2025 Mercury Marine® FourStroke 300 hp Base
- Year 2025
- Make Mercury Marine®
- Model FourStroke 300 hp
2025 Mercury Marine® FourStroke 300 hp
Reliability, flexibility, power and efficiency – all within your reach. Backed by decades of marine power innovation and product leadership, Mercury V8 and V6 FourStroke outboards deliver legendary performance and forward-thinking technology. FourStroke outboards are built for any body of water and a wide variety of boats.
Features may include:
Adaptive Speed Control- Adaptive Speed Control maintains a desired rpm regardless of changes in load or conditions without adjustments to the throttle lever position – a first for the outboard industry.
- The V8 and V6 FourStroke engines are quieter and smoother than the leading competitor.
- The exclusive Top Cowl Service Door simplifies routine maintenance, letting you check or add engine oil without removing the top cowl. An hour-based maintenance schedule decal is located under the cowl, providing a quick overview of routine maintenance.
- When battery voltage is low, engines will automatically increase idle rpm to boost alternator output and charge batteries to the proper level, protecting batteries from draining while trolling and operating electronic devices.
- FourStroke models feature a robust alternator that delivers 20 amps net of charging power at idle and 30 amps total at wide-open throttle.
Engine
							Engine Type
							V-8
						
						
							Engine Power
							300 / 224
						
						
							Displacement
							279 CID (4.6 L)
						
						
							Throttle
							Full: 5200-6000 RPM
						
						
							Oil capacity
							7.0 Quarts  (6.6 Liters)
						
						
							Oil Type
							NMMA Certified FCW SAE 10W-30 | Lubrication system: Integrated wet sump
						
						
							Gear Ratio (Primary)
							1.75:1 | Shift: F-N-R
						
						
							Steering
							Hydraulic
						
						
							Emissions
							CARB star rating: 3
						
						
							Ignition
							SmartCraft PCM 112 Digital Inductive
						
						
							Bore
							3.6 in (92 mm)
						
						
							Stroke
							3.4 in (86 mm)
						
						
							Cooling
							Water-cooled with thermostat
						
						
							Exhaust
							Through prop
						
						Operational
							Operating Conditions
							Maximum Trim Range: 20° (-6° to 14°) | Maximum Tilt Range: 73° (-6° to 67°)
						
						Electric
							Alternator
							85-amp (1071 Watt) with Idle Charge
						
						
							Starter
							Electric Start with SmartStart Protection
						
						Fuel System
							Fuel System
							Air induction: Performance-Tuned Long-Runner Intake Manifold | Fuel induction system: Electronic Fuel Injection (EFI) Computer Controlled with Advanced Range Optimization
						
						
							Fuel Type
							Recommended: Unleaded Regular 87 Octane Mini- mum (R+M/2) or 90 RON 10% Ethanol Maximum
						
						Dimensions
							Length
							Shaft: 20" (508 mm) | 25" (635 mm)
						
						Weights
							Dry Weight
							Lightest model available: 527 lbs (239 kgs)
						
						Features
							Features
							MidSection: Conventional MidSection (CMS) | Engine protection operator warning system: SmartCraft Engine Guardian |  Controls: Remote Mechanical or Digital Throttle & Shift (DTS) | Cylinder Configuration: V-8 [64 degree] with Dual Overhead Cam [DOHC] and 32-valves | Trim system: Power trim and tilt | Compatible with SmartCraft digital technology: Yes | Counter Rotation: Available
						
					 
			