Let them try and catch you
Take the lead and never look back with the Mercury Racing 300R outboard. Featuring a rock-solid 15-inch HD Conventional MidSection (HD CMS), this adrenaline-pumping V8 powerhouse brings modern R-Series four-stroke technology to high-performance sport, flat sand bass boats. Whether you’re replacing a high-output two-stroke or building your new dream machine, experience the ultimate fusion of breathtaking speed and control.
Trimmed Down. Amped Up.
With a proven offshore pedigree, the HD CMS is built to exceed the most extreme boating demands. Heavy-duty forged transom brackets and a robust single-ram trim system with remote pump keep you running at the highest speeds through the most challenging conditions.
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Dialed In for Peak Power and Precision
Refined for Bold New Applications
Smaller footprint, same racing DNA—now available for boats that demand agility without sacrificing performance.
- Off shore racing
- High-performance sports boats
- High-Performance Bass Fishing
- Competition Drag Racing
Leveraging proven technology with seamless compatibility
Choose Your Configuration
Gearcase, control and steering options – plus the expertise of the Mercury Racing team – allow you to configure your 300R outboard for near-custom performance.
Versatile Steering Setup
Choose from hydraulic or power steering, with optional rear tie-bar mounting plates and side steering brackets.
Premium Controls
Digital Throttle & Shift - smooth, effortless shifting and lightning-fast throttle response. Mechanical - full-feel controls for those who prefer traditional feedback and response.
Gearcase Options
Engineered for versatility, the 300R features two gearcase options tailored for specialized performance.
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FACTS & FIGURES
Full Throttle RPM
5800
6400
RATED HP
300
CYLINDERS
V8
DISPLACEMENT
4.6 L
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Product Details
|
|
300 |
|---|---|
| SHAFT LENGTH | S: 15" / 381mm |
| FULL THROTTLE RPM | 5800-6400 RPM |
| IDLE RPM | 600 RPM |
| MOUNTS | Solid Upper and Solid One-Piece Lower Mounts |
| TRIM SYSTEM | Single Ram Trim and Tilt, Remote Pump |
| MAX TRIM RANGE | 20° (-5.3° to +14.7° on a 14° Transom) |
| MAX TILT RANGE | 72° |
| LIFT RANGE (MM) | N/A |
| TROLL CONTROL (RPM) | 550-1000RPM |
| MID SECTION | Heavy Duty Short Mid Section with Solid Mounts; Remote Trim Pump |
| ENGINE TYPE | V8 (32-valve, DOHC), Naturally Aspirated Four Stroke |
| WARRANTY | 3-Year Limited (Up to 5 Years Mercury Product Protection Available) |
| CORROSION WARRANTY | 3 Year Limited |
| RATED HP | 300 HP |
| RATED HP (KW) | 224 kW |
| BORE & STROKE (IN) | 3.62 x 3.39" |
| BORE & STROKE (MM) | 92 x 86mm |
| CYLINDERS / ENGINE CONFIGURATION | V8 [64 degree] with Dual Overhead Cam [DOHC] and 32-valves |
| DISPLACEMENT (L) | 4.6L |
| DISPLACEMENT (CID) | 279 CID |
| INDUCTION SYSTEM | Custom Racing Short-Runner Intake Manifold |
| COOLING SYSTEM | Water-cooled with thermostat |
| FUEL REQUIREMENT | Unleaded Regular 87 Octane Minimum (R+M/2) or 95 RON, 10% Ethanol Maximum |
| FUEL SYSTEM | Electronic Fuel Injection (EFI) Computer Controlled with Advanced Range Optimization |
| IGNITION SYSTEM | SmartCraft PCM 112 Digital Inductive |
| ENGINE MANAGEMENT SYSTEM | SmartCraft PCM 112 with SmartCraft Engine Guardian |
| CHARGING SYSTEM | 85-amp (1071 Watt) with Idle Charge |
| CHARGING (AMP) | 85 amp |
| CHARGING (WATT) | 1071 watt |
| IDLE CHARGE | Yes |
| STARTING | Electric Start with SmartStart Protection |
| EXHAUST SYSTEM | Through prop |
| LUBRICATION SYSTEM | Integrated wet sump |
| OIL REQUIREMENT | Mercury Racing MRX 10w-30 Full Synthetic Recommended NMMA Certified FCW SAE 10W-30 |
| OIL CAPACITY (LITERS) | 6.6 Liters |
| OIL CAPACITY (QUARTS) | 7.0 Quarts |
| CARB STAR RATING | 3-Star |
| MINIMUM CENTERLINE MOUNTING DISTANCE (IN) | 26" |
| STEERING | Hydraulic or Power Compatible with side-steering and aft tie bars |
| STEERING ANGLE | +/- 30 degress |
| JPO OPTION | No |
| THROTTLE & SHIFT CONTROLS | Mechanical or Digital Throttle & Shift (DTS) |
| GEARCASE | Torque Master Sport Master |
| GEAR RATIO | Torque Master: 1.75 Sport Master: 1.60 or 1.75 |
| SKEG | Torque Master: Cambered Sport Master: Cambered or Straight |
| TIE BAR BRACKET OPTION | Yes |
| GEAR SHIFT | F-N-R |
| OVERDRIVE RATIO | N/A |
| OVERALL DRIVE RATIO | 1.75 |
| Dry Weight (LBS) | 545 |
| Dry Weight (KGS) | 247 |
The Art of Speed
Mercury Racing Propellers offer the ultimate in performance and durability. Our propeller artisans handcraft each prop into precision tuned works of art.
