Engine Information and Specifications

  •  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
    • 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
  •  15 EFI

    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 / 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
  •  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

    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 Sail Power

    Engine Details

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

    Specifications - 5 Sail Power

    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
  •  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
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

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.

Owners Manuals

Owners Manuals

Need an Owner’s Manual for your Mercury engine to perform maintenance, replace parts or just learn more about your engine? Mercury has made it easy for you to purchase a printed copy or to download and print your own copy. To order a printed version of the Service Manual for your particular Mercury Outboard or MerCruiser Engine, click here.  

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.

Sorry, your browser is not supported

Please consider upgrading to a more up-to-date browser. The most popular browsers are Chrome, Edge, and Safari. Upgrading to the latest version of one of these will make the web safer, faster, and better looking.

(not recommended)


https://zmm.ca/en/us/engines/outboard/fourstroke/25-25hp/