FourStroke 2.5-20 HP

Introducing the Mercury FourStroke. Put amazing power in the palm of your hand. These compact outboard motors take you to the fun, the fish, or whatever floats your boat – quickly and reliably. Enjoy quick acceleration to go with exhilarating speed. Easy to install and operate, with reliable starting, low vibration, and instant throttle response. It’s worry-free boating at its best.
Built to deliver the type of power, thrust, and control that wider, heavier boats require. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.
Multiple trim positions to enhance performance and enable shallow-water operation. Through-prop exhaust makes it extra quiet.
Mercury 15 and 20hp FourStroke outboards are designed to improve every minute of your time on the water. The tiller can be adjusted for steering with either hand, adding convenience, while battery-free electronic fuel injection (EFI) and a twin-cylinder powerhead deliver reliability, easy starts, optimized fuel efficiency and outstanding power.

Norfolk Marine OUTBOARDS

FOURSTROKE TECHNOLOGY AND MERCURY

Always moving forward. With boater-driven innovations and technologies. Like the world’s first multi-function tiller handle. And a total commitment to corrosion protection, utilizing hard-coat anodizing and a superior multi-step paint process. Mercury FourStroke engines have consistently set the bar for clean, quiet performance and low fuel consumption. Plus, no one has more models to fit your needs.

Norfolk Marine OUTBOARDS

FourStroke 2.5-20 HP Specs

  • 2.5 HP

    Weighing in at just 38 pounds, this compact, reliable motor is a great choice for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 2.5 / 1.9
    Engine type 1 cylinder
    Displacement (CID/CC) 5.2 / 85
    Full throttle RPM 4500-5500
    Fuel induction system 2-valve pushrod (overhead valve)
    Recommended fuel 87 octane compatible (up to 10% ethanol)
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Over-rev
    Starting Manual
    Steering Tiller with 360° turning
    Shaft length 15″ / 381 mm
    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 41 lbs / 18 kg
    CARB star rating 3
    Bore and stroke 2.16 x 1.42″ / 55 x 36 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N
    Gearcase options Standard
    Trim system 4 position
    Trim positions 4
    Exhaust system Above prop
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Color Phantom Black
  • 3.5 HP

    Delivers lightweight, portable power and thrust for exact operation. Perfect for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 3.5 / 2.6
    Engine type 1 cylinder
    Displacement (CID/CC) 5.2 / 85
    Full throttle RPM 5000-6000
    Fuel induction system 2-valve pushrod (overhead valve)
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Over-rev
    Starting Manual
    Steering Tiller with 360° turning
    Shaft length 15″ / 381 mm

    20″ / 508 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 41 lbs / 18 kg
    CARB star rating 3
    Bore and stroke 2.16 x 1.42″ / 55 x 36 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N
    Gearcase options Standard
    Trim system 4 position
    Trim positions 4
    Exhaust system Above prop
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Color Phantom Black
  • 4 HP

    This lightweight motor features through-prop exhaust for extra-quiet operation. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 4 / 2.9
    Engine type 1 cylinder
    Displacement (CID/CC) 7.5 / 123
    Full throttle RPM 4500-5500
    Fuel induction system 2-valve pushrod (overhead valve)
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Manual
    Steering Tiller
    Shaft length 15″ / 381 mm

    20″ / 508 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 57 lbs / 26 kg
    CARB star rating 3
    Bore and stroke 2.32 x 1.77″ / 59 x 45 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Optional fuel tank (gal / L) 3.2 / 12
    Color Phantom Black
  • 5 HP Sail Power

    Engineered to meet the unique needs of sailboat enthusiasts. Also great for aluminum tiller, inflatable soft hull, jon, and utility boats.

    HP / kW 5 / 3.7
    Engine type 1 cylinder
    Displacement (CID/CC) 7.5 / 123
    Full throttle RPM 4500-5500
    Fuel induction system 2-valve pushrod (overhead valve)
    Alternator amp / Watt 4 amp / 50 watt lighting and charging
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Manual
    Steering Tiller
    Shaft length 20″ / 508 mm
    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 59 lbs / 27 kg
    CARB star rating 3
    Bore and stroke 2.32 x 1.77″ / 59 x 45 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Sail Power
    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Optional fuel tank (gal / L) 3.2 / 12
    Color Phantom Black
  • 5 HP

    Multiple trim positions to enhance performance and enable shallow-water operation. Through-prop exhaust makes it extra quiet. Lightweight: just 57 pounds. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 5 / 3.7
    Engine type 1 cylinder
    Displacement (CID/CC) 7.5 / 123
    Full throttle RPM 4500-5500
    Fuel induction system 2-valve pushrod (overhead valve)
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Manual
    Steering Tiller
    Shaft length 15″ / 381 mm

    25″ / 635 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 57 lbs / 26 kg
    CARB star rating 3
    Bore and stroke 2.32 x 1.77″ / 59 x 45 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Optional fuel tank (gal / L) 3.2 / 12
    Color Phantom Black
  • 6 HP

    Feature integral fuel tanks with an external fuel-shutoff valve. For extended range, they can also be connected to a remote fuel tank. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 6 / 4.4
    Engine type 1 cylinder
    Displacement (CID/CC) 7.5 / 123
    Full throttle RPM 5000-6000
    Fuel induction system 2-valve pushrod (overhead valve)
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Manual
    Steering Tiller
    Shaft length 15″ / 381 mm

