Logo
FULL SITE MENU

New head gasket leaking, start over or?

C

code1p36

Regular Contributor
I just replaced my original head gasket with a Sierra and per a couple reputable sources did not coat it with Gasket Sealer. I started it up last night and almost immediately saw water coming out of several of the center head bolt heads and one tiny drop between powerhead and cylinder head. I retorqued in sequence again up to the 20 ft lb and it sealed up all but a very very small amount of the water coming out of one of the head bolts. I checked spark plugs and they were not wet so I am fairly confident water is not getting in there.

The head was not overheated before and appeared flat and I sanded it down with 220 on a flat surface and had everything very clean. I am betting if I would have used Gasket Sealer like the book calls for I wouldn’t have this problem but a couple experienced professionals recommended not using any sealer due to that it could affect proper torque specs.

With this very very small leak should I slightly torque more or start over with a new head gasket, run a couple more heat/cool cycles? Or, should the Sierra head gasket seal itself up? It was kind of shiny black, so will that seal itself through a couple heat/cool cycles? I have heard of the heat activated head gaskets. If I do start over I will sand down the cylinder head even more but should I use Gasket Sealer? The motor is a 3 cylinder 2000 60 HP and the OMC book calls for Gasket Sealer so why not use it like the factory calls for it?

Also, the gasket can go in both ways but I replicated how the factory one was installed because the rings were more flush on one side and rolled slightly different compared to the other. Should the factory lettering and stamping be faced a certain way?

Thanks in advance.
 
Last edited:
First, let me say that I'm not familiar with your particular model. Having said that, the general rule is that pre-coated gaskets should not get any added sealer. However, I'm wondering if perhaps the bolt holes are drilled all the way through to the water jackets and the leak is along the length of the bolt threads and not across the gasket? Consider removing the leaking bolts one at a time and apply sealer to the threads. Hey, nothing to lose at this point.
 
I don't believe the bolts go all the way through because the book also calls for clean threads on head bolts with no sealer. My concern with not starting over is if any of that water got into the cylinders or if it still can since my original starting of this a couple nights ago didn't have a good seal.
 
Strange.... In my 30+ years at the bench, and installing 3 or 4 head gaskets in that time, and being taught from day one by OMC master mechanics to put nothing but oil on the head gasket.... due to your post entry, I had to double check a few service manuals.

It does state to apply "Gasket Sealer Compound" to both sides of the gaskets... BUT... it does not state which gaskets, does not specify in particular "Head Gasket"... and I believe this recommendation to be an oversight (a play failure of words) as if one started coating carburetor gaskets with that gasket sealing compound... one would be asking for fuel related problems with a capital "T"! The reasoning for no sealer on a head gasket escapes me... BUT... I found it's best to follow the instructions of ones mentor.

Yes, I'm aware that various gaskets, later in years, have a glossy finish, a sealer that seals via heat that usually has the instructions on it stating "Apply No Sealer" that sorta insinuates that a plain gasket should have that sealer (sigh)... Trust me (as the ole carny says) just use the oil.

If the gasket is the proper one, is good, is not installed backwards (possible in some cases), and is torqued in its proper sequence, it will not leak... UNLESS... a problem lies elsewhere, usually a warped or corroded head/block.

In the 30+ years mentioned, a leakage such as you bring to light here is a first for me. When you find the cause, I'd appreciate having it brought to our attention.
 
Last edited:
Joe, it states in my manual which is specific to the 2000 40-70 HP (P/N 787069) to 'Lightly coat both sides of a new cylinder head gasket with OMC Gasket Sealing Compound.' I am pretty sure that Sierra gasket I installed didn't mention to not use sealer.

If it leaks the next time I run it, I will replace the gasket and double check for flatness.

But first, if the leak is stopped is there any chance I could have gotten water in cylinders on that first start up and continue to now?
 
I'll accept your word that the service manual states what you say my friend as I did retire in 1991, and perhaps in later years a sealer is required for some reason.

However, in your initial post, what you had to say about the water actually leaking from the the head bolts... that is describing water flowing up the clearance space between the bolt shaft and the bolt hole in the cylinder head? I fail to understand how this is possible. Flawed gasket perhaps?

A new gasket, torqued to the proper specifications, in the proper sequence... and leaking like that?

Keep us informed.
 
I just ran it tonight for a short time and no leaks! That gasket must have sealed itself up after the last round of slightly more torqueing after the first set of leaks. I am pretty sure I didn't have the final sequence of torqueing tight enough since after the first major leak it did take a good amount of turn to get up to the 20 ft lbs. Maybe my torque wrench end loosened up on me? Not sure but I sure hope it is good to go now!
 
code1p36 said:
I just ran it tonight for a short time and no leaks! That gasket must have sealed itself up after the last round of slightly more torqueing after the first set of leaks. I am pretty sure I didn't have the final sequence of torqueing tight enough since after the first major leak it did take a good amount of turn to get up to the 20 ft lbs. Maybe my torque wrench end loosened up on me? Not sure but I sure hope it is good to go now!
Click to expand...

Every reman Yamaha or J/E OB I have done Leaks water profusely until the engine is run up to temp. Re torqued after first heat cycle and no leaks.
 
Back
Top