water in the oil

[Peter Leger]

I have a 1980 165 merc. The engine runs great. Starts up quickly, runs smooth with no vibration but I have water in the oil. I bought the boat 3 weeks ago. The previous owner son said the boat has been sitting for about 4 or 5 years. I changed the oil twice and I'm thinking about doing a compression test. I don't think its a head gasket as it is running so smooth. Any feedback before I take motor apart?<BR>

 

[guyjg]

Pull the spark plugs and examine their condition. Also check for water intrusion in one or more cylinders. If you are lucky it may just be a cracked exhaust manifold or gasket. If not it could be a cracked head, head gasket or the worst scenario; a cracked block. If there is no evidence of water in the cylinders perform a compression test on a warm engine w/carb wide open, the ignition disabled and all spark plugs removed.