Honda Gx 390 Engine – Specifications, Operating Instructions

Honda GX 390 engine. Technical specifications, manual

For over 40 years, Honda has been supplying universal combustion engines to end-equipment manufacturers around the world.

Gx. series professional gasoline engines for general use are designed specifically for long and uninterrupted operation in especially difficult conditions. Gxv. (engines with a vertical shaft are used for lawn mowers, motor cultivators with a worm gear, etc.)

The Honda GX 390 gasoline engine is suitable for a wide range of applications in harsh conditions, for example, in construction equipment, cultivators, gas generators, power plants, welding machines, pumps and other industrial equipment.

The GX 390 is a gasoline OHV engine with an air-cooled system, a cylinder at an angle of 25 degrees, and a horizontal crankshaft. The volume of the cylinder is 389 cm 3, the maximum output power is 13 hp. (sometimes in the operating instructions indicate the rated and useful power, which is closer to real conditions). Maximum power is more used for advertising purposes.

Graph of power and torque depending on the engine speed.

Honda Gx 390 Engine. Specifications, Operating Instructions

As you can see the nominal operating speed at which the engine provides the greatest torque of about 2500 rpm. Some experts consider the value of torque to be a more significant indicator than power. over, everything is more and more unequivocal here without tricks and tricks.

Honda GX 390 Engine Specifications

Engine modifications GX 390

For this Honda engine, there are many different modifications to meet the needs of any user. Varieties take into account the following parameters:

2. the presence of the gearbox and its type

3. oil sensor availability

4. starter type (manual, electric)

5. other differences (fuel filter, air filter, muffler, charging coil, control unit, etc.)

Explanation of Honda engine modifications on the example of the GX 160

Engine oil for the Honda GX 390 engine

It is recommended to operate the engine with engine oil with a viscosity of SAE 10W-30, which is suitable for any ambient temperature. Motor oils with a different viscosity indicated in the table can be used provided that the average air temperature in your area does not exceed the specified temperature range.

Use Honda engine oil for four-stroke engines or equivalent high-performance engine oil, first-class engine oil certified in accordance with the requirements of US automobile standards for SG, SF / CC, CD oils according to the accepted classification of motor oils, or exceeding them. The belonging of motor oils to the classes SG, SF / CC, CD will be indicated by these lettering on the container.

Do not overfill the engine with engine oil. Check the oil level on a horizontally mounted engine.

GX Series Engine Gearbox Oil

Fill the gearbox with the same engine oil that is recommended for the engine itself. Fill oil to the upper maximum level.
marks on the dipstick (gearbox with gear 1/2 and centrifugal clutch). 1/2 gear reducer
(without centrifugal clutch) and a gearbox with a gear ratio of 1/6 are lubricated with engine oil in the crankcase.

Spark plug. recommended types BPR6ES (NGK) W20EPR-U (DENSO) Inspect the spark plug, replace it if the electrodes are worn or there are cracks in the insulator. The clearance should be mm. If necessary, bend the side electrode.

GX carburetor adjustment

1) Start the engine and let it warm up to normal operating temperature.

2) With the engine idling, rotate the idle adjustment screw in the desired direction so that the engine starts to operate at the highest speed.

Sometimes if the carburetor is completely misregistered, you need to restore the original settings and then adjust the motor more precisely. Correct adjustment is usually achieved after loosening the idle adjustment screw the next number of revolutions from the stop position (light touch).

Video: Honda Gx 390 Engine. Specifications, Operating Instructions

Number of revolutions of the idle adjustment screw:

Float chamber with balancing hole communicating with the atmosphere 2-1 / 4 turns

Float chamber with balancing hole communicated with diffuser 2-1 / 4 turns

3) After correctly installing the idle adjustment screw, turn the throttle retaining screw to obtain the rated idle speed.

Frequency of maintenance of Honda GX engines

Air Filter Maintenance

Double filter element, silent filter, cyclone type:

1) Loosen the nut, remove the air filter cover and unscrew the wing nut. Remove the filter elements and separate them. Carefully inspect both elements and replace if holes or tears are found.

2) Paper filter element. Strike the solid part of the filter element slightly several times to remove excessively accumulated dirt or blow through the filter element with low-pressure compressed air (pressure not exceeding 30 psi, 2.1 kgf / cm2) from the inside out. Do not attempt to brush the filter element. The brush will only rub dirt into the filter paper

3) Porous plastic filter element. Wash in warm soapy water, rinse and dry thoroughly. Soak the filter element in clean engine oil. Squeeze out all the excess. If there is an excess of oil in the porous filter element, then during the first start-up the engine will smoke very much.

4) Direct the light through the filter elements and carefully check their condition for clearance. Replace the filter elements if they do not have through holes or tears. If the air filter continues to reduce engine performance, replace it with a new one.

Single element filter

1) Unscrew the wing nut, remove the air filter cover and the foam plastic element. Carefully inspect the filter element and if any through holes or tears are found, replace.

2) Clean, rinse and oil the foam plastic filter element.

Oil bath filter

1) Unscrew the wing nut, remove the air filter cover and the foam plastic element. Carefully inspect the filter element and if any through holes or tears are found, replace.

2) Clean, rinse and oil the foam plastic filter element.

3) Drain the oil from the air filter housing and wash off any accumulated dirt with a non-flammable solvent. Dry the air filter housing.

4) Fill the air filter housing to the marking level with engine oil recommended for the engine (see information on recommended engine oil).

Honda official website from this site you can go to dealers:

The official website of the manufacturer of general-purpose engine companies Honda The site provides mainly technical support and contains a lot of technical information.

The official distributor of Honda engines is assistance in finding dealers for service and repair.

Overall dimensions of the Honda GX 390 engine depending on a power take-off shaft

Gearbox Options for GX 390 Engine

Honda GX 390 Engine User Manuals

Engine Honda-GX240-GX390. instruction manual download

Complete user manual for the Honda GX 390 (133 pages). This manual presents: overall and installation dimensions, assembly diagram, maintenance intervals, carburetor GX 390 adjustment, assembly and disassembly, information on installing the electric starter, valve adjustment, repair instructions, gear types and much more.