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Mercury
Twin Mercury 300R
$34,000.00$35,000.00Save $1,000.00
High-performance racing-derived Mercury Racing 300R four-stroke outboard engines designed for advanced acceleration, top speed and reliability. Great for performance boats, offshore rigs and serious recreational use in twin setups
Horsepower
300 HP
Fuel Type
gasoline
Year
2023
Hours
127
Displacement
4.6L
Stroke
4-stroke
Rated Output
224 kW / 300mph
Rated Speed
6400rpm
In Stock (1 available)
Free shipping on orders over $500
90-day warranty included
Description
Buy used Twin Mercury Racing 300R outboards or explore new engines for sale built for elite marine performance and high-output offshore power. The Twin Mercury Racing 300R setup is a premium option for buyers searching for high-performance outboard engines, replacement marine power systems, and advanced propulsion solutions. Designed for speed, acceleration, and dependable operation, these outboards deliver exceptional performance for serious boating applications.
The Twin Mercury Racing 300R package is engineered to provide powerful acceleration, responsive handling, and smooth high-speed operation. Built for performance-focused vessels, this setup delivers strong power output and dependable marine capability across demanding offshore conditions.
Configured with 20-inch shaft lengths and equipped with 1.75 Sport Master lower units, these outboards are designed to maximize efficiency, improve water control, and support stable performance at higher operating speeds. The advanced lower unit configuration enhances handling and overall propulsion performance.
Integrated Digital Throttle and Shift (DTS) technology delivers smooth control, responsive operation, and refined engine management. Combined with IMCO steering, the setup provides improved precision and confident handling during high-performance boating conditions.
With approximately 127 operating hours, these Mercury Racing 300R outboards remain in excellent operating condition and continue to deliver premium marine performance. Their advanced engineering and performance-focused design make them a preferred solution for offshore and high-speed marine applications.
Ideal for center consoles, offshore boats, performance hulls, and custom marine builds, the Twin Mercury Racing 300R package delivers a powerful combination of speed, control, and long-term marine reliability.
Key Features:
• Twin Mercury Racing 300R outboard engines
• High-performance offshore marine platform
• 20-inch shaft configuration
• 1.75 Sport Master lower units
• Digital Throttle and Shift (DTS) system
• IMCO steering integration
• Approximate 127 operating hours
• Strong acceleration and high-speed capability
• Smooth and responsive operation
• Built for premium marine performance
Specifications
SKUM0184
BrandMercury
CategoryOutboard Engines
ConditionUsed
Horsepower300 HP
Fuel Typegasoline
Year2023
Displacement4.6L
No. of Cylinders8 cylinders
Stroke4-stroke
Shaft Length20
Weight1024.00 lbs
Hours127
Rated Output224 kW / 300mph
Rated Speed6400rpm
Cylinder Bore x Stroke92 mm × 86 mm / 3.62 in × 3.39 in
Combustion System4-stroke, spark-ignited, electronic fuel injection (EFI)
AspirationNatural
Alternator150- amp
Dry Weight229 kg / 505 lbs
ControlsDigital Throttle & Shift (DTS)
Frequently Asked Questions
What is the Mercury 300R outboard?
The 300R is a performance-tuned V8 four-stroke outboard motor from Mercury Racing designed for high-speed sport boats, offshore applications, and competition use. It blends race-derived technology with four-stroke reliability for powerful acceleration and top-end performance.
What does “300R” mean?
300R” indicates the 300 horsepower rating as part of Mercury Racing’s R-Series performance lineup — an engine meant for aggressive power and precision handling on demanding boats.
How much power does it produce?
The 300R produces approximately 300 HP (224 kW), giving strong thrust for performance hulls and larger boats.
What type of engine is inside a 300R?
It uses a 4.6 L V8 naturally aspirated four-stroke engine with dual overhead cams (DOHC) and 32 valves for responsive power and high-rpm performance.
What is the recommended full-throttle RPM range?
The wide-open throttle operating range is about 5,800 – 6,400 rpm, where the engine delivers its best power and efficiency.
What fuel does the 300R require?
It runs on unleaded gasoline with at least 87 octane (R+M/2), or 90 RON, with up to 10 % ethanol (E10) allowed — regular fuel availability helps reduce operating cost.
What type of fuel system does it use?
The 300R features computer-controlled Electronic Fuel Injection (EFI) with Advanced Range Optimization for precise fuel delivery and better throttle response.
Does the engine have modern throttle and shift controls?
Yes — the 300R supports Digital Throttle & Shift (DTS) for smooth, precise electronic control, or mechanical controls for traditional feedback.
What shaft lengths are available?
The 300R is available in 20″, 25″, or 30″ shafts so it can be matched to different boats and transom heights.
Can the 300R be installed in a twin configuration?
Yes — many performance boats use twin 300R engines for more total power, balanced thrust, and redundancy, though installation, rigging, and controls should be professionally engineered for safety and performance.
Does the 300R have power steering options?
Yes — it can be paired with hydraulic or power steering, and optional tie-bar or side-bracket mounts for tailored steering response.
What are the gearcase options?
There are multiple gearcases — Torque Master for torque-focused performance and Sport Master for balanced speed and efficiency — with different gear ratios.
What kind of cooling and lubrication does it use?
The 300R uses a water-cooled system with thermostat control and an integrated wet sump lubrication system to handle performance demands.
What’s required for maintenance on a 300R?
Engine oil and filter changes Lower-unit (gearcase) oil changes Water pump/impeller check Fuel and air filter service Corrosion protection and flushing after saltwater use
Is the 300R suitable for saltwater use?
Yes — with appropriate corrosion protection and post-use flushing, it can be used safely in saltwater environments. Modern finishes and alloys help resist corrosion.
Is the 300R reliable for long-term use?
When properly maintained and used within appropriate operating ranges, the 300R offers robust performance and durability, drawing on Mercury Racing’s proven four-stroke technology. Regular service and quality fuel/oil help maintain reliability.
Can I tune or customize a 300R for racing or performance?
Yes — configurations (midsection, gearcase, controls, steering) are customizable, and many owners use aftermarket props and performance rigs. Professional setup and expert rigging are recommended for safety and optimal results.
