I have a 3.0L inboard stern drive volvo penta engine. It is a basic 4 cylinder GM motor. It seems to burn a little oil and smokes more than it should. Is there an additive I could add to the oil to help with carbon build up and possibly helping the piston rings not allowing it to burn oil and smoke? All these additives claim to do so much, don't know who to believe. I actually went out and bought Sea Foam, haven't used it yet, then saw your video with you saying not to use Sea Foam.
Thank you,
George.
Sea Foam was really designed for use in 2-stroke engines.
You might try ATS Carbon Clean which Scotty has talked about on several occasions. It may help if the problem is due to carbon buildup and stuck rings, but if the engine is wearing out no additive will help with that.
Well actually you could use mineral oil, full synthetic leaves worse carbon that is harder to burn and dispose. Mineral burns better.
You can also try puting onto the pistons directly over night GOOD carbon cleaner, it will soak over and disolve any carbon that is in the rings. If there is any. It actualy works if there is any carbon on the rings.