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What To Do When a Generator Keeps Flooding

What To Do When a Generator Keeps Flooding

Generators are a handy tool and can help you save on electricity bills. However, generators can sometimes present challenges such as engine flooding. If you are experiencing such issues with a generator engine, you might wonder what you can do?

If your generator keeps flooding, you should dry the spark plugs of any excess fuel preventing them from igniting. You should crank the system a few times to dry the carburetor and consider a carb clean and fuel change. Finally, check that your choke lever is open once you start your engine. 

You can tell a flooded generator engine by checking if the spark plug is wet or if the engine keeps stuttering without igniting. Both signs indicate that the engine is faulty and requires fixing. Keep reading this article to determine how to resolve this issue, what causes generator engines to flood, and the best way to prevent flooding.

Fixing a Flooded Generator

Generators use varying engines of different specifications depending on the type. Therefore, you should consider visiting a professional technician for assistance should DIY engine fixes fail or seem complicated. You should also exercise caution during the repair to prevent explosions and fire outbreaks from inadvertent fuel leakages.

Here are a few steps you should take to fix a flooded generator:

  1. Dry the Generator Spark Plugs

After noticing a flooded generator, you should consider drying the spark plugs. Flooding usually causes excess liquid fuel to rush into the engine, which wets the spark plugs, preventing them from igniting. Therefore, drying the spark plugs allows combustion, burning the fuel, and starting the generator. 

To dry the spark plugs, blast the engine components with compressed air from a hose, hairdryer, or vacuum cleaner. In cases involving small generators, you can let the generator sit while the spark plugs dry. However, this is a slow process. 

You should also consider replacing the spark plugs with new ones if they are faulty and you have not replaced them in a long time. 

  1. Crank the Generator System a Few Times

Consider cranking your engine a few times to see if it solves the problem. Cranking the system without the spark plugs allows air to get in and dry the carburetor. You can return the spark plugs after this and try restarting the generator.

  1. Replace the Generator Fuel and Clean the Carburetor

Another step you should consider is replacing the fuel. Low-quality fuel often causes gummed fuel and debris to build up in the carburetor, thus leading to flooding. Replacing the fuel lets you clean the system and remove fuel deposits and debris before adding fresh fuel. 

Do not forget to thoroughly clean the carburetor because a dirty carburetor also causes problems like hesitation, stalling, flooding, and hard starting. Remove the air filter housing it while the engine is off and spray a carburetor and choke cleaner to clean the carburetor. I must also emphasize that the replacement fuel you use should be top quality.

  1. Open the Generator Choke Lever

Check if the choke lever is open, as this is a common reason generator engines flood. Ideally, the choke lever should remain closed when the engine starts the ignition process but open after it heats up to allow airflow into the system. 

The air mixes with fuel in the combustion chamber and ignites, allowing the generator to start. Leaving the choke lever closed while repeatedly igniting the engine causes flooding as additional fuel, and no air enters the combustion chamber.

If these fixes fail and the generator keeps flooding, you should consult a professional for further assistance. The technician will resolve the flooding issue, restoring your generator’s performance (source).

Factors That Cause Generators To Keep Flooding

Various issues allow excess fuel to flow into the combustion chamber, flooding and wetting the spark plugs. These include (source):

  • Over-priming occurs when one pumps excess raw fuel into the engine cylinders, leading to flooding.
  • Restarting an automatic choke engine immediately: Every time the engine attempts igniting, it pumps a small amount of fuel into the combustion chamber. Restarting an automatic choke engine causes fuel buildup from the repeated injection, causing flooding and inhibiting ignition. 
  • A closed choke: The primary purpose of the choke is to restrict airflow and maintain a healthy fuel-air balance that sustains combustion. Usually, the choke should be closed when the engine starts the ignition process and open once the engine is warmed up. Closing the choke leads to fuel buildup without enough air to burn it up.
  • A gummed carburetor: Gummed carburetors result from a buildup of fuel residues due to many factors, including low-quality fuel or an improper fuel mixture. 
  • Stuck valves: Stuck valves are standard in cold weather and during the morning and often loosen up as the engine heats up. Oil sludge, rust, and carbon deposit buildup may contribute to this issue. 

Safety Precautions When Fixing a Flooded Generator

People should observe various safety precautions when fixing flooded generators. For example, you should power off the generator before disassembling it. Otherwise, you risk a fire accident. Keep any flame sources away from your work area because you’ll be handling flammable fuels.

It is also advisable to use the right tools to avoid damaging your generator’s engine. Do not use force to open engine components because you may harm them, necessitating unnecessary repairs. You do not want to deteriorate your generator’s condition when all you want is to fix the flooding.


Always fix your generator engine carefully with adequate protective gear. You should always prioritize your safety and your loved ones by seeking professional advice should you suspect you are ill-equipped for DIY flooding generator fixes. 

In addition to hiring professionals to fix the issues, you should perform regular maintenance checks since that is the best way to prevent repeat generator flooding.

Finally, you should avoid harmful practices such as repeatedly starting and stopping a generator engine without ample time for the engine to burn and eject excess fuel.

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