Tuned up with Mercury Racing components to deliver blistering speed, the V8 4.6L 300R outboard delivers crisp throttle response, thrilling top-end power and confident control, the perfect match for a wide variety of high-performance boats. The 300R midsection and gearcase options, tie-bar and steering choices allow the creation of a near-custom configuration to provide optimal performance and ease of installation for most applications, including re-power upgrades.
Highlights
4.6L V8: The 300R is part of the Mercury Racing V8 FourStroke outboard lineup, designed to be high-winding, rugged and reliable. It's loaded with advanced design elements and Mercury Racing technology to go quicker, faster and farther than previously imagined.Short Runner Intake: A short-runner intake manifold and high-lift intake camshaft designed specifically for the 300R combine to produce quick acceleration.Midsection Options: Three midsection choices designed for specific applications feature high-performance engine mounts to stabilize the 300R for enhanced high-speed handling. Mercury Racing Advanced MidSection (Racing AMS) features heavy-duty guide plates, Digital Throttle and Shift (DTS) control and Mercury electro-hydraulic power steering, and optional integrated rear tie-bar brackets and Joystick Piloting for Outboards (JPO). The durable Mercury Racing CMS for 20-inch models features the integral Tri-Ram trim system. The HD CMS features heavy-duty forged transom brackets and a robust single-ram trim system with a remote pump, and optional rear tie-bar mounting plates and side steering brackets. Both the CMS and HD CMS are available with DTS or mechanical controls and Mercury electro-hydraulic power steering.RPM Range: To maximize top speed and propping options the wide-open throttle (WOT) operating range is extended to 5800-6400 RPM.Key Features
Tie-Bar Option: An optional rear tie-bar bracket integral to the Racing AMS provides a strong, ultra-light mounting point for precision steering in ultra-high-speed applications. Select HD CMS models are available with optional rear tie-bar mounting plates and side steering brackets for high speed applications when using the Sport Master gearcase.Color Options: The Mercury Racing 300R with Racing Advanced MidSection (Racing AMS) is offered in legendary Mercury Phantom Black or Cold Fusion White, with silver AMS and gearcase. 300R CMS and HD CMS models are Phantom Black with a silver gearcase.Accent Panels: The standard Devil Eye Red cowl accent panel may be replaced with an optional upgrade to a Graphite Gray or Carbon Fiber panel.Switchable Exhaust: Advanced Sound Control (Racing AMS models with optional VesselView) toggles a dual muffler system between an ultra-quiet mode and a deep sport tone with a stirring growl on start-up.Go Farther Faster: To squeeze more power from less fuel, naturally aspirated Mercury Racing V8 outboards feature Advanced Range Optimization (ARO), a closed loop fuel-control system that utilizes electronic sensors to precisely adjust the fuel mixture for the best-possible efficiency at all speeds.Mercury Racing 300R is engineered to be reliable and durable. A rugged midsection is designed to handle all the high-performance abuse the water can dish out. Superior protection against corrosion begins with the industry’s lowest-copper aluminum alloy and exclusive, comprehensive finish treatments. These high-performance outboards are tested, tested and tested again – in the lab and on the water – in a never-ending quest to exceed the highest expectations.Specifications
Full Throttle: 5800-6400 RPMRated HP: 300 HPCylinders: V8Displacement: 4.6 LShaft Length: 20"Trim System: Standard or Heavy DutyMid Section: Standard, Heavy Duty or Racing AMSSkeg: Camber or StraightWarranty: 3-YearBore & Stroke: 3.6 x 3.4" (92 x 86 mm)Induction System: Custom Racing Short-Runner Intake ManifoldFuel Requirement: Unleaded Regular 87 Octane Minimum (R+M/2) Or 90 RON 10% Ethanol MaximumFuel System: Electronic Fuel Injection (EFI) Computer Controlled With Advanced Range OptimizationIgnition System: Digital InductiveCharging: 115 (Amp) (85 CMS)Idle Charge: YesStarting: Electric Start With SmartStart ProtectionOil Requirement: NMMA Certified FCW SAE 10W-30Jpo Option: N (CMS), Optional (AMS)Throttle & Shift Controls: DTS (AMS), DTS or Mechanical (CMS)Gearcase: Torque Master, Sport Master or 5.44 HDGear Ratio: 1.85 (Ams), 1.75:1 (Cms) Or 1.60:1 (CMS, AMS)Dry Weight: 512 lbsCarb Star Rating: 3Minimum Centerline Mounting Distance (In): 26Steering: Electro-Hydraulic Power SteeringTie Bar Option: Integrated (AMS), Bracket (CMS)Idle: 600 RPMMounts: Hard Rubber or SolidEngine Type: V-8 NA 4SLubrication System: Integrated Wet SumpGear Shift: F-N-REngine Management System: SmartCraft PCM 112Engine Protection System: SmartCraft Engine GuardianExhaust System: SelectableOil Capacity: 6.6LSteering Angle: + 30 / - 30 deg.
