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How to Fix a Generator? – 10 Common Issues & Fixes

How to Fix a Generator
Written by Jamie Masterson

A broken generator is a headache that needs to be solved immediately. Generators are usually used when there’s no power on the grid, so when it goes out, you’re left in the dark.

Here we’ll be going over the various ways your generator can break down and show you how to fix them.

How to Fix a Generator?

1. Runs but no power

If the engine is running but producing no power, there’s a good chance your AVR has shorted out. An AVR regulates the voltage of the power a generator produces.

When you run a generator, it produces electromagnetic interference. A generator that runs for a long time will produce a lot of interference, which can lead to the generator underproducing power. The AVR will overwork trying to compensate, leading to a short. If the generator is running at less than 5 volts, you will need to replace the AVR.

Step 1: Grab a wrench and a screwdriver.

Step 2: Remove the side panel of your generator using the screwdriver. Some generators’ AVRs are installed in the motor section.

Step 3: Detach all of the cables from the AVR, then remove it.

Step 4: Place your new AVR in the space, then reattach the cables.

Step 5: Run your generator and use a meter to make sure the voltage is correct.

2. Battery failure

Battery failure is the most common cause of generator malfunction. There are a few things you will need to check on your battery.

Step 1: You will need a meter, a wrench, and something to clean the corrosion off of the battery terminals.

Step 2: Use your meter to measure the voltage from the battery. If it is low, then the battery is the problem.

Step 3: Detach the terminals from the battery with the wrench.

Step 4: Clean the corrosion from the battery and the terminals.

Step 5: Reattach the terminals to the battery.

Step 6: Read the voltage with the meter. If it is still too low, you will need to replace the battery.

How to Replace the Battery?

3. Coolant leaks

When the coolant leaks, it can lead to irreparable damage to the whole generator. The most common places coolant leaks occur are in the radiator and the block heater hoses.

Before starting repairs, make sure your generator has been off for a while. There is a pressure cap on the seal of the radiator. If you try to open it while everything’s still hot, the pressure can cause serious damage.

Step 1: Use a pair of heat-resistant gloves.

Step 2: Remove the cap seal on the radiator.

Step 3: If the coolant level is low, add more coolant. Do not overfill the tank.

Step 4: Check the block heater hoses. They will be attached to the back of the radiator. If there is any damage or if they are warped, you will need to replace them.

Step 5: Attach the new hoses.

4. Low fuel level

A generator needs fuel to run. If the fuel level is low, the generator will overcompensate to get the most power. Luckily, this is an easy fix.

Step 1: If you have an empty fuel canister, fill it with gas.

Step 2: Open the fuel cap.

Step 3: Pour in the gas.

Step 4: Check your gas meter. If it shows that no gas has been added, there’s a problem with your fuel meter.

5. Dirty air filter

Dirty air filters will add foreign particles into the gas line, which can make your engine’s fuel input and power output inefficient.

Step 1: Switch your fuel valve to “off.”

Step 2: Twist the knob at the bottom of your air filter assembly and remove the cover.

Step 3: The filter is the sponge like square in the assembly. If it is dark and oily, it’s time to replace it.

Step 4: Insert the new air filter.

Step 5: Close the cover of the assembly.

6. Clogged carburetor

Old gas can build up in the carburetor of your generator. This build-up can clog the carburetor, causing fuel to burn faster. You will need to buy a can of carburetor cleaner. The cleaner is a very powerful, sometimes dangerous solvent that will cut away any dirt or gas stuck in the carburetor.

Step 1: Get eye and hand protection, the carburetor cleaner, and a metal container to put the cleaner in.

Step 2: Remove your carburetor from the motor.

Step 3: Apply the cleaner on all of the parts of the carburetor.

Step 4: Wait for your carburetor to dry, then reinstall it.

7. Oil Pressure sensor malfunction

When the oil pressure sensor malfunctions, you get inaccurate readings of oil temperature and amount. This can lead to overfilling the oil or smoke coming from your engine. To replace your oil pressure sensor is malfunctioning, do the following steps.

Step 1: You’ll need a socket wrench, and a set of pliers.

Step 2: Lift the car, then drain the oil completely. This may take several hours.

Step 3: Once the oil’s drained, disconnect the sensor’s wiring harness.

Step 4: Using the wrench, disconnect the sensor from the housing.

Step 5: Install the new sensor into the housing. Don’t tighten too much.

Step 6: Reattach the housing. Use your pliers to handle the wires.

Step 7: Tighten the housing with the wrench

Step 8: Refill the oil pan, then turn on the generator.

Step 9: If your oil meter is reading correctly, you’re good to go.

8. Fuel leak

Leaks of any kind can spell doom for your generator, but fuel leaks are particularly bad. They cause fires, explosions, and toxic air. Most fuel leaks come from the fuel lines, so we’ll be looking at how to replace the fuel lines of a generator.

You will need to know the fuel line mapping of your generator. Installing the lines incorrectly will lead to engine failure.

Step 1: Before you begin, you will need a screwdriver, a socket wrench, and a set of pliers.

Step 2: Remove the air filter assembly.

Step 3: Use your pliers to remove the tube connected to the carburetor.

Step 4: Remove the gasket.

Step 5: Detach the carburetor from the regulator by taking the pliers and moving the two rods behind the carburetor.

Step 6: Pull the carburetor out.

Step 7: Take off the rubber fuel lines and add the new ones on.

Step 8: Put the carburetor back in its housing and re-attach all of the loose parts.

9. Spark plug needs to be replaced

If you’ve got a bad spark plug, you won’t get the proper kick to start the generator’s engine. Spark plugs are easy to get and not very expensive, so replacing them is a breeze.

Step 1: You will need a socket wrench to replace the spark plug.

Step 2: Pull off the boot of the spark plug with your hand.

Step 3: Take your socket wrench and loosen the spark plug, then remove it.

Step 4: Put in the new sparkplug

Step 5: First, tighten it with your hand, then switch to the socket wrench to make it tight. Be careful when tightening, because the spark plug will break if tightened too much.

10. No spark


Q. Do I need an electrician to connect a generator?

An electrician will know how the power grid of your house is wired. To install a generator properly, you will need to install it in the correct place. An electrician will be a big help with that.

Q. Can Christmas lights overload an electrical circuit?

Most electrical circuits are built to provide power for home appliances. Christmas lights take a lot of power, which will cause strain on the electrical circuit, sometimes leading to power outages.

About the author

Jamie Masterson

With decade-long experience as a generator technician, Jamie has worked with USA’s top generator manufacturers and suppliers as an independent contractor.

The long years of service to the industry has taught Jamie the ins and outs of troubleshooting, repairing, and maintaining all kinds of generators in home, industrial and outdoor settings.

Jamie thinks this platform is a great opportunity to share his tips and tricks with you so you can make the most of such power equipment for better living.

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