Mercury 300CXL SeaPro AMS 300HP – Commercial AMS Counter Rotation

Mercury 300CXL SeaPro AMS 300HP V8

The Mercury 300CXL SeaPro AMS is a specialized 300HP commercial outboard featuring the Advanced MidSection (AMS) for unrelenting reliability and ride refinement in the United States maritime sector. Built on a 4.6L V8 32-valve DOHC architecture and weighing 600 lbs, this engine generates phenomenal displacement-driven torque for heavy-duty applications. This 25-inch extra-long shaft model is configured for counter-rotation, making it the appropriate port-side choice for commercial multi-engine vessels. Our reliable marine outboard engines provide the mechanical integrity and digital precision required for rigorous daily commercial tasks. Maximum operational performance for the Mercury 300HP SeaPro is calibrated within a focused 4800 to 5600 RPM band, prioritizing industrial-grade durability over top speed. The commercial-grade 1.75:1 gear ratio is specifically engineered to translate the V8 torque into steady hull planing under offshore payloads. Proudly manufactured in the USA, this corrosion-resistant marine engine incorporates SmartCraft Digital Throttle & Shift (DTS) and Advanced MidSection vibration isolation for the comfort required during long commercial shifts.

Technical Specifications of Mercury 300CXL SeaPro AMS

• The 4.6L V8 DOHC architecture delivers displacement and high-torque performance for heavy payload hauling and towing.
• Advanced MidSection (AMS) provides a cradle-mount system that virtually eliminates engine vibration and noise in the vessel’s cockpit.
• Counter rotation left-hand drive provides perfectly balanced steering and tracking in commercial dual or triple engine installations.
• SmartCraft Digital Throttle & Shift (DTS) eliminates mechanical cable friction for ultra-smooth gear engagement at the helm.
• A robust 85 Amp alternator with Idle Charge keeps heavy-duty commercial navigation and communication equipment fully powered.
• Integrated Electro-Hydraulic power steering offers hyper-responsive, precision control for large-scale offshore commercial vessels.

Advanced MidSection (AMS) Refinement

The SeaPro AMS series is defined by the Advanced MidSection, which isolates the powerhead from the transom using specialized mounts. This engineering provides a significant reduction in vibration, ensuring that commercial operators and crews enjoy a fatigue-free work environment during long transits in the American saltwater environment.

Commercial 1.75:1 Gearcase

The 1.75:1 SeaPro lower unit is built to tackle the heaviest commercial loads. By sitting deeper in the water and spinning a larger prop, it offers authority in rough water, pulling heavy barges or passenger vessels onto plane with ease and holding them there at efficient cruising speeds.

High-Output 85A Alternator

Equipped with an 85 Amp alternator featuring Idle Charge technology, this engine generates 1071 Watts of charging power. This helps support high-draw radar, commercial sonar, and safety lighting never drain the battery during long hours of idling or low-speed maneuvers in busy industrial harbors.

Mercury SeaPro Warranty

This 300HP SeaPro outboard is backed by Mercury’s dedicated commercial warranty program for American owners. This factory-level protection helps support long-term peace of mind and grants access to genuine parts through a vast nationwide marine dealer network, minimizing vessel downtime.

Maintenance & Longevity

Maintaining clean oil in the 7.0L integrated wet sump system is vital for preserving engine tolerances over thousands of operating hours. Always flush the cooling system with fresh water after every saltwater mission.Pro Tip from the Shop:Commercial SeaPro AMS units subject the mounts to constant stress; routinely inspect the Advanced MidSection bushings for wear and utilize the Top Cowl Service Door for daily fluids checks without removing the cowling.