67 188hp mariner trouble

[mlryan]

I have a 1967 188hp inboard mariner w/ holley carborator. I went motoring to day and had a problem with this coffey looking oil coming out of the thing that looks like a tuna can on top of the vlave cover but only when i run at full throttle. I checked the oil and its the same color and is 5 times the original volume. What is this stuff coming out of the top of the engine and whats causing this problem, because im probably guessing it cant be good

 

[WillyBWright]

Re: 67 188hp mariner trouble

No it can't. Must be water getting in the block. Could be freeze damage. That's so old it might have just rusted through. Coffee color seems too dark unless you use a lot of cream. Water will make the oil creamy. Gas would retain the brown color, but the smell would be obvious.