Quality and performance come standard.
Honda’s GX series engines are legendary for superior reliability and performance. And there’s no doubt about it: the GX120 lives up to the legend. Lower noise levels, lower vibration, and lower emissions – without sacrificing power output or performance.


Commercial lawn and garden equipment
Tillers / cultivators
Construction / industrial equipment
Agricultural equipment
Water pumps




Engine Type Air-cooled 4-stroke OHV Air-cooled 4-stroke OHV Air-cooled 4-stroke OHV
Bore x Stroke 60 X 42 mm 68 X 45 mm 68 X 54 mm
Displacement 118 cm3 163 cm3 196 cm3
Net Power Output* 3.5 HP (2.6 kW) @ 3,600 rpm 4.8 HP (3.6 kW) @ 3,600 rpm 5.5 HP (4.1 kW) @ 3,600 rpm
Net Torque 5.4 lb-ft (7.3 Nm) @ 2,500 rpm 7.6 lb-ft (10.3 Nm) @ 2,500 rpm 9.1 lb-ft (12.4 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side) Counterclockwise (from PTO shaft side) Counterclockwise (from PTO shaft side)
Compression Ratio 8.5:1 9.0 : 1 8.5:1
Lamp/Charge coil options 25W, 50W 25W, 50W / 1A, 3A, 7A 25W, 50W / 1A, 3A, 7A
Carburetor Butterfly Butterfly Butterfly
Ignition System Transistorized magneto Transistorized magneto Transistorized magneto
Starting System Recoil Recoil Starter Recoil Starter
Lubrication System Splash Splash Splash
Governor System Mechanical Centrifugal Mechanical Mechanical
Air Cleaner Dual Element Dual Element Dual element
Oil Capacity 0.59 US qt. (0.56 L) 0.61 US qt. (0.58 L) 0.63 US qt (0.6l)
Fuel Tank Capacity 2.1 U.S. qts (2.0 liters) 3.3 U.S. qts (3.1 liters) 3.3 U.S. qts (3.1 liters)
Fuel Unleaded 86 octane or higher Unleaded 86 octane or higher Unleaded 86 octane or higher
Dry Weight 29 lbs. (13.0 kg) 33 lbs. (15.1 kg) 35 lbs. (16.1 kg)
Fuel Efficient, High Output Operation
  • Precision camshaft design offers precise valve timing and optimal valve overlap for better fuel efficency
  • OHV design for increased efficiency and optimal power transfer
  • High compression ratio for better fuel efficiency
Smooth Performance
  • Precision engineered components result in lower vibration
  • Ball bearing supported crankshaft for greater stability
Exceptionally Quiet
  • Even quieter than previous model!
  • Large capacity, multi-chamber exhaust system
  • Reduced mechanical noise due to light weight, noise-reducing materials
  • Forged steel crankshaft and rigid crankcase
  • Helical cut gears
  • Sophisticated air intake system
Proven Reliability
  • Oil Alert Learn More
  • New carburetor chamber coating and carburetor filter help to protect against fuel impurities
  • Cast iron cylinder sleeve
  • High quality materials, fit, and finish
  • Dual element air cleaner
  • Fuel Valve
  • 3-Year Limited Warranty
Easy to Use and Maintain
  • Simple throttle control
  • Large fuel tanks
  • Large automotive type fuel cap
  • Dual oil drains and fill
  • Easy, convenient, heavy duty control box
  • Easily accessible spark plug
Easy Starting
  • Heavy duty recoil starter
  • Ergonomic, easy to grip recoil rope design
  • Automatic mechanical de-compression system Learn More
Emissions Compliant
  • Lower emissions, same power output!
  • CARB and EPA certified
  • No catalyst necessary
Available Options
  • Gear reduction options
  • Spark arrester available