Honda gx 390 engine DIY repair

In detail: the honda gx 390 engine do-it-yourself repair from a real master for the site my.housecope.com.

Manual for minor repairs of engines Honda (Honda) GX120, GX160, GX200, GX240, GX270, GX340, GX390, GX610-690.

If you have the simplest car repair skills, then you can deal with some of the malfunctions in Honda engines yourself. However, if you doubt your skills or simply do not want to bother with your Honda engine repair yourself, we are always ready to help you. We are always ready to make high-quality repair of the Honda engine, using original or tested non-original spare parts.

Always read the owner's manual before operating your Honda engine for the first time.

Always close the fuel cock after work and when transporting.
Never overturn or tilt a Honda engine towards the carburetor and cylinder side.
Do not forget to change the oil in your Honda engine, the frequency of replacement is 100 hours.

Frequent questions related to minor breakdowns of Honda engines, which, if desired, can be eliminated with your own hands.

1. The engine will not start:
Almost all Honda engines have oil level protection in the crankcase. If the oil level is insufficient, the ignition system is blocked and there is no spark. Always check the oil level before starting work.
The next reason for the absence of a "spark" may be a malfunction of the spark plugs, so it is advisable to have them in stock.
If all of the above does not help, there is a "spark" but the spark plug is dry, we climb into the carburetor. During long-term storage of equipment, gasoline decomposes and deposits in the form of plasticine or glue are formed in the carburetor, which clog the main fuel jet. It is necessary to remove the carburetor, disassemble, and rinse all parts well. Particular attention should be paid to the fuel jet.

Video (click to play).

2. Honda engine emits black smoke and develops insufficient power.
The reason is that the air filter is heavily clogged. Depending on the type of air filter, the paper filter must be replaced with a new one, and the sponge filter can be washed and reused.

3. Gasoline in oil:
The engine starts, runs for a few minutes, then heavy smoke appears from the muffler and the engine stops.
Gasoline enters the oil when the carburetor shut-off needle does not hold the gasoline pressure.
It is possible that dirt has got under the needle in the carburetor and the valve does not hold. During transportation, the fuel cock did not close and the breathing valve in the gas tank cap did not work.

We are always ready to make high-quality repair of the Honda engine, using original or tested non-original spare parts.

The Honda GX 390 engine is the most popular engine for power plants, road construction equipment, for small mechanization machines, generators, water pumps and other industrial equipment. etc. Unrivaled power, economy and durability as well as high reliability with a long service life. Meeting the most stringent environmental requirements today and in the future. Honda GX390 4-stroke gasoline engine with overhead valve (OHV), horizontal shaft, air-cooled, cylinder angled 25 °

TROUBLESHOOTING ENGINE

Difficult to start, there is fuel, but no spark in the spark plug

Check clearance, insulation or replace spark plug.

Clean or replace spark plug.

Short circuit due to poor plug insulation?

Check plug insulation, replace if worn.

Adjust the correct clearance.

Difficult to start, there is fuel and there is a spark in the spark plug

Is the ON / OFF switch defective?

Check switch wires, replace switch.

Faulty starter coil?

Replace the starter coil.

Wrong spark plug gap, contamination?

Adjust the correct gap, clean the contacts.

Is the capacitor insulation worn out or short-circuited?

Is the spark plug wire faulty or short-circuited?

Replace defective spark plug wires.

Difficult to start, there is fuel, there is a spark in the spark plug, compression is normal

Purge the fuel system and fill with the correct fuel.

Is there water or dirt in the fuel system?

Purge the fuel system.

Air filter dirty?

Clean or replace the air filter.

Difficulty starting, fuel present, spark plug present, low compression

Clogged or defective suction / discharge valve?

Worn out piston ring and / or cylinder?

Replace piston rings and / or piston.

Cylinder head and / or spark plug improperly tightened?

Tighten the cylinder head bolts and spark plug correctly.

Is the head gasket and / or spark plug gasket damaged?

Replace the cylinder head seals and spark plugs.

There is no fuel in the carburetor

Fill with the correct type of fuel.

Fuel cock not open correctly?

Apply grease to loosen the fuel cock, replace if necessary.

Replace the fuel filter.

Is the fuel tank hole clogged?

Clean or replace the tank cap.

Power attenuation, compression is correct and action is correct

Air filter dirty?

Clean or replace the air filter.

Incorrect carburetor level?

Check the setting, re-run the carburetor.

Spark plug defective?

Clean or replace spark plug.

Attenuation of power, compression is correct, but the action is not correct

Purge the fuel system and fill with the correct type of fuel.

