About 10 years ago, I bought a rebuilt 1985 yamaha 40 two stroke. The dealer I bought it from gave me a small bottle of this ring free additive and said to add a teaspoon per 5 gallons. The engine has run flawlwessly all along. My question is, as I just bought a '99 115 Yamaha two stroke, for a different boat, should I use in this as well ? One thing to consider is the 40 hp has 6 gallon tanks that get used up regularly. The 115 hp has a 40 gallon tank that gets mixed with the winterizing fluid.
<br />The (just a start) part, though I think I said "A minimum standard".<br /><br />For the price of the oil and the ring free, you could buy a top of the line full synthetic and be better off all the way around.