crack in exhaust port

[Grizzly]

I followed the Woywoyboy thread, as his problems seemed be so similar to my own. I finished stripping down my engine last night. 1973 850 Mercury. When I took off the exhaust cover, the block was cracked, about 1 1/4" by #4 port where molding separates the exhaust from the water jacket. I tried to send a picture. I couldn't but I'll try again. Below the crack, the black cabon deposits change to creamy white. Could this be the source of water in the gear lube as well? Or is that a separate problem? Has anyone had any success repairing such damage. Any suggestions? A new block is not an option for me, at this point. I appreciate all replies,as always. -G.

 

[Ross J]

Re: crack in exhaust port

Hi Grizzly,<br />There's the process of "stitching" which is building up a weld to repair the crack. I'm informed by our local expert that it isn't considered a good repair, however he knows of folk who are happy with this procedure. I guess the welder has to be a knowledgable sort up with that technique. Cost would be the best factor. I'm not an expert but thats my 2 cents worth..........<br />Ross

 

[Grizzly]

Re: crack in exhaust port

Thanks Ross, That is very encouraging. I wonder if I need to open up the crack with a dremmel tool before I take it to the shop.

 

[Ross J]

Re: crack in exhaust port

I don't think I'd want to touch the crack because of the risk of making it run a little. The shop would know the best approach. I'm guessing they would grind some out first anyway, again I don't know for sure and this is only speculation.

 

[Grizzly]

Re: crack in exhaust port

Good news! The piece with the crack comes off. I couldn't tell because of all the carbon. Lotsa bolts must serve a purpose..Duh<br />Manifold? 3 1/2 ports about 3 1/2" wide, crack in bottom (1/2 port). Now! Could this also be the source of water in the lower unit lube? If not where do I go next? I appreciate your patience, I've got a lot to learn about my motor. Never was able to send pictures, AOL tech said I needed a web page. As always, I appreciate your replies. Clymer is vague in these areas.-G.

 

[petryshyn]

Re: crack in exhaust port

Sorry Griz......separate problem.....do a vacuum pressure test. If you don't have the tools, drain oil thoroughly (let drip over night) replace fill and vent screw gaskets, refill properly and try again.(check it often) These are a common source of leak. Hate to pull it down for nothing.....its worth a try!<br /><br />

 

[Grizzly]

Re: crack in exhaust port

Thanks Schematic, Thats what I needed to know. Local dealer said that was not a crack in the manifold, thinks it was leaky gasket. Ordered new gaskets, will call and order new LU seals as I have already tried replacing the lube. Nuttin to it but ta doit. Have a great day! -G.