Mercury - Tow N Stow Outboard Cover 40-60 Horsepower FourStroke Series Polysoft II Fabric 8M0221490. Overview. There's a certain peace that comes from knowing your outboard is protected, whether you're trailering down a dusty backroad or leaving the boat tied up overnight after a long day on the water. A good engine cover doesn't just guard against the obvious things-it saves you from those small frustrations that add up over time: scuffs, sun fade, grit, salt, and whatever else the day throws a