What to Do When Your Generator Stops Working: 6 Troubleshooting Tips

Reader Contribution by Kayla Matthews
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Photo credit: IStock

Generators can be a handy source of backup power, but there’s nothing like the heart-sinking feeling that comes when you try to use your generator as usual, but experience problems.

Here are six troubleshooting tips to try next time your generator doesn’t work as expected.

1. Check the Spark Plugs

If your generator won’t start, check the spark plugs first and look for signs that they are to blame for the generator’s failure. Excessive wear and damage indicate you need to change the spark plugs. Some warning signs of trouble include heavy carbon buildup at the electrode or evidence that the electrode is burned away or otherwise damaged.

If you have recently changed a spark plug and discovered the generator would not start after that, use a spark plug tester to see if the new spark plug is perhaps defective.

2. Restore the Generator’s Residual Magnetism

Another common problem associated with generators is that they stop producing voltage. Generators function by moving electrical conductors through a magnetic field created when some of a generator’s output voltage gets converted to DC power and fed through a coil, making an electromagnet.

A small amount of magnetism — known as residual magnetism — gets left over from the last time the generator ran. That magnetism produces a modest amount of electricity that creates a stronger electromagnet.

However, a loss of residual magnetism results in your generator not producing any power on startup. You can restore residual magnetism using a 12-volt generator battery or an electric drill. If using the first method, find the voltage regulator on your generator and unplug the pair of wires connected to the generator brushes. One is usually red, and the other is black or white.

Attach the black or white wire to the generator’s ground battery terminal. Then plug in a light, activate the generator breaker or switch and start the generator. Next, connect the red cable to the red wire on the terminals you removed, and keep it there for three seconds. Finally, remove the wires and replace the plug.

Or, you can use an electric drill to restore the residual magnetism. If you’re using a reversible drill, set the directional switch to the forward position. Start the generator and hold down the drill’s trigger as you spin the drill’s chuck in the reverse direction. This tactic allows the electric motor in the drill to act as a small generator, helping to restore the residual magnetism to make your generator produce power again.

3. Clean the Generator’s Carburetor

The carburetor is a generator component that mixes fuel with air when you start the machine. Since fuel and oxygen are two of the things generators need to run properly, any problems related to starting the generator could be due to a dirty carburetor. Commercial generator servicers frequently offer fuel system cleaning as an option clients can avail themselves of to keep their generators running smoothly or customize them to meet defined needs.

Similarly, cleaning the carburetor could fix issues caused by fuel remnants gumming up the generator’s components and affecting its fuel intake. After you remove the generator’s carburetor and become familiar with its parts, you can treat the affected areas with a specialty carburetor cleaner. Many options come in spray formulas for easy application.

4. Look for Signs of a Pest Infestation or Water Damage

When a generator operates abnormally, it could be due to pests or water getting inside the machine. Those possibilities are more likely if you store your generator outside in an unsheltered, non-enclosed area. Animal droppings inside the generator and gnawed areas are a couple of telltale signs concerning pest issues.

Or, if water is the culprit, you’ll likely see excessive moisture inside. It’s imperative to see if the water damage affected the generator’s engine core or its electrical components. Once you verify which areas got wet, you can start investigating the issue further and determining if you can salvage the generator or need to replace it.

5. Put Fresh Fuel Into the Generator

One of the most common and easy-to-fix reasons for a portable generator that won’t start, as well as a larger one, is that there is old gas in the tank.

Some people get used generators from friends or peer-to-peer marketplaces like Craigslist and try to immediately fire them up to test their purchases. Or, they try to start the generator after a season or more of disuse and forget they left fuel in the tank before storing it.

Both of those scenarios can cause the generator not to start because there is sludge in the bottom of the tank and other problems that happen when fuel sits too long in an unused machine. Start by looking at the fuel in the tank and seeing if it appears separated or cloudy. Those are two signs of old fuel.

If fuel is likely the issue, remove the old liquid with a siphon. Then, put fresh gas in the tank and try to start the generator.

6. Understand the Generator’s Output and Don’t Overload the Machine

When your generator starts normally, but turns off after running for a while, you may assume there’s a fault with the machine. Before jumping to that conclusion, though, check the generator’s output rating to make sure you are not trying to power too many appliances at once.

Overloading a generator can damage the things you run with it, such as computers. And, overloaded generators can shut off without warning after the circuit breaker trips. Refer to the documentation that came with your generator to get information about its output capabilities, and always be careful not to run too many things at once.

Start Diagnosing the Problem With These Tips

A generator that doesn’t work as expected can become a hassle if you get overwhelmed and believe you don’t know where to start with trying to fix the problem. By following these troubleshooting guidelines, you can get to work locating the problem and solving it.

Kayla Matthews has been writing about healthy living for several years and is proud to be a featured writer on a number of inspiring health sites, including Mother Earth News. To learn more about Kayla, you can follow her on Google+, Facebook and Twitter and check out her most recent posts on ProductivityTheory.com.


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