Cracked Block saga continues

[Richard Cavanagh]

My '96 Johnson 115 had 2 cracks in the water jacket which I had welded. The welder went onto slightly grind the area where the head gasket seals the jacket to the head. I believe the combustion seal is good, but it is still leaking water from the gasket, but not the welded cracks. Is there a combo fix of 2 head gaskets, and/or RTV that might seal the head gasket/jacket seal? Perhaps black RTV allowed to cure before the head being torqued might work? I can use any help someone might offer.

 

[petryshyn]

Re: Cracked Block saga continues

2 gaskets will drop the compression. Don't glue it! Did you resurface the head and the deck, or atleast check them for warpage?

 

[Yepblaze]

Re: Cracked Block saga continues

By hand, run a LARGE, fine cut, mill file, across the surfaces. It can help give you an indication of the flatness of the surface. Do it carefully while adding pressure in the middle of the contact area. It's possible to actually clean up surfaces that way to a point but much care must be taken to not screw it up more than improve. Do not run the file back and forth in only one direction. Go vertical, diag, horiz, ect.<br /><br />Sounds like you have a decent idea of the task at hand. Partially set RTV make a gasket stuff might help you out. Perhaps you could double up the gaskets (although you increase the blow out risk) along with having the heads shaved enough to make up the two gasket difference.

 

[Richard Cavanagh]

Re: Cracked Block saga continues

The head is flat. The jacket is flat except for the water seal area around the welded edge. Combustion seal is ok.

 

[Dhadley]

Re: Cracked Block saga continues

If the gaskets were made like the GM "tin" gaskets and would interlock two would work. But they aren't. Oh well!<br /><br />I would suggest that after you deck the block (the less the better) to get it straight, check the heads for straightness. Surface the heads (not cut them) if needed and use the OMC "fat" head gaskets. You will find the part numbers on service bulletin 1155 (I think).<br /><br />Good luck!

 

[petryshyn]

Re: Cracked Block saga continues

If compression surface area is OK and the head is flat, then try using one headgasket and loctite 518 with the primer #7649. Its good stuff and can take a beatin'<br />Do not loctite the compression surfaces<br /><br />everything is an experiment at this point

 

[Yepblaze]

Re: Cracked Block saga continues

JB Weld is a bit runny. I believe Marine-tex is a bit more bondo like. Either can be used as filler. Do a search for marine-tex at west marine's website http://www.westmarine.com

 

[THard]

Re: Cracked Block saga continues

I recently did a fix with marine tex and its holding up fine but I've had several shops tell me they like JB Weld because of the temp it withstands could be old timers talk though. Good luck.