Quality and performance come standard.

GXR120 is uniquely developed as an ideal source of power for rammers – equipment used to compact soil or other granular material. With superb durability and reliability for these heavy-duty applications, the GXR120 is more than ready to meet the high demands required.

Common Applications
  • Commercial Rammers


Developed Specifically for Rammer Applications
  • Designed to power 110-lb. to 175-lb. rammers at multiple altitudes with ease.
  • More power than the GX100, with a compact, lightweight engine footprint for additional versatility in frame mounting
Fuel Efficient, High Output Operation
  • OHC design developed specifically for increased efficiency
  • Optimal power transfer for better fuel efficiency
Smooth Performance
  • Precision engineered components result in lower vibration
  • Ball bearing supported crankshaft for greater stability
Exceptionally Quiet
  • New design reduces operation noise by 1dB over the original GX100
  • Compact exhaust system is 22mm narrower than the GX100, yet quieter
  • Maintenance-free, low-noise timing belt creates a smaller, lighter and quieter engine
  • Reduced mechanical noise due to light weight, noise-reducing materials
  • Forged steel crankshaft and rigid crankcase
Proven Reliability
  • A special cast-iron cylinder sleeve and a high carbon-steel, dual-ball bearing crankshaft provide improved engine strength for rammer applications.
  • The recoil starter and fan cover are even more robust through the incorporation of steel in the design.
  • Innovative lubrication system with a dual-breather chamber optimizes engine lubricating performance in most rammer operating conditions
  • Oil Alert Learn More
  • New carburetor chamber coating and carburetor filter help to protect against fuel impurities
  • High quality materials, fit, and finish
  • 3-Year Limited Warranty
Easy to Use and Maintain
  • Simple throttle control
  • 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
  • No catalyst necessary



Engine Type Air-cooled 4-stroke OHC
Bore x Stroke 60 X 43 mm
Displacement 121 cm3
Net Power Output* 3.1 hp (2.3 kW) @ 3,600 rpm
Net Torque 4.6 lb-ft (6.3 Nm) @ 3,000 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side)
Compression Ratio 8.6:1
Lamp/Charge coil options Oil alert (LED not included)
Carburetor Multiple options available
Ignition System Transistorized magneto
Starting System Recoil
Lubrication System Forced spray system
Governor System Mechanical
Air Cleaner Multiple options available
Oil Capacity 0.29 US qt. (0.28 L)
Fuel Tank Capacity NA
Fuel Unleaded 86 octane or higher
Dry Weight 22.9 lbs. (10.4 kg)
WARNING: California Prop 65 Info



Length (min) 10.2” (259 mm)
Width (min) 11.5” (294 mm)
Height (min) 11.4” (290 mm)



K type (tapered) Rammer View Details
K type (straight) Straight shaft View Details

Performance Curves

GXR120 Performance Curve

The SAE J1349 standard measures net horsepower with the manufacturer’s production muffler and air cleaner in place.Net horsepower more closely correlates with the power the operator will experience when using a Honda engine powered product.The power rating of the engines indicated in this document measures the net power output at 3600 rpm(7000 rpm for model GXH50, GXV50, GX25 and GX35) and net torque at 2500 rpm, as tested on a production engine. Mass production engines may vary from this value.Actual power output for the engine installed in the final machine will vary depending on numerous factors, including the operation speed of the engine in application, environmental conditions, maintenance and other variables.