2025 Mercury Marine® FourStroke 300hp

2024 Mercury Marine® FourStroke 300 hp

3.4L V6 and 4.6L V8

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.

Smooth and Quiet

The V8 and V6 FourStroke engines are quieter and smoother than the leading competitor.

Easy to Maintain

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.

Industry-Exclusive Battery Management Technology

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.

Ample Charging Output

FourStroke models feature a robust alternator that delivers 20 amps net of charging power at idle and 30 amps total at wide-open throttle.