Hi, I have a 1986 170 hp merc inboard,outboard and have a little water getting in the oil.Was wondering what would be the most likely cause since I already replaced the head gasket
I think that even with a bad riser it would still be antifreeze, the seawater dumps into the exhaust way aft just above the exhaust elbow. If it is just a little, and it is not antifreeze, I would suspect condensation. If it is antifreeze, you may have gotten some into the oil when you changed the head gasket, and the oil should be changed ASAP.
