We had this Mercury outboard sitting in the shop for at least three years know, if not longer. The engine looks hardly used, if never used at all, it really looks brand new. Anyways we put in on a boat, fresh fuel, engine started right up, just had to let it run for a while for it to idle on it's own. I noticed there was an oily mixture coming out of the exhaust port??? It is a small hole right below the latch for the engine cover. Also after running it for a little while the inside of the prop was covered in a oily mixture too. Checked oil level and is fine. The oily discharge seemed to get less after running for a while. We carried the engine down to the boat sideways, maybe this was the problem or from sitting for so long?