25 hp Johnson with a hole in the head

Took the boat out the other day and as I was running across the bay I noticed that a lot of water coming out from under the cowling. I pulled it of and was suprised by a stream of water shooting high in the air from the top of head on the motor. It looks like a metal wire clip has over the years been in contact with the head and electrolysis had taken over. It pitted the head bad enough to form a weak spot and finally sprung a leak in the water jacket. The area that is damaged is only about 1/4 inch in diameter and the hole is only about an 1/8. Is there a safe way to patch this hole? Maybe thread it with a tap and put some kind of plastic screw in it. Or a metal one that wont cause any more electrolysis? Or just JB weld it?

Re: 25 hp Johnson with a hole in the head

What year is your motor? Different years have differently designed cooling passages. Could you post a picture?

Re: 25 hp Johnson with a hole in the head

I'd clean all the paint off of the area, ruff it it up and patch it with gray Marine Tex.

Re: 25 hp Johnson with a hole in the head

Sorry for the late reply but at the time my boat is being stored pretty far way from my house so it take me a while to get pictures. Here they are.

Re: 25 hp Johnson with a hole in the head

I'd still do what I said in my last post.

Re: 25 hp Johnson with a hole in the head

I just looked at what Marine tex is. Yeah, that should work. There is not any real amount of water pressure there. I did a temp fix to get me back to the lunch ramp by wittling a small branch I found in the front of my boat to fit in the hole. That Marine Tex looks more than strong enough to fix it.
Thanks
Terre

Re: 25 hp Johnson with a hole in the head

Actually, if you have it fairly thick, you can drill and tap it. I've had better luck with the gray stuff.

Re: 25 hp Johnson with a hole in the head

How in the hell did you get a hole there?? That is just plain odd. If you don't mind removing the head, a good welder can tig weld it shut.

Re: 25 hp Johnson with a hole in the head

If a small branch can stop the water leak I'm sure Marine Tex would. Saves taking the head off and getting a new gasket and ect. Read the first post again.