Mercury 300 HP Racing V8 Outboard Engine with Electro-Hydraulic Steering, Trim, Tilt, and Ultra-Long Shaft

The Mercury Racing 300 XXL is a 4-stroke outboard marine engine designed for high-speed performance boats, race boats, and offshore sport boats that require an ultra-long shaft. It features a 300 HP / 224 kW and 4600 cc V8 (8-cylinder) engine. The Racing series is Mercury's high-performance outboard engine group. With a naturally aspirated high-performance engine and Racing ECU calibration, maximum power and speed are targeted.

Racing 300 XXL Series Features and Technology Advantages

High-performance ECU calibration extends the optimal power band compared to standard FourStroke engines. Precise maneuver control at high speeds is ensured with AMS electro-hydraulic steering.

• V8 (8-Cylinder) Engine (4600 cc): High-performance ECU calibration extends the optimal power band compared to standard FourStroke engines
• Ultra-Long Shaft (635 mm (25")): The propeller operates at optimal depth at the correct transom height
• High-Performance ECU: Extended power band with Racing calibration
• Electric Start: Instant activation with key or button — comfortable and quick starting
• Electric Trim & Tilt (Power Trim & Tilt): Adjust trim angle with a button while cruising — fuel efficiency optimization; fully raise the engine with tilt
• Floating External Fuel System: Connection for large capacity external tank — range determined by user needs

Ultra-Long Shaft — Which Boat Type Is It Suitable For?

The ultra-long shaft (635 mm (25")) keeps the propeller at an optimal depth in large yachts and professional boats with deep transom designs. Incorrect shaft selection will leave the propeller out of the water or scrape the bottom — measure the transom height before installation.

Technical Specifications

Who Is This Engine For?

• High-speed performance boat: Maximum speed with Racing performance configuration
• Offshore race and sport boat: Precise maneuvering at high speeds with AMS electro-hydraulic system
• Multi-engine speed-oriented configuration: Coordinated power with DTS synchronization
• Speed record and sport performance goals: Mercury Racing engineering

Maintenance and Longevity

4-stroke Mercury engines operate trouble-free for many years with regular oil changes and end-of-season maintenance protocols. The impeller of the water-cooled system should be checked every 100 hours or every two seasons. In saltwater use, freshwater flushing is mandatory after each use.

Related maintenance categories: Maintenance Kit | Engine Oil | Impeller | Mercury Spare Parts

Frequently Asked Questions

Which boat type is the Mercury Racing 300 HP engine suitable for?

The Racing series, with 300 HP, is developed for speed-oriented performance boats. It provides maximum performance in offshore race boats, catamarans, and high-speed sport boats. Weight optimization and power density are priorities for this segment.

How does the High-Performance Mercury Racing engine work?

The high-performance ECU uses different injection timing and ignition maps compared to standard FourStroke engines. The power band is optimized for high RPMs.

How is the Racing series maintained?

Racing engines require a special maintenance protocol suitable for high-performance use. Beginning-of-season and end-of-season services should be carried out at authorized Mercury service centers. Oil quality and change intervals may be more frequent than for standard FourStroke engines.

Which boat and brand are compatible with the Racing 300 XXL?

Mercury outboard motors are compatible with many fiberglass, aluminum, and inflatable boat models thanks to their universal transom clamp or transom mounting system. The only criteria are your boat's 635 mm (25") transom height and the maximum engine power approved by the manufacturer. You can confirm compatibility with Clever Marin by sharing your boat model.

Related Products and Categories

• Mercury Outboard Motors
• Mercury Marine Products
• Mercury Spare Parts
• Mercury Racing 150–300 HP
• Mercury Racing 350–500 HP
• Outboard Motors
• Boat Engines
• Maintenance Kit
• Impeller
• Anode

Is It the Right Configuration for Your Boat?

Share your boat model, transom height, and intended use — let's verify the suitability of the Mercury Racing 300 XXL engine for your boat and select the correct shaft together.