If salt water sat on the top of the piston, it also ran down past the ring.
Rings are not a water proof seal.

"Russell Hermansen" wrote in message
. ..
I discovered I had a head gasket failure on the right side of my 1985
Evinrude 175 HP outboard. The plugs were fouled with sea water as was the
cylinders. I sprayed the cylinder bores with anti-sieze lubricant after
cleaning them, this after removing the head to get to the gasket. My
thermostat and pressure relief valve were also junk from the corrosive
power
of salt. I am replacing the head gasket and the other parts. Could this
sea water have gotten past the piston rings and into the crankcase. Is
there anything else I should address because of this problem? Your
concern
and comments are appreciated from this novice wrench. Russell
Hermansen