Oil leaking out of the prop

[deputydan]

I bought a newer boat with only about 10 hours of use on the engine (25 Mercury Optimax). After fishing the other day, I noticed a little bit of oil leaking out of the prop. Is it possible that the gas that was already with the boat was mixed too rich and is working it's way out the exhaust, or should I be more worried? I figured who else better to ask than all you guys. I'd appreciate any input.

[Pat K]

It's common for unburned oil to drip out the through hub exhaust.

Pull the bottom plug on the lower unit just to make sure it's not leaking. If the lube looks like oil, not milky you should be fine.

Pat K

[icecold]

If the oil is black it is unburnt gas oil mix if it is yellowish or clearer type oil it is gear oil, then you might have a prop shaft seal leak