re: Ym1500 head gasket leak

Postby Norm » Wed Apr 04, 2018 9:33 am

Not referring to water passage holes. Unless someone knows for sure you would have to unscrew the studs and see if they screw directly into open water passages., otherwise check head for trueness, (probably .003) possibly have milled and replace gasket .

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Re: Ym1500 head gasket leak

Postby Aaron » Wed Apr 04, 2018 10:02 am

Are the head nuts loose? What happens if you re-torque them? I can't remember ever hearing about compression or oil coming out around the head studs.

Hnewman144
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Re: Ym1500 head gasket leak

Postby Hnewman144 » Wed Apr 04, 2018 10:20 am

I haven't tried tightening yet. But im pretty sure it's coolant and not oil. And there's no compression coming out around the studs it's just when the cooling system heats up to operating temps the pressure of the cooling system is some how force the water up the threads of the studs. It's barely any but not supposed to be any at all. The three studs on the inside may possibly be doing the same thing. And if so then there's water getting into oil. Was I supposed to pull the studs and pipe dope them back into the block or something? Never seen this before

PaulW
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Re: Ym1500 head gasket leak

Postby PaulW » Thu Apr 05, 2018 3:55 am

Maybe it's just some old coolant in the bottom of the bolt holes trying to escape when it warms up?
Paul W YM1500 & YM14 MkII

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Re: Ym1500 head gasket leak

Postby Hnewman144 » Thu Apr 05, 2018 8:49 am

Paul I hope your right. Wish I new how to tell for sure.

Norm
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Re: Ym1500 head gasket leak

Postby Norm » Thu Apr 05, 2018 9:17 am

"Was I supposed to pull the studs and pipe dope them back into the block or something?"
I would have, if any possibility of a leak. A lot of engines are built that way.

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Re: Ym1500 head gasket leak

Postby Aaron » Thu Apr 05, 2018 9:36 am

I looked at a few blocks that we have in the warehouse and the stud holes appear to be closed. None of them appeared to go into any water or oil ports.

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Re: Ym1500 head gasket leak

Postby Hnewman144 » Thu Apr 05, 2018 10:53 am

I find it very weird that the only head gasket leak I have is coming up the stud threads. There to many possibilities for leaks. It's not burning water. It's not leaking where the head and block meet. It would be really strange if the gasket is blown between the stud hole and a water holevon every stud. I don't think that's just a coincidence. Seems to me something has to be off somewhere. The head was decked, I torqued with a freshly calibrated snap on torque wrench to the right torque spec's. How could it only be leaking up through the studs but no where else? Nubbin suggested they may be stretched? But if that were the case it seems like it would not only be coming up the studs , but entering the cylinders, the oil, and every other place.


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