When you buy a new boat motor, you probably want to keep it running as long as possible since motors are not exactly cheap. For my father, purchasing his mercury engine was a huge investment. He had been using an engine that his father had used on his old boat, but since this motor was old, it didn’t last very long.
When he made the switch to his new motor, he liked it a lot better because it ran smoother. To keep it running smoothly, he maintained it regularly. This was part of keeping the warranty valid. He also got rid of the cheap off brand oil that he’d used for the old motor and started using Mercury 2 stroke oil.