Engine Information and Specifications

  •  25 hp EFI

    Engine Details

    Delivers consistent, easy starting, crisp throttle response, increased fuel economy, and outstanding overall performance. Great for aluminum tiller, aluminum console, jon, utility, and fish & ski boats.

    Specifications - 25 EFI

    HP / kW
    • 25 / 18.6
    Engine type
    • Inline 3
    Displacement (CID/CC)
    • 32.1 / 526
    Full throttle RPM
    • 5000-6000
    Fuel induction system
    • 2 valves per cylinder, single overhead cam (SOHC)
    Alternator amp / Watt
    • 15 amp / 186 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
    • Overheat
    • Sensor failure
    Starting
    • Electric (turn-key)
    • Manual
  •  20 EFI

    Engine Details

    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.

    Specifications - 20 EFI

    HP / kW
    • 20 / 14.7
    Engine type
    • Inline 2
    Displacement (CID/CC)
    • 20.3 / 333
    Full throttle RPM
    • 5700 - 6200
    Fuel induction system
    • Single Overhead Cam
    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
  •  15 EFI

    Engine Details

    Low weight and awesome torque get your boat on plane quicker and provide best-in-class acceleration to complement best-in-class top speed. A perfect match for aluminum tiller, soft-hull inflatable, jon / utlity, or sail boats.

    Specifications - 15 EFI

    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 compatible (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
    • Over-rev
    • Overheat
    • Sensor failure
    Starting
    • Electric
    • Manual
  •  9.9

    Engine Details

    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.

    Specifications - 9.9

    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
  •  8

    Engine Details

    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.

    Specifications - 8

    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
  •  6

    Engine Details

    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.

    Specifications - 6

    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
  •  5 Propane

    Engine Details

    Mercury’s all-new 5hp FourStroke Propane outboard provides more convenience and less hassle. With a large 123cc displacement, it offers best-in-class power by delivering a true 5 horsepower. Ideal for aluminum tiller, inflatable or jon / utility boats.

    Specifications - 5 Propane

    HP / kW
    • 5 / 3.7
    Engine type
    • 1 cylinder
    Displacement (CID/CC)
    • 7
    Displacement (L)
    • 7.5 / 123
    Full throttle RPM
    • 5000-6000
    Fuel induction system
    • 2-valve pushrod (overhead valve)
    Recommended oil
    • Mercury FourStroke Oil 10W-30
    Engine protection operator warning system
    • Low oil pressure
    • Over-rev
    Starting
    • Manual
    Steering
    • Tiller
  •  5

    Engine Details

    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.

    Specifications - 5

    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
  •  5 Propane Sail Power

    Engine Details

    Mercury’s all-new 5hp FourStroke Propane outboard provides more convenience and less hassle. Sail Power model is designed for sailboats and features an alternator and more thrust. Ideal for sailboats, but also a good fit for aluminum tiller, inflatable or jon / utility boats.

    Specifications - 5 Propane Sail Power

    HP / kW
    • 5 / 3.7
    Engine type
    • 1 cylinder
    Displacement (CID/CC)
    • 7.5 / 123
    Full throttle RPM
    • 5000-6000
    Fuel induction system
    • 2-valve pushrod (overhead valve)
    Alternator amp / Watt
    • 4 amp / 50 watt lighting and charging
    Recommended oil
    • Mercury FourStroke Oil 10W-30
    Engine protection operator warning system
    • Low oil pressure
    • Over-rev
    Starting
    • Manual
    Steering
    • Tiller
  •  4

    Engine Details

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

    Specifications - 4

    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
  •  3.5

    Engine Details

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

    Specifications - 3.5

    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
  •  2.5

    Engine Details

    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.

    Specifications - 2.5

    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
Announcing NEW Mercury 20hp & 15hp outboards

Announcing NEW Mercury 20hp & 15hp outboards

The ultimate boating experience comes standard. Mercury’s newest addition to its lineup of portable FourStroke outboard motors is designed and built to improve every aspect of your time on the water, from starting the engine to changing the oil and everything in between. Watch here

Award-winning tiller handle

Award-winning tiller handle

Mercury Marine's tiller handle assembly for the 15 and 20hp portable outboard motors won the 2018 award in the "Propulsion Parts" category at the annual International Boatbuilders' Exhibition & Conference (IBEX). This new tiller handle features several remarkable advancements to make the steering, shifting and throttle operation of portable outboards more intuitive, comfortable and responsive, and is the world's first portable outboard tiller that offers ambidextrous operation.

Reliability, Portability and Power with the convenience of Propane

Reliability, Portability and Power with the convenience of Propane

Mercury’s all-new 5hp FourStroke Propane outboard provides more convenience and less hassle. With a large 123cc displacement, it offers best-in-class power by delivering a true 5 horsepower. Sail Power model is designed for sailboats, and features an alternator and more thrust.

Get more details

Documents

Brochures
Brochures

Take a deeper dive into what makes Mercury outboards stand apart with detailed information on each motor and the features that make them unique.

https://www.mercurymarine.com/en/china/engines/outboard/fourstroke/25-25-hp/