#Model-300l Color-Black. Mercury 4.6L V8 250 and 300hp FourStroke outboards deliver legendary performance and an all-around elevated boating experience. Reliability. Comfort. Power. Handling. Easy ownership. Flexibility. For any body of water and across a wide variety of boats, every facet of a Mercury FourStroke outboard is engineered to ensure you make the most of your time on the water.. Adaptive Speed Control. The Adaptive Speed Control feature lets you maintain engine rpm despite changes in