I has looking at a boat and it was immaculate, except the engine. Everything else looked pretty much new (hull and interior) but the rust on the pulley and elsewhere on engine has me concerned.













 

It does look like it has minor coolant leaks from the heads and the water pump but as long as there isnt any oil in the coolant or coolant in the oil and it dosnt blow clouds of white smoke I probably wouldnt be too worried.

I discovered with a 6.2l detroit diesel I had that the first sign of a cracked head that I had was that there was moisture in the intake manifold which was comming in from water that was evaporating in the crank case from the leak and being put into the manifold by the positive crank case ventilator valve. Eventually it got so bad that the oil turned gray and milky.

You wont really know untill you get it good and hot. Check your oil and coolant. Anything that doenst look like good clean coolant and straight oil (even if dirty) would be cause to avoid it. Same if the oil was full of rust. Also look for fuel leaks during and after running. Most of those can be fixed by tightening up hose clamps however.

One other thing I like to look for is oil leaks around the valve covers. You can find those by running your finger around the base of the valve cover on top of each head.

I wouldnt worry so much about the rust on the pullys since anything that is bare metal like where the belt runs will rust if its in a high humidity environment.

But it looks like its a clean engine which means it looks like it was cared for.
Hope that helps.

Thanks , it definitely helps.  I think I am going to schedule a sea trial and see who she looks after hot. If everything goes well I will have my mech compression test it and do all the checks.
 

Had rust on my pulleys before from a lack of running the motor.  The belts polished up the pulleys just fine after the motor was run a while.  Replacing the belts afterwards is a good idea.



 

1990's 5.7l Mercruiser with open cooling. If it has been in salt water, the exhaust manifolds and elbows are probably rotted and leaking or if not now, soon. The engine block is suspect too. Salt water and raw iron don't play well together for very long.
Electric fuel pump is not OEM, but looks to be plumbed correctly with proper marine hose/fittings.
Circulating pump (water pump in automotive terms) is likely shot too with salt water eating the bearings.
Have you read through KB's used boat thread?

Yes that thread is great.

 

Looks like water sat in the bilge and created a very humid micro-environment in the engine bay. This is common and mainly cosmetic but can cause issues with electrical components like starters and alternators.
More worrisome is the exh. manifolds etc. I mentioned.  Even fresh water takes it's toll on raw iron. Saltwater accelerates the problem. If the manifolds have been replaced you then have to ask yourself why? Most likely they were leaking water into the cylinders. If caught in time it's usually not an issue. Replace corroded manifolds and move on. If water sat in the engine for a period of time, then it may have internal corrosion issues.
Look for a water line on the sides of the engine block and condition of the starter and oil pan. Starters that have been submerged for any length of time will fail. Rusty oil pans are prone to leaks.

Thaks for the info. I think I might skip it. The dealer says its a 2013 Merc. Evidently thats BS. Correct?

I suppose it could have been re-powered. Only way to tell is get the serial number off the engine block tag located just above/behind the starter. tag is riveted to the bell housing flange. It will say "Repower" right on the tag. The accessories like alt/ PS pump look original for 1990's.
The last two digits in the hull number is the year the hull was manufactured.

All right. Thanks again. i guess it wont hurt to check I definitely appreciate the help.