    20″ / 508 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 57 lbs / 26 kg
    CARB star rating 3
    Bore and stroke 2.32 x 1.77″ / 59 x 45 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Integrated fuel tank (gal / L) 0.3 / 1.1
    Optional fuel tank (gal / L) 3.2 / 12
    Color Phantom Black
  • 8 HP

    Enhancements include simplified starting procedure, faster warmup, and better idle run quality. Lightweight: just 84 pounds. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 8 / 5.9
    Engine type Inline 2
    Displacement (CID/CC) 12.8 / 208
    Full throttle RPM 5000-6000
    Fuel induction system 2 valves per cylinder, single overhead cam (SOHC)
    Alternator amp / Watt 6 amp / 76 watt
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Electric

    Manual

    Steering Tiller
    Shaft length 15″ / 381 mm

    20″ / 508 mm

    Gearcase ratio 2.08:1
    Dry weight *Lightest model available 84 lbs / 38 kg
    CARB star rating 3
    Bore and stroke 2.16 x 1.73″ / 55 x 44 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim positions Ratcheting
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Remote fuel tank standard (gal / L) 3.2 / 12
    Color Phantom Black
  • 9.9 HP

    Built to deliver the type of power, thrust, and control that wider, heavier boats require. Great for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 9.9 / 7.3
    Engine type Inline 2
    Displacement (CID/CC) 12.8 / 208
    Full throttle RPM 5000-6000
    Fuel induction system 2 valves per cylinder, single overhead cam (SOHC)
    Alternator amp / Watt 6 amp / 76 watt
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil Mercury FourStroke Oil 10W-30
    Engine protection operator warning system Low oil pressure

    Over-rev

    Starting Electric

    Manual

    Steering Remote

    Tiller

    Shaft length 15″ / 381 mm

    20″ / 508 mm

    25″ / 635 mm (CT model)

    Gearcase ratio 2.08:1 or 2.42:1 (CT model)
    Dry weight *Lightest model available 84 lbs / 38 kg
    CARB star rating 3
    Bore and stroke 2.16 x 1.73″ / 55 x 44 mm
    Ignition CDI w/electronic spark advance
    Fuel system Carbureted
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Command Thrust (CT)

    Standard

    Trim system Power Tilt (CT model)
    Trim positions Ratcheting
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Remote fuel tank standard (gal / L) 3.2 / 12
    Color Phantom Black
  • 15 EFI

    Always moving forward. With boater-driven innovations and technologies. Like the world's first multi-function tiller handle. And a total commitment to corrosion protection, utilizing hard-coat anodizing and a superior multi-step paint process. Mercury FourStroke engines have consistently set the bar for clean, quiet performance and low fuel consumption. Plus, no one has more models to fit your needs.

    HP / kW 15 / 11.1
    Engine type Inline 2
    Displacement (CID/CC) 20.3 / 333
    Full throttle RPM 5700 – 6200
    Fuel induction system 2 valves per cylinder, single overhead cam (SOHC)
    Alternator amp / Watt 12/145 electric
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil 25W-40 Synthetic Blend

    Mercury FC-W 10W-30 4-Stroke Marine Oil

    Engine protection operator warning system Low oil pressure

    Low water pressure

    Over-rev

    Overheat

    Sensor failure

    Starting Electric

    Manual

    Steering Remote

    Tiller

    Shaft length 15″ / 381 mm

    20″ / 508 mm

    25″ / 635 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 99 lbs / 45 kg
    CARB star rating 3
    Bore and stroke 2.40 x 2.24″ / 61 x 57 mm
    Ignition CDI w/electronic spark advance
    Fuel system Electronic Fuel Injection (EFI)
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim system Manual

    Power Tilt

    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Remote fuel tank (optional) Yes
    Remote fuel tank standard (gal / L) 3.2 / 12
    Color Phantom Black
  • 20 EFI

    Ultra-lightweight (just 99 pounds) and reliable, with little vibration. Innovative tiller lets you lock the tiller at 73 degrees – great for fishing and trailering. Perfect for aluminum tiller, inflatable soft hull, jon, utility, and sail boats.

    HP / kW 20 / 14.7
    Engine type Inline 2
    Displacement (CID/CC) 20.3 / 333
    Full throttle RPM 5700 – 6200
    Fuel induction system 2 valves per cylinder, single overhead cam (SOHC)
    Alternator amp / Watt 12/145 electric
    Recommended fuel 87 octane / up to 10% ethanol
    Recommended oil 25W-40 Synthetic Blend

    Mercury FC-W 10W-30 4-Stroke Marine Oil

    Engine protection operator warning system Low oil pressure

    Low water pressure

    Over-rev

    Overheat

    Sensor failure

    Starting Electric

    Manual

    Steering Remote

    Tiller

    Shaft length 15″ / 381 mm

    20″ / 508 mm

    Gearcase ratio 2.15:1
    Dry weight *Lightest model available 99 lbs / 45 kg
    CARB star rating 3
    Bore and stroke 2.40 x 2.24″ / 61 x 57 mm
    Ignition CDI w/electronic spark advance
    Fuel system Electronic Fuel Injection (EFI)
    Cooling system Water-cooled with thermostat
    Gear shift F-N-R
    Gearcase options Standard
    Trim system Manual

    Power Tilt

    Trim positions 6
    Exhaust system Through prop
    Shallow water drive Yes
    Shallow water trim range (degrees) 16
    Remote fuel tank (optional) Yes
    Remote fuel tank standard (gal / L) 3.2 / 12
    Color Phantom Black

Interested In A FourStroke 2.5-20 HP?

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