1985 Merc 50 hp elpt with water leak

[crna72]

My mercury has water leaking out of a small whole next to the top spark plug. A fair amount comes out and there is not any water coming out of the pisser. Starts just fine and runs pretty good, though it does tend to bog down on top-end occasionally. However, when I was going through my boat this spring getting it ready, I became aware of this water leak. Thanks for your help!

 

[Texasmark]

Water jacket gasket leak. Water jacket is that flat plate on the full length of the rear of the engine block. They probably have a replacement for sale here on iboats. The screws like to break off so lots of fine quality penetrating oil and don't twist them till they break. Get a boxed end wrench and a hammer. Use the hammer as an impact tool with multiple smacks until the bolts start moving then you can remove in the usual fashion. On reassy, clean all the threads, tap on block and wire brush on bolts and install a blue thread locking compound which will hold the bolts in place like a lock washer and will also act as an anti corrosive element making removal easier next time you are there.

Since that engine is probably a classic block it has no thermostat so no pee means impeller in the water pump in need of replacement (iboats has them too) or clogged pee tube. Dirt dobbers love to clog that hole.

Mark