I believe 2 strokes are built for WOT or close to it but 4 strokes will last a
lot longer if you keep them under 4000 RPM most of the time. It is simply the
number of reciprocating parts. Most of my hours are put on under 3500 RPM ...
but I want it to last 2000 hours. So does Mercury, because it will be under
warranty for about that long at my current usage.