Only Mercury avoids this sobering expense in its high-performance four-stroke engines by offering self-adjusting valve trains. So we weren’t surprised to see self-adjusting valves in these new 75-, 90- and 115-horsepower models. Besides that, when the motors returned from the fat farm they came back in a svelte streamlined shape, visibly more trim than in the previous model. They lost weight too, making the 115 the lightest outboard in its class — and with big, smooth-running four-cylinder displacement. They meet all the California Air Resources Board (CARB) and Environmental Protection Agency requirements, naturally, and after test-running the powerful 115s near the Fond du Lac, Wisconsin, factory, we think they are a hit.