Searching for a dependable power source for your commercial equipment, pressure washer, generator, mini bike, or go-kart project? Our selection of used Honda GX390 engines for sale offers the perfect blend of performance, durability, and value. The Honda GX390 has earned a reputation across construction sites, rental fleets, racing tracks, and homeowner garages as one of the most reliable small engines ever built. With its commercial-grade construction, proven longevity (5,000 to 10,000 plus hours in commercial service is routine), and direct compatibility with virtually any 13 HP single-cylinder application, the GX390 is the go-to choice when reliability matters.
The Honda GX390 is a powerhouse in the world of small commercial engines, known for its reliability and versatility across an enormous range of applications. This 389 cc, single-cylinder, air-cooled, OHV (overhead valve) 4-stroke engine delivers 11.7 HP (8.7 kW) at 3,600 RPM with a robust design featuring a durable cast iron cylinder sleeve, ball bearing supported crankshaft, and high compression ratio of 8.2:1 (the live spec listing shows "8:2:1" which is a typo for 8.2:1). Available in both horizontal shaft and vertical shaft configurations with options for recoil start or electric start, the GX390 is purpose-built for serious commercial and industrial use.
You may see the Honda GX390 referenced as either an "11.7 HP" or "13 HP" engine. This is not a different engine , it's the same GX390 with two different power ratings. In 2010, Honda revised its power rating methodology to comply with SAE J1995 gross power testing standards, which produced more conservative numbers. The same GX390 that was rated 13 HP gross before 2010 is now rated 11.7 HP gross. The engine itself, internals, and performance are identical. Older equipment manuals and labels will say "13 HP Honda," while newer documentation says "11.7 HP."
Several engineering features make the GX390 the benchmark for commercial small engines:
The GX390 is suitable for an enormous range of applications. The most common include:
The GX390 competes against several major commercial small engines:
| Engine | Manufacturer | Approx Specs | Notes |
|---|---|---|---|
| Honda GX390 | Honda | 389cc / 11.7 HP / 19.5 lb-ft | Industry benchmark for reliability |
| Briggs Vanguard 13 | Briggs and Stratton | 391cc / 13 HP | Twin-cylinder option also available |
| Kohler CH395 | Kohler | 277cc / 9.5 HP (smaller variant) | Often used in pressure washers |
| Subaru EX40 | Subaru / Robin | 404cc / 12.8 HP | Discontinued in 2017, parts limited |
| Kawasaki FJ400D | Kawasaki | 401cc / 13.5 HP | Premium commercial alternative |
| Predator 13 HP | Harbor Freight (clone) | 420cc / 13 HP | Budget alternative, 80% of Honda performance |
A common question: how does the Honda GX390 compare to the Predator 13 HP from Harbor Freight (or other Chinese clones)?
For commercial / professional use, the Honda's price premium pays for itself in longevity and uptime. For occasional home use or short-life applications (e.g. one season of a yard project), a clone may make economic sense.
The GX390 is designed to be interchangeable across the vast majority of equipment that originally used a GX390 or competitor 13 HP engine. Key compatibility factors:
Call (240) 301-0095 with your equipment make, model, and current engine details for compatibility verification.
A quality used GX390 offers compelling value:
Here at Vaz Auto Solutions, you'll find this used Honda GX390 engine for sale at the most reasonable price possible. Our aim here is to make your hunt for the perfect engine for your pressure washer, generator, mini bike, go-kart, or commercial equipment more seamless and efficient.
| Vehicle | Compatibility |
|---|---|
| Pressure Washers | Most 3,000 to 4,400 PSI commercial pressure washers (DeWalt, Simpson, NorthStar, Mi-T-M, BE, Pressure Pro, etc.) |
| Generators | 5,000 to 7,000 watt portable generators (Honda EM/EB series, Generac, Westinghouse, Briggs, etc.) |
| Concrete Mixers | Towable and stationary concrete mixers (Crown, Multiquip, MBW, IMER, etc.) |
| Plate Compactors and Rammers | Wacker Neuson, Multiquip, BOMAG, Hyundai construction equipment |
| Water Pumps | Honda WT30, NorthStar trash pumps, Multiquip, Briggs and similar 3-inch / 4-inch discharge pumps |
| Mini Bikes | Coleman BT200, BT200X, Massimo MB200, Hammerhead Trailmaster |
| Go-Karts | Honda Stock Class racing karts, kid karts, adult recreational karts |
| Log Splitters | Most commercial / consumer wood splitters using 13 HP class engines |
| Other | Air compressors, hydraulic power packs, wood chippers, stump grinders, tillers, cement saws |
| NOT Compatible | Equipment requiring 2-stroke or diesel power, equipment specifically designed for smaller (GX160/GX200) or larger (GX670/GX690) engines |
| Engine Type | Single-cylinder | 4-stroke | OHV air-cooled gasoline |
|---|---|
| Horsepower | 11.7 HP (8.7 kW) at 3 | 600 RPM (SAE J1995 gross) | formerly rated 13 HP |
| Displacement | 389 cc (23.7 cubic inches) |
| Bore X Stroke | 88 mm x 64 mm |
| Compression Ratio | 8.2:1 |
| Torque | 500 rpm | 19.5 lb-ft (26.4 Nm) at 2 |
| Fuel Type | Unleaded gasoline (87 octane minimum) |
| Fuel Capacity | 6.9 liters (1.8 US gallons) |
| Oil Capacity | 1.1 liters (1.16 US quart) |
| Cooling | Forced air |
| Starting | Recoil (standard) or electric (optional) |
| Ignition | Transistorized magneto |
| Lubrication | Splash with Oil Alert low-oil shutdown |
| Pto Shaft | Tapered / threaded / splined depending on application |
| Cylinder Sleeve | Cast iron |
| Crankshaft Bearings | Ball bearings |
| Configuration | Horizontal shaft (most common) or vertical shaft |
| Dry Weight | ~31 kg (68 lbs) |
| Manufacturer | Honda Motor Co. | Ltd. (Honda Power Products division) |
Contact (240) 301-0095 within 15 days.
