Mercury 400CXXL 400HP Outboard – 30in Shaft, Counter Rotation, DTS

Description

Install the counter-rotating, 30-inch Mercury 400CXXL to resolve severe propeller ventilation on custom high-transom offshore hulls. The naturally aspirated 5.7-liter V10 forces immediate acceleration, pushing heavily loaded multi-engine center consoles over aggressive ocean swells. Taping your transom verifies this 30 inch shaft mercury outboard motor places the water intakes deep enough for safe operation.

Eradicate mechanical vibration that ruins passenger comfort by relying on the Advanced MidSection to isolate the powerhead completely. Heavy-duty elastomer mounts trap all mechanical shaking before it reaches the hull. Mercury casts the 320 kg assembly using specialized low-copper alloys. This physical barrier stops rapid metal degradation when repowering luxury multi-engine boats in high-salinity environments.

Key Features of Mercury 400CXXL

• Advanced MidSection (AMS): Isolates the powerhead using heavy-duty elastomer mounts, eliminating physical engine vibration at the steering console completely.
• 30-Inch XXL Shaft: Reaches deep below heavily modified offshore transoms, keeping the propeller fully engaged in clean undisturbed water.
• Counter-Rotating Gears: Balances propeller torque against a standard rotation engine, forcing massive offshore hulls to track perfectly straight underway.
• Digital Throttle and Shift: Eliminates mechanical cable friction completely, providing silky smooth gear engagement and exact electronic RPM control.
• 150-Amp Output Alternator: Outputs massive charging power, keeping demanding radar systems and heavy-duty livewell pumps fully powered offshore.
• Integrated Power Steering: Provides electro-hydraulic mechanical assist, delivering sports-car-like handling and zero steering fatigue during long offshore runs.
• Through-Prop Exhaust Hub: Buries loud V10 engine noise and raw combustion fumes deep below the ocean surface for a quieter ride.
• Top-Cowl Service Door: Provides direct access to the 9.5L oil dipstick, simplifying routine fluid checks without removing the heavy engine cover.
• 2.08:1 Gearcase Ratio: Transfers massive V10 torque to the propeller shaft securely, turning large diameter props without slipping.
• Naturally Aspirated V10: Eliminates complex supercharger piping entirely, reducing mechanical failure points when operating miles from the marina.

Why Choose Mercury 400CXXL

You select this counter-rotating 30-inch motor specifically to complete a twin or triple engine array on massive offshore hulls. Substituting a 25-inch model will cause catastrophic water pump starvation. Upgrading your mercury digital throttle network is required for multi-engine communication.

• Confirm a 30-inch vertical drop from the mounting bracket to the keel line.
• Network the DTS module securely to your master helm command center.
• Avoid heavy smoke and oil slicks using advanced V10 four-stroke internal lubrication.

Ideal Application and Vessel Fitment

Engineered for massive triple-engine center consoles, custom offshore catamarans, and luxury yacht tenders, this 30-inch shaft configuration reaches deep below highly elevated transoms to find clean water. Running this 30 inch shaft mercury outboard motor on the port side guarantees absolute tracking stability through aggressive ocean chop. The Advanced MidSection isolates all mechanical harshness, making it the definitive choice for high-end multi-engine vessels where passenger comfort is paramount.

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. For product details and order support, Mulmotor offers assistance before your purchase is placed.