Two-Stroke Cycle, Liquid Cooled, Engine Lubricating Oils

The paper describes areas of unsatisfactory performance of most commercial outboard oils being marketed today. It describes the short-term testing techniques used to evaluate lubricating oils at Outboard Marine Engineering. These techniques evaluate oil performance with respect to deposits in the combustion chamber and on the piston skirts, piston ring sticking, lubrication ability, spark plug life, and preignition tendencies. Long-term testing techniques are also described. Finally, an ashless oil using an amide type additive with outstanding performance is described and its performance characteristics are shown.