water on pistons

[Jalsp]

I have a Mercrusier 165 and had water on top of the pistons but nothing in the oil. What can cause this to happen. :'(

 

[Don S]

Re: water on pistons

Bad exhaust manifold, riser, or the gasket between them.
Water sloshing up the exhaust due to a bad exhaust shutter. This can happen with waves hitting the stern of the boat, or shutting the engine off while the boat is still moving and the wake hits the back of the boat.

 

[stevieray]

Re: water on pistons

I had a leaky cockpit cover on mine - water ran down the cushions that cover the engine compartment and - get this - right down the flame arrestor center stud & thru the carb! I had to use a vacuum pump to suck out the water from the cylinders. Squirted in some WD40 & by some dumb luck, she fired right back up. I guess the rings are in good shape since there's no water in the oil pan.