GX 390 Engine
| 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) |