Clean or replace spark plug.

Is the starter coil defective?

Replace the starter coil.

Incorrect spark plug heat value?

For over 40 years, Honda has been supplying versatile combustion engines to OEMs around the world.

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GX - series professional general-purpose gasoline engines are specially designed for long and trouble-free operation in extreme conditions. GXV - (Vertical shaft motors are used for lawn mowers, worm gear cultivators, etc.)

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

The GX 390 is an OHV gasoline engine with an air-cooled 25 degree cylinder and a horizontal crankshaft. Displacement 389 cm 3, maximum power output 13 hp. (sometimes the operating instructions indicate the rated and net power, which is closer to real conditions). The maximum power is used more for advertising purposes.

The graph of the dependence of power and torque value depending on the engine speed.

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

Modifications of the GX 390 motors

There are many different modifications for this engine from Honda to meet the needs of any user. Varieties take into account the following parameters:

2.the presence of the gearbox and its type

4.type of starter (manual, electric)

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

Decoding of Honda engine modifications using the GX 160 as an example


Engine oil for Honda GX 390 engine

It is recommended to operate the engine with an SAE 10W-30 engine oil that is suitable for all ambient temperatures.Engine oils with different viscosities shown in the table may be used provided that the average air temperature in your area does not exceed the specified temperature range.

Use Honda Four-Stroke Oil or an equivalent high detergent, premium engine oil that is certified to US auto manufacturers' requirements for SG, SF / CC, CD oils per accepted engine oil classification, or better. The belonging of engine oils to classes SG, SF / CC, CD will be indicated by these letter designations on the container.

Do not overfill the engine with engine oil. Check the oil level with the engine horizontal.

GX Series Engine Gearbox Oil

Fill the gearbox with the same engine oil as recommended for the engine itself. Fill in oil up to the upper maximum Image - Engine honda gx 390 DIY repair
marks on the dipstick (gearbox with gear ratio 1/2 and centrifugal clutch). Reducer with gear ratio 1/2
(without centrifugal clutch) and the gearbox with a gear ratio of 1/6 are lubricated with engine oil in the engine crankcase.

Spark plug - recommended types BPR6ES (NGK) W20EPR-U (DENSO) Inspect the spark plug, replace it if the electrodes are worn out or there are cracks on the insulator. The gap should be 0.70 -0.80 mm. Bend the side electrode if necessary.

Adjusting the carburetor of the GX engines

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

2) With the engine running at idle speed, turn the idle speed adjustment screw in the desired direction so that the engine runs at its highest speed.

Sometimes, if the carburetor is completely misaligned, you need to restore the original settings and then adjust the motor more accurately. Correct adjustment is usually achieved by unscrewing the idle speed adjustment screw the next RPM from the stop position (light touch).

The number of revolutions of the idle speed adjustment screw:

Float chamber with balancing hole, vented 2-1 / 4 turn

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

3) After the idle adjustment screw is correctly installed, turn the throttle stop screw to obtain the rated idle speed.

Honda GX Engine Maintenance Intervals

Air filter maintenance

Double filter element, filter of silent, cyclonic type:

1) Unscrew the nut, remove the air filter cover and unscrew the wing nut. Remove the filter elements and separate them. Inspect both elements carefully and replace if holes or breaks are found.

2) Paper filter element. Hit the hard part of the filter element lightly several times to remove excessive accumulated dirt, or blow through the filter element with low pressure compressed air (no more than 30 psi, 2.1 kgf / cm2) from the inside out. Do not try to clean the filter element with a brush. The brush will only rub dirt into the filter paper. Image - Engine honda gx 390 DIY repair

3) Foam 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 the engine will smoke a lot during the first start.

4) Direct light through the filter elements and carefully check their condition for transmission. Reinstall the filter elements if they have no through holes or tears. If the air filter continues to degrade engine performance, replace it with a new one.

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Single element filter

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

2) Clean, rinse and lubricate the foam element with oil.

Oil bath filter

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

2) Clean, rinse and lubricate the foam element with oil.

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

4) Fill the air filter housing up to the marked level with the recommended engine oil for the engine (see recommended engine oil details).

The official site of Honda in Russia from this site you can go to dealers in Russia:

The official website of the manufacturer of general-purpose engines of Honda in Russia honda-engines-eu.com/ru - the site provides mainly technical support and contains a lot of technical information.

Official distributor of Honda engines in Russia - assistance in finding dealers for service and repair.

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

Gearbox options for the GX 390 engine

Honda-GX240-GX390 engine - user manual download

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

The Honda GX160 engine Assembly new piston group

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