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.
Featured videos
Featured resources
Learn more about how Mercury makes great days on the water possible.
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 and 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 centres for easy repowering or new installation on a wide range of boats.
FourStroke Advantages
Corrosion Resistance
Advanced alloys. Durable coatings. Sealed electronics. Easy-to-use freshwater flush system. Fourstroke outboards come packed with premium corrosion-preventive technology that enables them to stand up to the most demanding marine environments.
Superior Control
With a choice of tiller or remote steering and compatibility with advanced SmartCraft® features such as Troll Control and Active Trim, you can optimise your engine for total command of all your adventures.
Go Farther
A host of efficiency-enhancing features such as Advanced Range Optimisation (ARO), a closed-loop fuel system and a hydrodynamic gearcase optimise fuel economy so you can go farther on every tank.
Power and Flexibility
A Mercury 250 or 300hp fourstroke outboard is the answer for fishing, cruising or all-around fun. They are ideal for powering a range of boats and come in four colour options to match your boat and style.
Engine Specifications by Horsepower
SmartCraft® The power to do more
SmartCraft® is a full suite of digital technologies, fully integrated and totally coordinated. Gauges, sensors, vessel systems, computer-controlled features – one total package, one high level of control. Make your boating experience easier, safer and a lot more enjoyable.
Time for new power?
Replacing an old outboard can deliver improved performance and reliability, increased fuel economy and better handling for a more enjoyable boating experience. The entire family of fourstroke outboards is lightweight and compact, making those engines perfect for repowering older boats.
Warranty & maintenance
Warranty coverage
Mercury makes world-class marine products backed by world-class warranties. You can also add a Mercury Product Protection (MPP) extended service contract that covers certain expenses caused by defects in materials and workmanship after the Mercury Limited Warranty expires.
Maintenance
Mercury fourstroke outboards are thoughtfully designed to minimise maintenance and ensure you get the most from your time on the water.
Get the latest Mercury News
Sign up for our email list to be among the first to hear the latest Mercury product updates and news.
Resources for you
Find your manual
Download a digital product manual or order a printed version.
Learn more
Brochures
Explore Mercury products and learn more about what it means to Go Boldly®.
The best products have the best dealers
When you make the best marine products in the world, you want the best dealers behind them. That is why we ensure that Mercury dealers are the best equipped to sell and service our products. Your Mercury authorised dealer is the place to see and purchase Mercury engines as well as genuine Mercury Precision Parts® and accessories. With thousands of dealers, you can rest assured we are always close by and ready to help you Go Boldly®.