Water leak from plate near spark plugs on mercury

[mvale5]

Hi can some one tell me how to replace the head ( I think that's what it's called) it's the plate that the spark plugs screw into on my late 1970 early 1980 mercury 85 Hp out board,
The problem is that after the impeller broke on me now I fixed that but when I start the engine I have water leaking out of this plate just near the spark plug and close to the water outlet, I can see the crack in it
Also could there be any other damage to the motor? it starts fine and runs on all 4 cylinders just like nothing is wrong
I am hoping this is a easy and not to costly fix
Thank you in advance

 

[racerone]

Fact---The sparkplug does not screw into that plate !----------Just remove the plate ( water jacket cover ) and change the gasket.--------If you see a crack near the sparkplug than that is another totally different issue.--------First pull the plate off to inspect.

 

[Chris1956]

Gee, changing that gasket can break some bolts.. If the leak is minor, dry it out and use some silicone caulk to seal the leaks.

 

[mvale5]

Actually once I pulled the plate off I found out that it was just a simple cover, as I have never touched a outboard motor before I do not know all the correct terms or names of things I was guessing it was the head, but the crack in the water jacket is around 3cm long and I did get it off without breaking any bolts but thank you for all your advice it is most welcome

 

[Texasmark]

Mercury didn't use a separate head on it's engines for years. The engine block casting contained the head. The cover is merely the water jacket cover. Later on, in their larger V engines things changed. OMC did use a separate head and water jacket cover (2 gaskets, 2 covers) for years. Don't know what they are currently doing....last OMC I had was a 1975 70 HP.

 

[quicktach]

When you put on the new cover, torque as per your manual. Put some never-seize on the bolt threads.

 

[Mi duckdown]

NO Serial Number.?? NO Pics.??