Why Is My Generator Sputtering?

Generators are a reliable source of power, and it can be frustrating when they start to sputter. Whether you’re using it for camping or as a backup power source, a generator that’s sputtering could affect your plans. In this section, we’ll explore the common reasons why your generator might be sputtering and provide you with troubleshooting tips to optimize its performance.

Key Takeaways

  • Generator sputtering can be caused by a variety of issues.
  • Common causes of generator sputtering include a lack of fuel, clogged air filters, spark plug problems, and other factors.
  • Troubleshooting these issues can help you optimize your generator’s performance and prevent future sputtering.

Lack of Fuel or Fuel Issues

Is your generator sputtering due to lack of fuel or fuel issues? This is a common cause of generator problems and can quickly be resolved with a few troubleshooting steps.

The first thing to do is to check that there is enough fuel in the tank. If the fuel level is low, refill the tank. If the tank is full, but the generator is still sputtering, there could be an issue with the fuel supply. Check the fuel lines and filter for any blockages or damage. If you notice any problems, replace the damaged components.

Another potential fuel issue that can cause sputtering is the quality of the fuel being used. Old or contaminated fuel can clog the carburetor and cause issues with combustion. Consider draining and replacing the old fuel with fresh fuel to see if this resolves the issue.

Lastly, make sure to take regular care of your generator by using high quality fuel and keeping the fuel tank and lines clean to prevent future sputtering due to fuel issues.

Clogged or Dirty Air Filter

A clogged or dirty air filter can cause your generator to sputter or even shut down. The air filter prevents dirt, dust, and debris from entering the engine and affecting combustion. Over time, the filter can become clogged with dirt and hinder proper airflow, leading to sputtering.

To check if your generator’s air filter is clogged, remove the filter cover and take out the filter. Hold the filter up to the light and check if you can see through it. If it appears dirty or clogged, it’s time to clean or replace it.

To clean the air filter, use compressed air or a soft-bristled brush to remove any debris. If the filter is severely clogged, it’s best to replace it entirely. Refer to the owner’s manual or manufacturer’s instructions for the specific type and model of air filter needed for your generator.

Regular maintenance is key to preventing a clogged or dirty air filter. Clean or replace the air filter every six months or after every 100 hours of use.

Spark Plug Problems: Troubleshooting Generator Sputtering

If your generator is sputtering, one common cause is spark plug problems. Faulty or worn-out spark plugs can cause irregular combustion, leading to generator sputtering.

To troubleshoot potential spark plug issues, you should first check the spark plug for damage or wear. Look for signs of erosion, such as a worn electrode or insulator, or buildup of carbon deposits. If the spark plug appears damaged, it should be replaced.

Next, check the spark plug gap. To do this, use a wire feeler gauge to measure the gap between the center electrode and ground electrode. The gap should be set to the manufacturer’s specification, which can be found in the generator’s manual. If the gap is too large or too small, it can affect the spark plug’s performance and cause sputtering.

If the spark plug appears undamaged and the gap is correct, but the generator is still sputtering, you may need to clean the spark plug. This can be done using a wire brush or spark plug cleaner. Be sure to follow the manufacturer’s instructions and wear protective eyewear and gloves when cleaning the spark plug.

To prevent future spark plug problems and generator sputtering, it’s important to perform regular maintenance. This includes checking the spark plug gap, cleaning or replacing old spark plugs, and using the correct type of spark plug for your generator.

By troubleshooting and addressing spark plug issues, you can help ensure reliable power generation from your generator.

Other Possible Causes of Sputtering

While lack of fuel, clogged air filters, and spark plug issues are the most common causes of generator sputtering, other factors can also contribute to this problem.

A faulty carburetor can restrict fuel flow to the engine, leading to sputtering. If you suspect the carburetor is the issue, check for dirt, debris, or corrosion buildup and clean or replace as necessary.

Low engine oil level can cause irregular engine function and result in sputtering. Regular oil changes and level checks can help prevent this problem.

Electrical problems, such as a weak battery or faulty alternator, can also cause sputtering in generators. If you suspect an electrical issue, consult the generator’s manual for troubleshooting guidance or seek professional assistance.

When troubleshooting other potential causes of generator sputtering, it’s essential to follow safety procedures and adhere to the manufacturer’s instructions. If you’re unsure about how to proceed, don’t hesitate to seek advice from a certified technician.


Generator sputtering can be frustrating and disruptive, but it’s usually a solvable issue. By troubleshooting the common causes of sputtering, you can often identify and fix the problem without professional help. Ensure that you regularly maintain your generator to prevent future sputtering and extend its lifespan.

We hope that the tips provided in this article have helped you to diagnose and troubleshoot your generator’s sputtering issues. Remember to check for fuel problems, clean or replace your air filter, inspect your spark plugs, and look for any other potential causes of sputtering. With proper attention and maintenance, you should be able to keep your generator running smoothly and reliably.