Mercury FourStroke 90HP

Embrace Possibility.

Mercury FourStroke outboard motors are incredibly powerful and efficient and they feature a wide range of applications. Crafted for less weight and high displacement, they generate abundant torque and immediate power. And because they don’t have to work as hard as heavier engines or those with lower displacement, they make boats plane faster and accelerate better and they provide optimal fuel efficiency at cruising speed.

Engine Details

Made to provide outstanding acceleration and throttle response. Great for deck, inshore fishing, bass, aluminum tiller, aluminum console, runabout open bow, inflatable rigid hull, and fish & ski boats.
HP / kW
  • 90 / 67
Engine type
  • 8-valve single overhead cam (SOHC)
  • Inline 4
Displacement (L)
  • 2.1
Full throttle RPM
  • 5000-6000
Air induction
  • Performance-Tuned Scroll Intake Manifold
Fuel induction system
  • Computer Controlled Multi-Port Electronic Fuel Injection (EFI)
Alternator amp / Watt
  • 35 amp / 441 watt with water-cooled voltage regulator
Recommended fuel
  • Unleaded Regular 87 Octane Minimum (R+M/2) or 90 RON 10% Ethanol Maximum
Recommended oil
  • Mercury FourStroke Oil 10W-30
Engine protection operator warning system
  • SmartCraft Engine Guardian
Details
Compatible with SmartCraft digital technology
  • Yes
Starting
  • Smart Start Electric
Controls
  • Mechanical throttle & shift
Steering
  • Big Tiller Compatible
  • Dual cable mechanical
  • Hydraulic power steering
Shaft length
  • 20" / 508 mm
  • 25" / 635 mm
Gearcase ratio
  • 2.07:1 or 2.38:1 (CT model)
Dry weight *Lightest model available
  • 359 lbs / 163 kg; 363 lbs / 165 kg (CT model)
CARB star rating
  • 3
Bore and stroke
  • 3.5 x 3.2" / 90 x 81 mm
Ignition
  • SmartCraft ECM 70 Digital Inductive
Fuel system
  • Electronic Fuel Injection (EFI)
Cooling system
  • Water-cooled with thermostat
Gear shift
  • F-N-R
Gearcase options
  • Command Thrust
  • Standard
Trim system
  • Power Tilt
  • Power Trim
Exhaust system
  • Through prop
Shallow water trim range (degrees)
  • 20
Color
  • Phantom Black
Lubrication system
  • Wet sump
Oil Capacity
  • 5.5 qts / 5.2 l
Maximum Trim Range
  • 22° (-6° to 16°)
Maximum Tilt Range
  • 70° (-6° to 64°)