Looks like a double double

[SSCARVER]

Hello good to be here,
Right up front I'll tell you I don't know diddley about boat motors but I do like fishing so 2 years ago I bought a 25 hp Mercury attached to a 14' Starcraft, ran just fine as far as I'm concerned.
Last year I stored in a heated garage so I figured no need to winterize it.
This year I checked the lower end and the oil came out looking just like coffee loaded with cream, so that's not good.
What would it most likely be?

 

[GA_Boater]

Welcome to iboats, SS. One or two or three or four or five of your seals in the lower unit are leaking, most likely. There are quite a few lower unit pressure/vacuum testing topics and procedures in the forums you can use to isolate which one. I don't have a link to one handy right now, but a search in the upper right corner should find one. Good luck.

 

[MH Hawker]

A pressure test with the LU removed and some soap water will show what seals are leaking.