Mercury - Vented Splash Cover FourStroke Series Black Polysoft II Fabric 8M0228503. Overview. A 50 horsepower FourStroke is the sweet spot for a lot of boats. It's big enough to get you where you're going without feeling strained, but still simple, efficient, and easy to live with. The thing is, those motors usually see a lot of everyday use-ramps, docks, trailering dust, and plenty of spray when the wind turns your ride home into a wet one. This splash cover is for that real life.. It's a small