2017 Mercury FourStroke 40 HP EFI - 20 in. Shaft

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FourStroke 40 HP EFI - 20 in. Shaft



Held to a Higher Standard

Enhanced fuel injection for boosted efficiency

  • Smooth and Strong Performance: A compact, single-overhead-cam design and long piston stroke give Mercury 40 - 60hp FourStroke outboards more low-end torque for excellent acceleration, even when pushing a heavy load. The high-displacement, long-stroke, four-cylinder, single-overhead cam design provides optimum power and a smooth ride with Command Thrust models.
  • The Big Tiller: The optional center-mounted Big Tiller offers optimal control. A longer tiller grip incorporates a convenient power trim switch, the shift lever is close at hand, and an optional digital troll control adjusts engine speed as low as 700 rpm in 10-rpm increments.
  • Turnkey starts / fuel efficiency: Mercury Electronic Fuel Injection (EFI) delivers reliable turnkey starts, improved fuel efficiency, instant throttle response and protection against low-quality-fuel problems.
  • Electrical support: An 18-amp high-output alternator keeps batteries charged and fishing electronics humming.
  • SpitFire and SpitFire Pontoon Propellers: The advanced design of the Mercury® Spitfire® aluminum propeller combines four aggressive blades with high rake angles and extra cup for tenacious holding and 25% quicker acceleration, with no loss in top speed compared to a three-blade Mercury Black Max® propeller of the same pitch. The advanced design of the Mercury Spitfire Pontoon four-blade aluminum propeller maximizes blow-out resistance, with extra blade area for outstanding hold in turns and extra thrust around the dock that pontoon boaters need and demand. The Spitfire Pontoon propeller is available for 40 - 60hp Command Thrust engines in 10-, 11- and 13-pitch sizes.
  • More Control, Hole Shot and Mid-Range Power: Increased thrust is delivered by a 2.33:1 gear ratio with 44% larger gears. The desmodromic shifting is ultra-smooth. A gearcase that sits deeper in the water, a bigger prop with 20% more blade surface, and lower gear ratio provide unmatched thrust, maneuverability and boat lift.
  • HP / kW: 40 / 30
  • Engine type: Inline 3
  • Displacement (CID/CC): 45.6 / 747
  • Full throttle RPM: 5500-6000
  • Fuel induction system: 2 valves per cylinder, single overhead cam (SOHC)
  • Alternator amp / Watt: 18 amp / 226 watt
  • Recommended fuel: 87% octane / up to 10% ethanol
  • Recommended oil: Mercury FourStroke 25W40 Marine Oil
  • Engine protection operator warning system: Low oil pressure, Over-rev, Overheat
  • Compatible with SmartCraft digital technology: Yes
  • Starting: Electric (turn-key)
  • Steering: Big Tiller Compatible, Remote, Tiller Kit
  • Shaft length: 20 in. / 508 mm
  • Gearcase ratio: 2.00:1
  • Dry weight *Lightest model available: 216 lb. / 98 kg
  • CARB star rating: 3
  • Bore and stroke: 2.56 x 2.95 in. / 65 x 75 mm
  • Ignition: ECM 70
  • Fuel system: Electronic Fuel Injection (EFI)
  • Cooling system: Water-cooled with thermostat
  • Gear shift: F-N-R
  • Gearcase options: Standard
  • Trim system: Gas assist, Power Tilt, Power Trim
  • Exhaust system: Through prop
  • Shallow water trim range (degrees): 20
  • Remote fuel tank (optional): Yes
  • Color: Phantom Black
Dry weight based on lightest model available.



Engine Type
Inline 3
Bore x Stroke
2.56 x 2.95 in. (65 x 75 mm)
45.6 cid (747 cc)
Electric (turn-key)


Shaft Length
20 in. (508 mm)
216 lb. (98 kg)


Trim Method
Gas assist, Power Tilt, Power Trim
Propshaft Horsepower
40 hp (30 kW)
Full Throttle Operating Range
5500-6000 rpm
Gear Ratio / Shift
2.00:1 / F-N-R
Fuel Induction
2 valves per cylinder, single overhead cam (SOHC)
18 amp / 226 watt
Water-cooled with thermostat
Big Tiller Compatible, Remote, Tiller Kit
3 Year Corrosion, 3 Year Limited

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