DIY electric generator repair

In detail: do-it-yourself electric generator repair from a real master for the site my.housecope.com.

Hello dear motorists! Today I will tell you how to repair a generator with your own hands. You may have already encountered such a problem, when the battery discharge indicator suddenly came on on the dashboard, this means that your car has lost its charging, and you will not go long, the battery will last for a maximum of 1-2 hours.

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Do not rush to throw away the generator. Try to repair it first. The most common generator malfunction is brush wear.

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To check the brush assembly, you need to remove the rear plastic cover by bending the three plastic clips located in a circle.

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Remove the cover, unscrew the two screws and remove the voltage regulator.

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Check the wear of the brushes, if the residual length of the brushes is less than five millimeters, feel free to buy a new voltage regulator in the store. Sometimes it happens that the generator does not charge or recharges the battery, this is also a malfunction of the voltage regulator. The normal voltage of the generator is 13.5 to 14.5 volts, depending on the engine speed and the load on the generator.

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The next generator malfunction is a breakdown of the diode bridge. To check the diodes, the diode bridge must be removed. We unscrew the bolts that hold the diode bridge.

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Bend the wires to the side.

Image - DIY electric generator repair

Image - DIY electric generator repair

Remove the diode bridge. How to check a diode bridge. Read here: How to check a diode bridge?

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After removing the diode bridge, be sure to check the stator windings. We do this, turn on the multimeter in dial mode and check all three stator windings for an open. All windings must ring among themselves.

Video (click to play).

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Next, we check the short to ground. We connect one probe of the multimeter to ground, and the second is alternately connected to the terminals of the windings. There should be no short circuit to ground.

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Similarly, we check the armature winding.

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We check the anchor, there is no short circuit to ground.

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Now I will show you how to disassemble the alternator to replace the bearings. We unscrew the four screws connecting the two halves of the generator together.

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Unscrew the nut and remove the pulley.

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Using a screwdriver, carefully split the generator in two so as not to damage the aluminum covers.

Image - DIY electric generator repair

Image - DIY electric generator repair

Image - DIY electric generator repair

Replace defective bearings with new ones. Reassemble the generator in reverse order.

Friends, I wish you good luck! See you in new articles!

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Gasoline generators, even if they are made in China, very reliable with proper care... Nevertheless, during their operation, small problems can arise that can usually be quickly fixed with your own hands. Serious breakdowns with the knowledge of the owner of the device and the principle of operation of the generator will also not be able to disable it for a long time.

If you arrange possible malfunctions of the gas generator in a kind of rating, you get the following list:

  • Failure or contamination of the spark plug: difficult or impossible starting, unstable operation.
  • Clogged carburetor: difficult starting, excessive fuel consumption, unstable operation under constant load.
  • Failure of the ignition coil: no spark, inability to start.
  • Starter breakdowns: breakage, biting of the cable, destruction of the ratchet.
  • Violation of valve clearances: difficult starting, increased noise during operation.
  • Wear of brushes (on synchronous generators) - lack of output voltage.
  • Speed ​​governor malfunction: floating engine speed, dips when changing the load.
  • Wear of the bearings of the crankshaft and the rotor of the generator - an increase in operating noise, oil leakage.
  • Wear of the cylinder, piston rings - difficult starting of a cold engine, excessive oil consumption.

It does not take into account breakdowns that result from a gross violation of the rules for operating the generator: for example, seizures on the crankshaft neck due to insufficient oil level, burnout of the generator windings or voltage converter (on inverter gas generators) with frequent overloads.

In fact, malfunctions of a gasoline generator can be divided into three groups: mechanical, electrical and fuel / ignition system malfunctions.

Difficulty starting the generator, which manifested itself suddenly and not accompanied by an increase in engine noise, is a clear sign of either deviations in the operation of the carburetor (too lean or rich mixture), or a faulty ignition system (weak or intermittent spark formation). Since the diagnostics of the state of these systems is interconnected, it is combined into one section.

Remove the spark plug and inspect the carbon deposits on the electrodes.

  • Dense and dry black carbon deposits - a sign of a rich mixture (the carburetor is faulty, the air filter is clogged);
  • Oily black carbon - a sign of severe wear of the piston rings, oil enters the combustion chamber;
  • White soot - a sign of running on a lean mixture, it is necessary to check the carburetor.
  • Brick brown carbon deposits - normal for carburetor engines.
  • Red, green-red carbon deposits - a consequence of working on low-quality fuel.

It is simple to check the performance of the ignition system itself because of its extreme simplicity: turn on the ignition, insert a known good spark plug into the plug cap and, putting it on the nearest metal part of the engine with its skirt, turn the recoil starter abruptly. If there is no spark, disconnect the ignition switch and the oil level sensor from the ignition coil in turn: if, when both elements are disconnected, there is still no spark, replace the ignition coil.

If the spark is present and has sufficient strength (white or blue-white), remove the spark plug after several starting attempts. A candle filled with gasoline is a sign of an over-enrichment of the mixture, a dry one is a lack of fuel.

Sometimes, after long storage, the needle and the carburetor float stick and prevent gasoline from flowing inside. Several times sharply, but do not hit the float chamber lid very hard and start again.

The most common carburetor malfunction is contamination. The ingress of dirt into the air channels leads to over-enrichment of the mixture, into the fuel jets - to depletion. Dirt on the float shut-off needle leads to loss of tightness and overfilling of the float chamber, which will be immediately noticeable by the leakage of fuel from the carburetor.

Let's take a look at the carburetor maintenance on the example of a Honda GX engine - its design is typical for a gasoline generator.

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  • Remove the float chamber cover (4). Wash it in gasoline or a carburetor spray cleaner - dirt and deposits accumulate at the bottom.
  • Proceed in the same way with the gas valve sump (22).
  • Check if the gas valve is blown in the "open" position.
  • Take out the float shaft (3), take out the float and the shut-off needle (2). Blow out the channel with air.
  • Blow out the fuel jet (25), emulsion tube (11) and all carburetor passages with an aerosol cleaner or compressed air.
  • Remove the adjusting screw (5), blow out its channel. Then screw it in until it stops and loosen, depending on the type of air filter, by 2 (foam, paper filters) - 2.5 turns (cyclone filters).
  • Assemble the carburetor.

The electrical system of gas generators is quite reliable. Most often, you can face two problems: lack of battery charging on generators with electric start or lack of voltage at the generator output.

  • The lack of battery charging is a consequence of the failure of the rectifier or low-voltage winding.It is easy to check this system with your own hands: connect a 12-volt light bulb in parallel with the low-voltage winding of the generator and start it. A lit light means that the generator itself is working properly, and it is necessary to replace the rectifier.
  • The absence of voltage at the generator output is most often the result of wear on the brushes. Remove them and assess the degree of wear, replace if necessary. If your generator is an inverter type, check if the voltage comes to the input of the converter by connecting a low-power 220 V lamp in parallel with it.

Video about the phased repair of the gas generator