Water in oil

[jonwebb]

I have 1986 Renken with a 4.3L

I have 1986 Renken with a 4.3L OMC with a Cobra outdrive.The boat runs great in my yard with the hose hooked up to it.I have had the boat in the lake 2 times since I bought it.Both times the oil had water mix with it.Its like as soon as the outdrive is submerged the oil mixes with water in the crankcase.When I pull the spark plugs they are perfect so not in the cylinders.The boat remains running great even with the oil mixing with water.In my yard with the water hose hooked up to it and clean oil in it you can run it as long as you want to and it does not mix at all. Any Suguestions?????

 

[hystat]

have to be something about the

have to be something about the angle the boat sits on the trailer vs. in the water. weird one for sure.

a pressure test of the cooling system is first step.

 

[justintime]

risers are clogged

risers are clogged

 

[arcrat]

Blowed head gasket

Blowed head gasket