I have a 25HP Mercury four stoke engine. The last few times I have checked the oil, when I remove the dip stick oil flows out of the dip stick receptacle. I am certain that when the oil was changed we replaced it per the manufacture instructions. The engine I think the engine was manufactured ny Tohatsu. Talked to them and they indicated the engine could actually produce oil causing this problem. Anyone ever heard of this.

My Tohatsu 25 4 stroke is a 2003 and it's been gaining oil all the time that I have owned it. When I change the oil I just add a little under 2 quarts and when it shows over full.about 5 to 6 months of running then I just change it again. I have noticed the more slow troll I do the faster it gains oil. Also I even put a inline shut off on it and that didn't stop it all the way.

sounds like piston ring by pass. what was the break in procedure?

Its diluted fuel passing by the rings from not being broken in properly or being over propped and not reaching max rpm's. If the rpms are good change the oil and run it wide open for an hour or so. This will seat the rings fix your problem.