9.9 HP CT Fourstroke

Equipped with a larger gear case for more thrust, the Mercury 9.9hp Command Thrust FourStroke delivers big-time power and control that wider, heavier boats demand. The Command Thrust gear case allows a wider selection of propellers to get the performance just right. So, if you're powering a barge, pontoon or heavier displacement hull, the 9.9hp is the perfect partner. Exclusive to Mercury and designed for easy control, the Multi-function tiller handle makes boating easy allowing gear shift, throttle, steer, tilt and stop the engine with just one hand. All recreational Mercury outboard models from the 2.5 - 350hp range now come with 3+3= 6 years of warranty coverage. World class engines, world class support, that's what you get when you buy a Mercury.

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
Starting Electric
Steering Remote
Shaft length 15" / 381 mm
20" / 508 mm
25" / 635 mm
Gearcase ratio 2.08:1
Dry weight *Lightest model available 84 lbs / 38 kg
CARB star rating 3
Emissions Star Rating 3
Bore and stroke 2.16 x 1.73" / 55 x 44 mm
Ignition CDI w/electronic spark advance
Fuel system Carbureted
Cooling system Water-cooled with thermostat
Gear shift F-N-R
Gearcase options Standard
Trim positions Ratcheting
Exhaust system Through prop
Shallow water drive Yes
Shallow water trim range (degrees) 16
Integrated fuel tank (gal / L) 3.2 / 12
Remote fuel tank standard (gal / L) 3.2 / 12
Color Phantom Black


Horse Power (hp)
  • 9.9

Engine 1

Engine Make Mercury
Horse Power 9.9