Salt deposits on cylinder head 8hp Johnson

"I bought a 2000 8 hp extra lo

"I bought a 2000 8 hp extra long shaft outboard a year ago for trolling and auxiliary on my 28'displacement craft. It worked wonderfully this season, a great relacement for the Seagull.
When I brought it home for maintenance recently I discovered considerable salt deposits on the cylinder heard, around the spark plug bosses and ridges. Where would it come from? Could it be a pin hole leak in the head gasket that allows salt water to ooze out and evaporate. It is stored horizontally on the swim grid when not in use. The cowl seems to fit well and tight. The deposits were only on the cylinder head surface into which the spark plugs screw."

"Grant, sounds like your think

"Grant, sounds like your thinking along the right line. Could be a bad head gasket allowing a little bit of water into the cylinders.

Gaskets are cheap, and not difficult to change. Probably worth doing - even just to rule it out as the issue..."

"I have discovered the source

"I have discovered the source of the leak. there is a small chip out the edge of the plastic thermostat cover. So all I need do is get new thermostat cover. Something else about this engine, I drained and replaced the bottom end gear lube, the old stuff was very dark, almost black - any thoughts on that"

just old. change it every year

just old. change it every year.