Mercury FourStroke 25 HP EFI Outboard Motor 2024

Mercury 25 HP EFI 2024: Three Cylinders, No Battery Required

The 2024 Mercury 25 HP EFI FourStroke combines a 500cc three-cylinder with battery-free EFI — full electronic fuel injection that starts instantly on pull-start models with no battery installed. Triple-cylinder balance runs smoother than any twin, the multi-function tiller keeps control one-handed, and F-N-R gearing plus manual/electric start, tiller/remote, and power trim options rig it for any hull. With no-spill oil changes and a maintenance-free valve train, it’s a class leader in the 25HP outboard class.

Key Features (2024)

• Battery-free EFI — injection with zero battery requirement
• 500cc three-cylinder — triple smoothness
• Multi-function tiller; F-N-R; power trim options
• No-spill oil change; maintenance-free valve train

Specifications

• Engine: 3-cylinder four stroke, 500cc
• Horsepower: 25 HP
• Fuel Induction: Battery-free EFI
• Starting: Manual or Electric
• Gearshift: Forward-Neutral-Reverse
• Steering: Tiller or remote; power trim available
• Fuel: External tank, 87 octane
• Shaft: 15″ (S) / 20″ (L)

Benefits & Applications

Triple balance and injected reliability for 15–18 ft aluminum boats, skiffs, RIBs, pontoons, and workboats. Rivals: Suzuki DF25A 2024, Honda BF25 2024. Top tune: Mercury 30 HP EFI 2024.

Compare Model Years

See the 25 HP EFI 2025 and 25 HP EFI 2026, all Mercury Outboards, or the Mercury brand guide.

Frequently Asked Questions

Does the Mercury 25 EFI need a battery?

No — battery-free EFI runs the injection on pull-start models without one.

Why three cylinders?

Smoother idle, quieter cruise, and less vibration than twin-cylinder rivals.

Best boats?

15–18 ft aluminum boats, skiffs, RIBs, pontoons, and workboats.