Mercury 40 HP LW Twostroke – The secret to our mid-range is our renowned reliability thanks to its cool running. With high volume, low pressure, floppy-vane water impellers keeping operating conditions down.

Calculate your fuel savings

The Mercury Fuel Savings Calculator will allow you to easily calculate the possible fuel savings of a Mercury FourStroke outboard!

Choose how you use your boat, select the TwoStroke and FourStroke horsepower – and our tool will show your potential fuel savings. If you're looking to upgrade or add more power, you can even choose different FourStroke and TwoStroke horsepower options!

Largest displacement.

With the largest engine capacity displacement in their horsepower category, the TwoStrokes give you more low-end thrust.

HP / kW
  • 40 / 29.8
Displacement (CID/CC)
  • 42.5 / 697
Cylinder Configuration
  • I-3
Full throttle RPM
  • 5000 – 5700
Fuel induction system
  • Loop-charged (3 carb)
Starting
  • Manual
Steering
  • Tiller
Shaft length
  • 20″ / 508 mm
Gearcase ratio
  • 1.85 : 1
Dry weight *Lightest model available
  • 72
Emissions Star Rating
  • 1
Bore and stroke
  • 68 x 64
Trim system
  • 4 position
  • Manual
Oil Injection
  • Pre-mix
  • Standard