Lubricant Requirements for Today's Outboards

The most important, and obvious, requirement of a lubricant is that it lubricate. In outboard engines, the stress the lubricant is placed under can also be affected by its deposit producing characteristics.

No reliable screening means appears available to study deposit forming tendencies and full-scale engine tests have to be undertaken. Some data from such tests are presented. A reasonably accurate means is available, however, to screen the lubricating ability of oils. This technique is discussed, and data obtained by it are presented.