The Adaptive Speed Control feature lets you maintain engine rpm despite changes in load or conditions. Climbing large swells is easier. Cruising at low speeds is smoother. Carving out tight turns is effortless.
FourStroke 250-300hp
4.6L V8
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.
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Intuitive, Innovative Features
Adaptive Speed Control
Smooth and Quiet
Featuring a large muffler and a vibration-dampening cowl design, Mercury V8 FourStroke outboards deliver an exceptionally smooth, quiet ride at any speed.
Easy to Maintain
The exclusive Top Cowl Service Door simplifies routine maintenance, letting you check or add engine oil without removing the top cowl. An hour-based maintenance schedule decal is located under the cowl, providing a quick overview of routine maintenance.
Ample Charging Output
A powerful alternator delivers 85 amps of charging power at wide-open throttle – perfect for keeping onboard electronics running long into the fun.
Industry-Exclusive Battery Management Technology
When needed, the idle charge battery management system works for you by monitoring battery voltage and adjusting engine rpm at idle to boost alternator output.
FourStroke Performance Data
Exceptionally Smooth & Quiet
The V8 300hp FourStroke outboard is 33% quieter at cruise with 30% less transmitted vibration at idle than the leading four-stroke competitor.
High Displacement
The high-displacement, quad-cam design of the V8 FourStroke powerhead generates serious torque, especially at mid-range, for quick acceleration and exciting speeds.
Light & Compact
The V8 300hp FourStroke outboard is the lightest in the 300hp class by more than 20 pounds. Both V8 models mount on 26-inch centers for easy repowers or new installation on a wide range of boats.
FourStroke Advantage
Comfort
With a balanced powerhead and sophisticated, vibration-dampening cowl design, Mercury FourStroke outboards deliver an exceptionally smooth and quiet ride at any speed.
Durability
Premium corrosion-preventive technologies and durable components ensure FourStroke outboards can stand up to the most demanding marine environments.
Compact Design
Ideal for new engine setups or repowers, the slender width of a Mercury FourStroke outboard fits most transoms, including those with narrow engine wells and tight motor spacing.
Efficiency
Explore farther and stay out longer thanks to impressive power-to-weight ratios, intelligent fuel systems and optimized fuel injection (on most models) that maximize performance from every drop of fuel.
Specifications
SmartCraft® The Power to Do More
Mercury SmartCraft® digital technologies refine the entire boating experience to ensure every day on the water reaches its full potential. From intelligent gauges and displays to advanced systems that make boat control easy, SmartCraft gives you the power to do more with your time on the water.
SmartCraft compatibility is available for Mercury engines 2004 and newer, 40hp and above; 2022 and newer, 25hp and above. Features vary based on controls and engine models.
Repower Your Boat with a New Outboard
It’s simple. When you repower your boat with a new Mercury outboard, you get to keep making memories in a boat you love, while enjoying the reliability, performance and efficiency that a new engine brings.
Warranty & Maintenance
Warranty Coverage
Mercury makes world-class marine products backed by world-class warranties.
Maintenance
At Mercury, we make maintenance easy. Learn more about how to keep your Mercury products performing at their peak.
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Adventure Starts at Your Mercury Dealer
Your local Mercury Authorized Dealer is the best place to see and purchase Mercury engines, parts and accessories, and to get expert support when you need it.