Mercury Racing Ignites Performance with New 15″ Midsection

Mercury Racing® has announced the release of a new 15-inch Heavy-Duty CMS (Conventional Midsection). Purpose-built for the 200R, 300R, and the all-new 200 ROS and 300 ROS competition outboards.

Engineered for high-speed catamarans, tunnel hulls, mono hulls, and selected competition classes. This midsection delivers exceptional durability, handling, and control — even through rough conditions and aggressive turns.

Drawing on Mercury Racing’s extensive offshore experience, the newly designed 15-inch midsection incorporates a wide range of battle-tested components. Specifically, these include forged transom brackets, solid engine mounts, a single-ram trim system, and an upgraded driveshaft housing. Together, these features significantly enhance the system’s overall strength, durability, and performance.

Moreover, the midsection is fully compatible with both DTS and mechanical controls, which provides greater installation flexibility. In addition to that, it integrates seamlessly with Mercury SmartCraft® technology. Not only that, but it also supports a variety of racing accessories, including tie bars and side steering. As a result, this setup delivers a comprehensive and optimised performance package that meets the high demands of competitive and offshore boating environments.

“In six seasons of powering the P1 Superstock class with the Mercury Racing 300R and our 20-inch HD CMS. We’ve developed several upgraded components to stand up to the rigours of offshore racing,” said Jeff Broman, Director at Mercury Racing.

“Those learnings have gone straight into this new 15-inch midsection. Giving competitive and high-performance recreational boaters a new option that offers extreme durability and sharper handling thanks to a lower centre of gravity.”

Both the 200R (3.4L V6) and 300R (4.6L V8) outboards run high-RPM performance on standard 87-octane/91 RON fuel, making them a great fit for repowers or new performance builds from leading manufacturers like MTI, Skater, Eliminator, Allison, and Bass Cat.

The competition-only 300 ROS is based on the 300R platform and includes factory-installed above-water exhaust and a racing trim cylinder. It features the 5.4-inch Sport Master gearcase and is eligible for P1 Superstock, Bracket 700, and X-Cat racing classes around the world.

Also available is the V6 200 ROS — sharing the same heavy-duty midsection and built specifically for Class 3 offshore racing. Other demanding applications where responsiveness and reliability are essential.

A Partnership Fueled by Adrenaline

To celebrate the launch, motorsports icon Travis Pastrana joined the Mercury Racing team at their Wisconsin HQ to help unveil the new platform.

Earlier this year, Pastrana took to the legendary Lake X in Florida. Putting both the 300R and new 300 ROS through their paces. The launch video captured the incredible power, precision, and performance that Mercury Racing is known for.

Availability

The new 15-inch Heavy-Duty CMS for the 200R, 300R, 200 ROS, and 300 ROS will be available to order in late 2025.

To find out more about Mercury Racing’s high-performance products, visit MercuryRacing.com.