I noticed there was a bit of oil in my bilge area after a day on the lake last weekend. I know the bilge area was pretty dirty, so it may be that. But I went and checked the oil today and I'm not sure where I stand. The dip stick looked good -- I think. The inside of the oil fill area looked a little grey. I attached pictures. I know there is a small crack in the water jacket, but my mechanic said that's all it is, and it's tiny - he wasn't worried about it. The guy I bought the boat from stored it outside with no cover. And the gas tank had quite a bit of water it in too. Could water have gotten into the top of the engine from rain? And at the end of the day, what should I do to clean it out? And do I need to clean it up asap?