Propellers- 500R
- 400R
- 300R
- 250R
- 200R
- 150R
- 60R View R-Series
Experience the future of luxury from the most advanced high-performance outboard on the water.
Rise above with the 400R – where extraordinary power meets exceptional drivability.
A fusion of breathtaking speed and control, the 300R is pure adrenaline-pumping freedom.
The stunning 250R elevates high performance on single-engine bass and sport boats.
Sophisticated power and digital controls for an exceptionally comfortable high-speed experience.
A lightweight, exhilarating power plant for those who test the limits in midsized high-performance boats.
Unleash your potential with the 60R, crafted for serious flats anglers who demand the best.
- Dual Cal 1550/1350
- Dual Cal 1350/1100
- 1100
- 700 SCI
- 600 SCI
- 565
- 520 View Sterndrives
Unshakeable strength. Unbelievable speeds. Our most powerful sterndrive engine outmuscles all challengers.
Two selectable performance calibrations ensure you maximize your thrills based on available fuel.
With heart-pumping power and monumental torque, the 1100 delivers a purely exhilarating experience.
A compact, rugged, supercharged performance machine – the absolute formula for power.
With legendary drive, the 600 SCi shines on high-performance, single-engine boats.
A flawless blend of big-block power and effortless digital control that never fails to impress.
Hand-crafted with precision, this compact powerhouse cranks out 520hp of back-in-your-seat performance.
- ROS
- APX
- Sterndrive
On the challenging waters of offshore powerboat racing, nothing can match the strength of the ROS series.
APX engines dominate closed-course powerboat competition with the most advanced four-stroke racing technology.
When the only option is winning, offshore racers turn to Mercury Racing sterndrive competition engines.
- Profile
- Precision
- Cases & Covers
- Prop Hub Kits
Profile Series props are cast to your specs then expertly tuned and hand-balanced by experienced craftsmen.
Precision Series props are sculpted to perfection using 5-axis CNC technology.
The finest art deserves the best protection, and your Mercury Racing prop is no different.
From engine-specific to rugged, high-speed options, Mercury Racing hubs unlock absolute performance.
- Digital Zero Effort Controls
- Joystick Piloting
- Performance Active Trim
- Integrated Transom System
- X-Haust Noise Reducer
- K-Plane Trim Tabs
- DTS Perfomance Pedal
Experience total command from premium digital controls designed for smooth, drive-by-wire precision.
Dock and maneuver with ease thanks to precision-guided 360-degree handling.
Digitally controlled trim automatically adjusts to ensure the most efficient, smooth ride.
Made for Bravo One XR® sterndrives, with integral power steering cylinders for a clean, pleasing connection.
Bring your high-performance sterndrive in compliance with regional noise regulations.
K-Plane® trim tabs maintain instantly responsive performance under the most punishing conditions.
A new throttle input sensor is roughly 20% the size of the outgoing pedal’s sensor, reducing packaging space and simplifying mounting in tight cockpits.
- Racing Lubricants
Run at the redline with premium lubricants formulated to protect high-intensity engines regularly pushed to extremes.
In a world that sets limits, Mercury Racing sets you free. We craft the most advanced high-performance marine propulsion systems on the water, empowering you to live life at the extreme.
It began with an unquenchable desire to win. With roots in performance boat racing, we’ve spent more than five decades perfecting the art of speed while redefining what’s possible on the water.
Whether you want technical advice to unlock a new level of speed or you need routine service, Mercury Racing stands behind you with expertise and support.
The QC4 Factory Refresh Program is a chance to turn back the clock by having the same team of master technicians who originally built your engine restore it to factory-fresh condition.
- R-Series Outboard
- Sterndrive
- Competition
- 500R
- 400R
- 300R
- 250R
- 200R
- 150R
- 60R
- Dual Cal 1550/1350
- Dual Cal 1350/1100
- 1100
- 700 SCI
- 600 SCI
- 565
- 520
- ROS
- APX
- Sterndrive
- Propellers
- Controls & Rigging
- Oils & Lubes
- Profile Series
- Precision Series
- Cases & Covers
- Prop Hub Kits
- Digital Zero Effort Controls
- Joystick Piloting
- Performance Active Trim
- Integrated Transom System
- X-Haust Noise Reducer
- K-Plane Trim Tabs
- DTS Performance Pedal
- Racing Lubricants
-
Events
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- Collaborations About Mercury Racing Our Heritage