Mercury - Water Separating and Sensing Fuel Filter Kit Fuel Protection Series Metal & Composite Assembly 8M0157708. Overview. If you've spent enough time on the water, you already know how unpredictable fuel can be. Some days it's clean and fresh; other days you can almost feel the engine hesitate, like it's second-guessing what just ran through the lines. That's why a dependable filtration system matters so much - and why this Mercury Marine part earns a spot in so many boats. The 8M0157708 Wat