Mount the counter-rotating, 400-horsepower Mercury 400CL to eliminate starboard steering pull on twin-engine high-performance bay boats. The massive 5.7-liter block delivers brutal acceleration, pushing low-profile center consoles over steep morning swells instantly. Verifying your 20-inch transom height guarantees this counter rotating mercury outboard motor pairs safely with your starboard drive.

Eradicate extreme steering fatigue at high speeds by utilizing the integrated electro-hydraulic power steering as a seamless mechanical assist. You pilot massive twin-engine rigs with single-finger precision through rough seas. Mercury coats this 316 kg powerhouse with advanced marine primers. This physical barrier stops galvanic blistering across decades of exposure when repowering high performance bay boats.

Key Features of Mercury 400CL

- Counter-Rotating Gearcase: Cancels the massive lateral thrust of a standard engine, keeping twin-engine performance hulls tracking perfectly straight underway.
- 20-Inch Shaft Length: Fits standard high-performance transoms perfectly, keeping the gearcase profile tight to maximize top-end running speeds.
- Electronic Fuel Injection: Meters gas perfectly into the cylinders, delivering crisp throttle response and maximizing fuel efficiency across the 5800-6400 RPM range.
- Integrated Power Steering: Provides electro-hydraulic mechanical assist, delivering sports-car-like handling and zero steering fatigue during long offshore runs.
- Massive 150-Amp Alternator: Outputs unmatched electrical current continuously, keeping premium gyro-stabilizers and large chartplotter arrays fully powered.
- Multi-Stage Marine Primer: Bonds chemically to the alloy block, reflecting harsh ultraviolet light and preventing cosmetic saltwater blistering over time.
- Acoustically Tuned Exhaust: Traps low-frequency engine noise inside specialized chambers, making the massive 5.7L block nearly silent at idle.
- Top-Cowl Service Door: Lets operators check the 9.5L engine oil level rapidly on the water, preventing dangerous low-lubrication running scenarios.
- Heavy-Duty Power Trim: Lifts the bow out of the water cleanly, drastically reducing hull friction during high-speed tournament sprints.
- Clean Four-Stroke Combustion: Eliminates messy two-stroke oil reservoirs, keeping your bilge completely clean while meeting strict clean water standards.

Why Choose Mercury 400CL

This exact counter-rotating 20-inch drive acts strictly as the port-side companion in a twin-engine array. You cannot run it as a standalone single engine. Proper setup requires exact mercury outboards digital throttle syncing across both motors.

- Measure your twin-engine transom bracket to confirm a strict 20-inch shaft requirement.
- Link the DTS module to your master binnacle to synchronize shift commands perfectly.
- Navigate restricted coastal fisheries legally utilizing advanced four-stroke combustion.

Ideal Application and Vessel Fitment

This 400-horsepower counter-rotating V10 is engineered strictly for twin-engine high-performance bay boats, low-profile center consoles, and tournament sport hulls demanding a 20-inch shaft. Operating on the port side, it actively cancels the massive starboard propeller torque to keep the hull tracking straight at 70 mph. It thrives in high-speed coastal tournament environments where balancing thrust, managing heavy fuel payloads, and achieving maximum top-end velocity require a synchronized, high-horsepower multi-engine approach.

Warranty, Support and Maintenance

Authorized recreational operation receives a 3-Year Limited Warranty alongside a 3-Year Corrosion Warranty. Registered commercial applications fall under a strict 1-Year Limited Warranty with zero corrosion coverage applied to the block. Scheduled maintenance requires replacing gearcase lubricants and changing oil filters at manual-specified intervals. Always save all physical service records. Your engine serial number acts as the only way to source exact genuine replacement parts. Mulmotor provides product-information support before purchase and assistance with order-related questions.