Mercury - Inline Fuel Filter Kit Fuel System Protection Marine-Grade Construction 864572A1. Overview. If you've spent enough time on the water, you know how quickly a perfect day can sour when fuel delivery starts acting up. A sputter here, a rough idle there-and suddenly you're drifting instead of cruising. That's why a dependable inline fuel filter matters more than most people realize. The Mercury Marine 864572A1 Inline Fuel Filter Kit gives you that steady, quiet confidence. It cleans the fu