Mercury - Fuel Filter Kit Water-Separating Fuel System Marine Filtration Assembly 8M0088825. Overview. Anyone who's run a small outboard for long enough knows how quickly a great day on the water can turn sour when fuel isn't clean. A sputter at idle, a stumble when you throttle up - it all points to the same quiet culprit hiding in the fuel line. The Mercury 8M0088825 Fuel Filter Kit brings back that sense of confidence you want every time you pull away from the dock. It keeps your outboard bre