Salt, Welcome to the Forum. Milky oil is concerning, since it means there is water in the crank case. Now the big question is where did it come from? Here are some possibilities, ranging from most to lease serious)
- If you are in a cold climate, there is concerns that winterization was not done properly and you may have a cracked block/head/or blown headgasket.
-Your exhaust risers may be bad and water got into the cylinders and leaked down into the crankcase.
-Swings in temperature can cause condensation to form on the walls of the crank case and when you turned it over it mixed and got the oil milky. This is why you are recommended to change the oil in an engine every 6 months regardless of miles or hours.
So for you to get all the help you need, we need some more info. What engine, do you live in a cold climate, was the boat properly kept out of the weather while idle?
I would start with draining and refilling the oil then once the engine is running, keep a close eye on the oil and see if it turns milky again.
Keep us posted.
-JP
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