Mercury - Inline Water Separating Fuel Filter Fuel System Protection Marine-Grade Construction 8M0154753. Overview. If you've spent any time around small to mid-size outboards, you know how much peace of mind comes from clean, dependable fuel. Nothing ruins a perfect morning on the water faster than a sputtering engine caused by a little water or grit sneaking into the system. That's why boaters who want trouble-free days rely on fuel filters they can trust. The Mercury Marine part number 8M0154