Getting boat ready tonight to head to Rayburn early in the morning and decided to check the lower unit oil since I havnt checked it in about 4 months. Pulled the bottom plug and about 6 drops of clean looking water comes out kinda slowly, I crack the top plug and greyish thick oil comes out with a good amout of real fine metal shavings in the oil. I have a 97 mariner 225 EFI with a aftermarket SEI lower unit that ive had for about 6 years with no problems. Whats weird to me is why its not chocolate milk looking if it has water in it. Im thinking it will be fine to go fishing tomorrow just wont run big motor very much. What would yall do? Fish or no?

same thing happened to mine. the water will seperate from the oil. it had a bad seal.

I would drain it and look for big chunks or flakes if it is just like graphite looking put fresh oil in, pull prop and check for line around shaft and run easy, recheck after fishing trip.

Ok if it has line around the prop is the seal easy to change out? I change seals out at work but never have messed with lower unit seals.

Leaking seal is pretty common. Last one we had was cause the shaft was slightly bent and eventually wore the seal enough to leak.

you need to do a pressure test to see where leak is otherwise you are just chasing it. a simple bicycle pump, hose and soapy water is all you need

Change the oil
Go fishing and worry about it when you get back

+1 you'll be fine this weekend... ASAP after that

It worked this long. change the oil and go fish.

I change mine at the end of winter every year. Fishing in cold water will cause condensation build up one everything warms up. Not saying you don't need to get it checked but I have seen that before.

You have to pull the prop shaft to change out the seals and O-rings. It's a pain but you can most likely do it. Like the guys have said, it might have been fishing line (braid is horrible) getting around the shaft and eating up the seal or you may have a slightly bent prop shaft.

The shaft doesn't have to be out of round by much either.

change oil, fish, take to shop.

Hmm, I'm just the opposite. I change mine every fall right before it gets cold. My theory is I want to make sure there is NO water in it when its getting below freezing.

This, change before it gets cold. But I do use all winter. Just peace of mind there is no water in lower unit heading into winter.