Meecury, 25 hp 4 stroke efi , 2013
(West Branch, Michigan )
It has been having a problem running under power , 1/2 throttle or more it will run up fine than all of a sudden start missing and running rough ,pull the throttle back and its fine than give it gas and its fine to full throttle, might run fine for the rest of the day and then the next time out its acting up again, it will putt the pontoon around the lake all day long at idle or just above, tried new fuel, filter, fuel line, fuel supply, new spark plugs, (looked fine and all the same) . This has been going on an off for 3 seasons, it gets fresh oil and filter , fogging, and anti freeze ran through it just to make sure. Now why im here, I warmed it up on the hose today and than pulled the oil drain and the oil coming out looked like chocolate milk , thin with white glops at the bottom. So I have water in my oil , dam it, this thing hardly has any hours on it. Im a has been mechanic, I can take it apparent, I don't want to!! Do any of you have any advice before it pull the guts out of this P.O.S. Thanks for letting me get this off my chest sincerely, Mercury hater never again .