Taking intelligence to a whole new level.

The iGX270 and iGX390 are technologically advanced, offering you features and performance like no other small engine in the world. With its multi-function, high-performance design combined with the same superior reliability of Honda's legendary GX engines, the iGX sets a new standard for engines.

Common Applications
  • Pressure washers
  • Generators
  • Forestry equipment
  • Construction / industrial equipment
  • Agricultural equipment
  • Water pumps
  • Small Engines


Advanced Technology
  • Integrated ECU (electronic control unit) with a self-tuning regulator (STR) governor system. Learn More
  • Engine senses and adjusts RPMs to match the application's load and speed requirements.
  • ECU enables drive-by-wire remote control operation of the engine and regulates functions such as throttle position.
Fuel Efficient Operation
  • Fuel economy is increased by approximately 15% over a similar conventional engine
  • Auto Throttle
High Power Output
  • Electronic governor minimizes governor droop, increasing available power Learn More
  • Allows the engine to respond significantly faster to the load
Smooth Performance
  • ECU fine tunes the throttle position to maintain a precise engine speed.
  • Precision engineered components result in lower vibration
Exceptionally Quiet
  • Enhanced muffler design reduces overall engine noise
  • Large capacity, multi-chamber exhaust system
  • Reduced mechanical noise due to higher compression and piston design
  • Forged steel crankshaft and rigid crankcase
Proven Reliability
  • Long-life air filter
  • Multi-function Oil Alert Learn More
Easy to Use and Maintain
  • No manual manipulation of the choke or throttle - Easier for inexperienced users to operate
  • Wide fuel filler opening with ratchet-type fuel cap
  • Easy maintenance - ideal for rental applications
  • Easy access connectors for flexible connection of remote control and for ECU programming
  • Externally serviceable Oil Alert
Easy Starting
  • Auto Choke
  • Low effort recoil starter with automatic decompression
  • Camshaft profile is optimized for easy starting
  • Large diameter recoil starter assembly
  • Automotive-style ignition coil on spark plug
  • Digital CDI with higher spark plug voltage Learn More
Emissions Compliant
  • No catalyst necessary
Available Options
  • Spark arrester available
  • Charge and lamp coils with multiple output options available




Engine Type Air-cooled 4-stroke OHV Air-cooled 4-stroke OHV
Bore x Stroke 77 X 58 mm 88 X 64 mm
Displacement 270 cm3 389 cm3
Net Power Output* 8.4 hp (6.3 kW) @ 3,600 rpm 11.7 HP (8.7 kW) @ 3,600 rpm
Net Torque 14.1 lb-ft (19.1 Nm) @ 2,500 rpm 19.5 lb-ft (26.4 Nm) @ 2,500 rpm
PTO Shaft Rotation Counterclockwise (from PTO shaft side) Counterclockwise (from PTO shaft side)
Compression Ratio 8.5:1 8.2:1
Lamp/Charge coil options 3A, 20A 3A, 20A
Carburetor Horizontal type butterfly valve Horizontal type butterfly valve
Ignition System Digital CDI with variable timing Digital CDI with variable ignition timing
Starting System Recoil/electric Recoil/electric
Lubrication System Splash Splash
Governor System Electric STR (Self Tuning) Electric STR (Self Tuning)
Air Cleaner Dual element Dual element
Oil Capacity 1.16 US qt (1.1 L) 1.16 US qt (1.1 L)
Fuel Tank Capacity 5.6 U.S. qts (5.3 liters) 6.4 US qts (6.1 liters)
Fuel Unleaded 86 octane or higher Unleaded 86 octane or higher
Dry Weight 66.7 lb (30.3 kg) 82 lb (37 kg)
WARNING: California Prop 65 Info




Length (min) 16.0" (407mm) 16.0" (407mm)
Width (min) 19.1" (485 mm) 19.1" (485 mm)
Height (min) 17.7" (449 mm) 17.7" (449 mm)




P type Threaded type (SAE) View Details Threaded type (SAE) View Details
E type Tapered shaft View Details Tapered shaft View Details
H type Reduction type PTO View Details Reduction type PTO View Details
Q type Straight shaft View Details Straight shaft View Details
V type Tapered shaft View Details Tapered shaft View Details
L type Reduction type PTO View Details Reduction type PTO View Details
R type Reduction type PTO View Details Reduction type PTO View Details

Performance Curves

iGX270 Performance Curve
iGX390 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.