Head or exhaust gasket

Icr242005

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Took the boat out last night, tried to use gas from last year the boat started running really bad change the tank right away made it about a quarter-mile still running crappy, change the plugs ran a little better but not 100%. Finish the night out got up this morning pulled the plugs bottom plug/cylinder was full of water, top cylinder/plug was clean and dry. Did a compression check 139/141. Pull the head off and everything looks good inside no pitting on the piston and cylinder no problems at all. Question is if it was an exhaust gasket would there be water in both cylinders or is this just a head gasket
 

jerryjerry05

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Close up pics.
Pics of the gasket? What condition?
Pics of the head?
If the gaskets gone bad?? you can usually tell.

It could be either?

They sell a bore scope for the new cameras.
I paid about 10$ has a great pic.

You can access the exhaust chest through the ports in the piston hole.
If there is water in there it will show.
 

Jiggz

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As Jerry said, you need to do a post mortem analysis of the head gasket and the condition of the head and mating surfaces. Hopefully, it's just the head gasket as this is much easier fix. If you replaced the head gasket recently, always make sure to follow correct torque pattern and at least do a two--step torquing ( 3 step is recommended). And finally, after the first couple of hours of run, you need to re-do the torque on the head in the same correct pattern.
 

Icr242005

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Does anyone have the pattern and torque spec. I have a bore scope I’m going to use tonight and look in the exhaust ports. I have ever seen the inside of a outboard motor but so I don’t know exactly what is in there. If it was leaking from the exhaust gasket wouldn’t it have water in both holes?
 

Icr242005

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BTW for some reason I can not upload pics. I’m pretty sure on the very bottom of the head gasket was a place we’re it looked like the gasket failed. Maybe I’m lucky on this one. Lol doubt it though
 

Jiggz

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Make sure the pic is resized not to exceed 500Kb(?) in size. If the leak is in the exhaust gasket, you could end up having water on both cylinders depending where the leak it. Usually, the lower cylinder gets it first though.
 

Icr242005

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So I have not cleaned anything just wiped it off with rag. I went to go get a head gasket yesterday and the parts guy come up with a different part number than I did. Could someone tell me what the correct head gasket part number is for this motor.
 

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jerryjerry05

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1989 model

I don't see any damage or obvious problem spots on the head or gasket.
Doesn't look like it has hardly any use at all??
You can try a thin coat of sillycone on the gasket, reinstall and try to see if it floods again?
If it does? then I'd check the exhaust housing.
If there's water above the level of the bottom of the block in the exhaust housing?
Then I'd guess the gasket's gone??

The gasket made a few changes over the years.
What part# did you both come up with?

F691529-1 gasket
 

Jiggz

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Absolutely agree with Jerry's recommendation. Put it back up and make sure you torque it properly. Torque to 270 in-lbs. Note INCH POUNDS! Always do at least a two step torque process (3 is recommended) meaning in this case you can first torque all bolts to 135 inch-lb and then go all over again from the starting point and final torque to 270 inch pound. And finally double check all bolts torque to 270 in-lb without moving or turning no more than an 1/8 turn. If any bolt moves more than 1/8 turn, you need to go back again from the starting point until none moves more than 1/8 turn.

Torque pattern is starting from the two middle bolts and moving out in a spiraling manner. Here's a diagram for a 125HP but the process is basically the same.
 

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Icr242005

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Thanks for the info. I’m just buying a new gasket. Something about that one I don’t like. It come off way to clean, like it almost never seated/sealed properly. I have a bore scope and will look here in a few months mins. Head gaskets are easy to replace so I will try that first and see what happens.
 

jerryjerry05

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If you don't have an inch # torque wrench??
It equals, about 18-20 ft. pounds.
Do it in 3 steps 13# 17# then 20#
Some retorque after running a while?

As clean as that gasket is? That shows it just didn't have much use.
I suggested sillycone to test.
Then use the new gasket if that works.
But there a LOT of motors running well with sillycone'd head gaskets.:)
 

Icr242005

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Never used the stuff. I see there are several different “kinds” of it. What is a good brand and should I use use the copper stuff or not. Do they recommend using it a new head gasket’s too. Thanks for the help.
 

The Force power

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Never used the stuff. I see there are several different “kinds” of it. What is a good brand and should I use use the copper stuff or not. Do they recommend using it a new head gasket’s too. Thanks for the help.

Form a gasket Silicone made by Permatex is a good product, I've used it many year while working on diesel engines
 

Jiggz

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Actually, no gasket sealant is required. But for those who wants to of course they can. The biggest source of problem when installing new gasket is:

1. Improper torque
2. Improper torque pattern
3. New gasket not properly aligned with the block and head. Note this is very critical. To ensure the head stays properly aligned tilt the motor as high as possible to its horizontal. Use temporary tape to hold it in place until you have the two middle bolts hand tightened. If you try to install the gasket with the motor in full vertical there's a very good chance it will drop about 1/16~ 1/18 inch, enough not to keep a good seal.
4. Failure to re-torque after a couple of runs. This only applies to new gasket.
 

jerryjerry05

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I use just the black, that way it doesn't show up like blue or copper does.
They all do the job.
Even the clear used in sealing windows would work.
 

Icr242005

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Follow up, make sure you do as Jiggz said. I have replace many many head gasket and have never retorqued on my 2 stroke engines. only car motors, but I was shocked on how much I had to tighten to get back to spec. I have always went to torque in 3 passes and work from inside out pattern.
 
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