At 21.4 cubic inches, this engine delivers the
strong low-end torque needed to get the hull up
on plane, with quicker throttle response and acceleration.
Mariner Fourstrokes are designed with a boat load
of user-friendly features, such as our multifunction tiller handle.
This tiller handle gives you easy one-handed
operation of shifting, stopping, throttle, throttle friction, and tilt.
More control equals better maneuverability.
Mariner’s “wishbone” style motor mount system cradles
the powerhead and absorbs the torsional rotation
of the crankshaft. By isolating and reducing the vibration
transmission to your boat, it provides a smooth driving experience.
Mariner’s 20hp FourStrokes have dual water pickups.
So even if you end up in the shallows, your engine
will keep its cool and not overheat
HP/Kw @ Prop
20 / 14.7
Full throttle RPM
Displacement (CID / CC)
21.4 / 351
2.40 x 2.36in
Bore and Stroke (in / mm)
61 x 60mm
Fuel Induction System
2 valves per cylinder, single overhead cam (SOHC)
CDI w/electronic spark advance
12 amp / 138 watt
Water-cooled with thermostat
Shallow water drive
Shallow water trim range (degrees)
Mercury 4-Stroke Outboard Oil
87 octane/up to 10% ethanol
Remote fuel tank standard (gal / L)
6.6 / 25
Low oil pressure
Engine Protection Operator Warning System
15 in (381mm)
20 in (508 mm)
Dry Weight * Lightest model available
115lbs / 52kg
CARB Star Rating