Login or create an account
CloseReturning Customer
I am a returning customer
Login or create an account
CloseRegister Account
If you already have an account with us, please login at the login form.
Your Account Has Been Created!
Thank you for registering with Juna Tools!
You will be notified by e-mail once your account has been activated by the store owner.
If you have ANY questions about the operation of this online shop, please contact the store owner.
Account Logout
You have been logged off your account. It is now safe to leave the computer.
Your shopping cart has been saved, the items inside it will be restored whenever you log back into your account.
Honda GX390 389cc OHV Air Cooled Engine
- $410.00
- Brands Honda
- Product Code: GX390UT2QNR2
- Availability: In Stock
Honda GX390 389cc OHV Air-Cooled 4-Stroke Horizontal-Shaft Engine Product Overview The Honda GX390 389cc OHV Air-Cooled 4-Stroke Engine is a heavy-duty general-purpose gasoline engine designed for demanding commercial, agricultural, construction, landscaping, and industrial equipment. As part of Honda's proven GX Series, the GX390 combines a large-displacement single-cylinder design with overhea..
Features of Honda GX390 Horizontal 4 Stroke Engine
Honda GX390 389cc OHV Air-Cooled 4-Stroke Horizontal-Shaft Engine
Product Overview
The Honda GX390 389cc OHV Air-Cooled 4-Stroke Engine is a heavy-duty general-purpose gasoline engine designed for demanding commercial, agricultural, construction, landscaping, and industrial equipment. As part of Honda's proven GX Series, the GX390 combines a large-displacement single-cylinder design with overhead-valve technology for dependable power, durability, and efficient operation.
Its horizontal-shaft configuration makes it suitable for equipment such as water pumps, pressure washers, generators, tillers, compactors, and other machinery engineered for a horizontal PTO engine.
Key Features
- 389cc displacement provides strong power for demanding applications.
- Single-cylinder OHV design delivers efficient and dependable engine performance.
- 4-stroke gasoline engine eliminates the need to mix gasoline and engine oil.
- Air-cooled system helps regulate operating temperature.
- Horizontal PTO shaft suits a wide variety of utility equipment.
- Honda GX Series construction is designed for commercial and professional use.
- Large displacement provides strong torque for equipment operating under load.
- Designed for straightforward routine maintenance and long service life.
- Available in multiple configurations, including recoil- and electric-start versions depending on model.
Product Specifications
| Specification | Details |
|---|---|
| Brand | Honda |
| Engine Series | GX Series |
| Engine Model | GX390 |
| Product Type | Horizontal-Shaft Gasoline Engine |
| Displacement | 389cc |
| Cylinder Configuration | Single Cylinder |
| Engine Cycle | 4-Stroke |
| Valve Configuration | OHV |
| Cooling System | Air-Cooled |
| Fuel Type | Unleaded Gasoline |
| Bore × Stroke | 88 × 64 mm |
| Starting System | Model-dependent |
| Shaft Orientation | Horizontal |
| Maximum Power | Approximately 11.7 hp at 3,600 rpm* |
| Rated Power | Approximately 10.2 hp at 3,600 rpm* |
| Application | Commercial, agricultural, construction, industrial, and utility equipment |
*Power ratings can vary by specification standard and market. Verify the exact GX390 model and specification sheet for the applicable rating.
Powerful 389cc Engine
The 389cc GX390 is designed for applications that require substantial torque and reliable power. Its single-cylinder architecture keeps the engine mechanically straightforward, while the large displacement provides the capacity needed for equipment that operates under significant loads.
The engine is commonly selected for applications where a compact utility engine needs to deliver more power than smaller GX Series models such as the GX160 or GX200.
OHV 4-Stroke Design
The overhead-valve (OHV) configuration is designed to provide efficient combustion and dependable operation. As a 4-stroke engine, the GX390 uses a separate lubrication system rather than requiring gasoline and oil to be premixed.
This design makes the engine practical for equipment that is used regularly and requires predictable, serviceable power.
Air-Cooled Operation
The GX390 uses an air-cooling system to manage engine operating temperature. Air cooling eliminates the need for a liquid radiator and associated coolant system, helping keep the engine's design relatively simple.
Keeping the cooling fins and surrounding areas free of dirt and debris is important for maintaining proper airflow during operation.
Horizontal-Shaft Configuration
The horizontal PTO shaft allows the GX390 to be integrated into machinery designed around a horizontal engine layout.
Common applications include:
- Water pumps
- Pressure washers
- Generators
- Tillers
- Plate compactors
- Construction equipment
- Agricultural machinery
- Landscaping equipment
- Utility equipment
- Industrial machinery
When replacing an existing engine, it is important to match the shaft diameter, shaft length, keyway, shaft rotation, mounting pattern, and shaft-centerline height rather than relying only on engine displacement.
Commercial-Grade GX Series Construction
Honda's GX Series is designed for general-purpose equipment applications where durability and dependable operation are important. The GX390's robust construction makes it appropriate for professional and commercial equipment that may operate for extended periods.
Routine maintenance should include regular engine-oil checks and changes, air-filter service, spark-plug inspection, cooling-system cleaning, and fuel-system maintenance according to Honda's recommended schedule.
Starting Options
The GX390 platform is available in different configurations. Depending on the exact model, it may be equipped with:
- Recoil starting
- Electric starting
- Electric start with charging capability
If this engine is being purchased as a replacement, confirm the complete model suffix to ensure the starting and electrical configuration matches the intended equipment.
Why Choose the Honda GX390?
The Honda GX390 is a strong choice when an application requires a durable, relatively compact gasoline engine with substantial displacement. Its combination of 389cc capacity, OHV technology, air cooling, 4-stroke operation, and horizontal PTO output makes it adaptable to a wide variety of equipment.
It is particularly appropriate for users who need reliable power for demanding pumps, generators, construction machines, agricultural equipment, and other utility applications.
Installation & Compatibility
Before ordering, compare the engine with the equipment's original specifications. Important compatibility factors include:
- Engine model and suffix
- Shaft diameter and length
- Keyway dimensions
- Shaft rotation
- Mounting-hole pattern
- Shaft height
- Governor and throttle controls
- Fuel-system configuration
- Exhaust arrangement
- Electrical/charging system
- Starting system
- Overall engine dimensions
Important Product Note
GX390 specifications vary by model configuration and market. The commonly quoted 389cc displacement identifies the GX390 family, but exact horsepower, shaft dimensions, starting system, fuel-tank configuration, and electrical equipment can differ between versions.
For an accurate product listing, verify the full Honda GX390 model number and suffix before publishing exact technical specifications or using the engine as a replacement.