Loading... Please wait...
The GX390 is all new for 2010, featuring more power, quieter performance, lower fuel consumption, and lower emissions. With new features and better performance, the new GX engines establish themselves yet again as the best engines in the business.
Common Applications
Fuel Efficient, High Output Operation
Smooth Performance

Exceptionally Quiet
Proven Reliability
Easy to Use and Maintain
Easy Starting
Emissions Compliant
Available Options
Specifications
| Engine Type | Air-cooled 4-stroke OHV |
| Bore x Stroke | 88 X 64 mm |
| Displacement | 389 cm3 |
| Net Power Output* | 11.7 HP (8.7 kW) @ 3,600 rpm |
| Net Torque | 19.5 lb-ft (26.4 Nm) @ 2,500 rpm |
| PTO Shaft Rotation | Counterclockwise (from PTO shaft side) |
| Compression Ratio | 8.2:1 |
| Lamp/Charge coil options | 25W, 50W / 1A, 3A, 10A, 18A |
| Carburetor | Butterfly Float Type |
| Ignition System | Digital CDI with variable timing |
| Starting System | Recoil/electric |
| Lubrication System | Splash |
| Governor System | Centrifugal Mass Type |
| Air cleaner | Dual element |
| Oil Capacity | 1.16 US qt (1.1 L) |
| Fuel Tank Capacity | 6.4 U.S. qts (6.1 liters) |
| Fuel | Unleaded 86 octane or higher |
| Dry Weight | 69 lb (31.5 kg) |
| Dimensions | |
| Length (min) | 16.0" (407 mm) |
| Width (min) | 19.1" (485 mm) |
| Height (min) | 17.7" (449 mm) |
| PTO Shaft Options | |
| E type | Tapered shaft |
| H type | Reduction type PTO |
| L type | Reduction type PTO |
| P type | Threaded type (SAE) |
| Q type | Straight shaft |
| R type | Reduction type PTO |
| V type | Tapered shaft |
*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.