UNMATCHED SPEED, ACCELERATION & EFFICIENCY
- Naturally aspirated, 4.6 Liter V-8; 44% higher displacement
- Dual overhead cam (quad cam) four valve design for unsurpassed
power and torque - Transient spark calibration increases torque 5-7% during hole
shot for unmatched acceleration - Advanced Range Optimization automatically adjusts fuel delivery
for up to 10% improvement in cruise-speed fuel efficiency - 87-octane (90 RON) pump fuel calibration and global emissions
compliance
SPORTS-CAR-LIKE DRIVABILITY AND HANDLING
- Tri-Ram midsection with high-durometer elastomer upper mount
and solid lower mounts for enhanced handling at higher speeds - Selected 300R models with the heavy-duty midsection feature
forged transom brackets with single ram power trim and remote
trim pump designed to endure the harsh offshore environment - The surface piercing Sport Master gearcase provides maximized
efficiency for boats capable of speeds in excess of 85 mph - Electronically-actuated throttle and shifting, compatible with
Mechanical or DTS remote controls
The new 250R and 300R outboards boast class-leading 4.6L displacement, resulting in 40% more bottom-end torque.
Mercury’s proprietary transient spark calibration, which boosts torque by as much as 7% during hole shot by optimizing spark timing and fueling, gets boats on plane quickly.
…all that displacement and power are delivered in a compact light weight package with 26-inch mounting centers, perfect for repower and multi-engine options.
RACE INSPIRED PERFORMANCE
Designed, developed and manufactured in-house, the naturally aspirated, 4.6L V-8 fourstroke engines share Mercury Racing’s venerable Quad Cam Four Valve (QC4) sterndrive DNA – complete with aluminum four-valve cylinder heads and dual overhead camshaft (DOHC) valve train. The four valve heads and DOHC valve train are integrated with Mercury’s proprietary V-8 cylinder block, packed with high performance hardware.
POWER
Dual overhead cam (quad cam) four valve design for enhanced power and durability
INTAKE
- Naturally aspirated, 4.6 Liter V8 engine
- 300 rated horsepower on 87 octane pump fuel
- 200 RPM higher operating range for greater top-end speeds.
- Racing exclusive intake cam profiles and short intake manifold runners for maximized power throughout the engine operating rpm band
MIDSECTIONS
- Tri-Ram midsection with high-durometer elastomer upper mount and solid lower mounts for enhanced handling at higher speeds
- Heavy duty midsection models come with solid mounts and robust, forged transom brackets with single ram power trim and remote trim pump designed to endure the harsh offshore environment
- Optional electro-hydraulic power steering for an exceptionally smooth and responsive driving experience
INTEGRATED REAR TIE-BAR
An integrated rear tie-bar mounting plate on selected H.D. Midsection models for enhanced stability on high speed multiple engine applications
GEARCASE OPTIONS
The surface piercing Sport Master, designed for boats capable of speeds in excess of 85 mph, features low-water pick-ups and a crescent leading-edge for maximized efficiency and speed
The Torque Master, designed to run partially surfaced, carries the load of heavier tournament bass boats and multi-species hulls while maximizing top speed and drivability
The 5.44” HD is designed for use on bay boats and multi engine performance center consoles where the application requires a more submerged gearcase
BOLD NEW STYLING
EASY MAINTENANCE
COLOR OPTIONS
Aggressively styled top cowl designates a new era of high performance outboard propulsion from Mercury Racing. Bold new, ultra-premium graphics with Devil Red accent panel screams performance.
Industry-exclusive Top Cowl Service Door simplifies routine maintenance with easy oil checks and oil fills without removing the cowl. Graphic, hour-based maintenance decals under the cowl for easy access to all regular powerhead maintenance points.
Maintenance-free valve-train for life of the engine.
An optional Graphite Grey accent panel is available as a kit. A paint-ready kit is also available to custom match the engine to the boat.
SPECIFICATIONS
| Horsepower | 250 HP | 300 HP | 300 HP |
| WOT RPM | 5600-6200 | 5800-6400 | 5800-6400 |
| Engine Type | V-8 [64 degree] with Dual Overhead Cam (DOHC and 32-valves) | V-8 [64 degree] with Dual Overhead Cam (DOHC and 32-valves) | V-8 [64 degree] with Dual Overhead Cam (DOHC and 32-valves) |
| Displacement | 4.6L (279 CID) | 4.6L (279 CID) | 4.6L (279 CID) |
| Induction System | Performance-Tuned Long-Runner Intake Manifold | Custom Racing Short-Runner Intake Manifold | Custom Racing Short-Runner Intake Manifold |
| Midsection Design | Tri-Ram Midsection with High-Durometer Upper Mount and Solid Lower Mounts | Tri-Ram Midsection with High-Durometer Upper Mount and Solid Lower Mounts | Heavy Duty Mid Section wtih Solid Mounts; Remote Trim System |
| Fuel Requirements | Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum | Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum | Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum |
| Charging System | 85-amp (1071 Watt) with Idle Charge | 85-amp (1071 Watt) with Idle Charge | 85-amp (1071 Watt) with Idle Charge |
| Starting | 4.6L (279 CID) | 4.6L (279 CID) | 4.6L (279 CID) |
| Starting | Electric Start with SmartStart Protection | Electric Start with SmartStart Protection | Electric Start with SmartStart Protection |
| Throttle and Shift Controls | Mechanical | Mechanical and Digital Throttle and Shift | Mechanical and Digital Throttle and Shift |
| Gearcase | Sport Master | Torque Master Sport Master | Sport Master 5.44″ H.D. |
| Gear Ratio | 1.75:1 | 1.75:1 | 1.75:1 |
| Warranty | 3-Year Limited | 3-Year Limited | 3-Year Limited |
| Dry Weight (lbs./kg)* | |||
| L – 20″ | 520 lbs / 236 kgs | 512 lbs / 232 kgs | 546 lbs / 247 kgs** |
| XL – 25″ | n/a | n/a | 556 lbs / 252 kgs** |
| XXL – 30″ | n/a | n/a | 566 lbs / 257 kgs** |
* Dry weight refers to base engine without liquids, battery cables, throttle/shift cables, bolt-on steering components, mounting hardware, or propeller/hub kits.
**300R HD weight inlcudes remote trim pump assembly