Mercury - On Board Fuel Filter High-Efficiency Filtration Vapor Separator System 8M0122424. Overview. If you spend enough hours on the water, you learn that a reliable engine does not just happen-it is something you protect. Out on a windy afternoon or easing back into the marina at sunset, there is a comfort that comes from hearing your engine hum the way it should. No sputtering, no hesitation, just smooth, steady confidence. For many of us, that peace of mind starts with something as simple a