Mercury - Water Separating Fuel Filter MerCruiser 3.0L V6 Diesel Marine-Grade Construction 8M0135210. Overview. If you've spent enough time on the water, you know fuel quality can make or break a trip. One day everything runs clean and smooth; the next, a little moisture in the system can turn a simple cruise into a frustrating afternoon. That's why a dependable water separating fuel filter isn't just a convenience - it's peace of mind. The Mercury Marine part 8M0135210 is built for the kind of