Flooded Lawn Mower Engine Symptoms

You may want to start your lawn mower, but the engine fails to start. This could result from a flooded engine. We know how frustrating it gets; therefore, we created this article to help you solve the problem. The article has flooded lawn mower engine symptoms and tricks you can fix the problem.

If you don’t know the common flooded mower engine symptoms, it will be tough for you. Testing the engine requires you to turn the gas on, give the machine a choke or tug the pull starter rope. After a few minutes, you may smell gasoline from the carburetor. Well, that is enough indication that your lawn mower is flooded.

Many beginners find it a hassle to deal with a flooded lawn mower. But experienced users come across the problem once in a while. Today, we have highlighted the tips for identifying a flooded lawn mower and how to start it.

Let us explore:

Flooded Lawn Mower Engine Symptoms

A flooded lawn mower is when there is excess fuel inside the carburetor. The fuel will go to the carburetor, thus affecting the lawn mower’s performance. A spark plug is essential in fuel combustion and air mixture for the engine to start and run.

The best way to test for a flooded engine is through a sniff test. You can do that by setting the choke high or over-prime before starting the machine.

After pulling the cord while starting the engine, flooded fuel in the carburetor will not provide enough oxygen – an element used to feed combustion.

The engine will not start, but hear gurgle out that dies instantly, where the smell of gasoline will rise and hang in the air. You can easily detect the smell, particularly on a warm day.

Other Considerations

A lawn mower engine flooding may result in different ways. A blocked carburetor outlet will trap fuel inside, while dirty air filters limit air intake, leading to frequent engine flooding.

When the spark plug points rust, they cause misses, thus allowing the fuel mixture in piston chambers and into the carburetor. Spark plugs and air filters can be replaced and clean the carburetor ports.

Also read: How do you fix a lawn mower that won’t stay running?

signs of a flooded lawn mower

Also read: What engine oil should I use in a Kawasaki mower?

How to Unflood a Lawn Mower

It is common to have trouble starting a gasoline-powered lawn mower, particularly after staying in cold and damp conditions.

Move your lawn mower to a dry area and start the cord with several tugs. After not receiving any response, turn on the choke, continue to pull, and you will detect a gasoline smell. So, that will mean you have a flooded engine.

Here is how to unflood a lawn mower:

Things You Have to Use

  • Dry cloth
  • Starter fluid
  • Spark plug wrench
  • Screwdriver

If you want to solve the problem, the convectional remedy for such a lawn mower engine is to allow it to sit for about 15 minutes. The time will give the carburetor enough time to dry.

Fortunately, there are other quicker solutions for a flooded lawn mower engine.

The other thing is pulling off its spark plug wire and using a wrench to unplug the spark plug. This is done because the plug terminals are likely moistened with gasoline. You have to dry them by spraying alcohol starter fluid or wiping them with a dry cloth.

When done, crank the engine twice or more without the plug to help it draw air via the carburetor, and it will dry out. Take the spark plug and replace it; turn the choke off and crank the engine.

When the engine sputters, continue to crank until it starts. Sometimes, you may have to turn the choke back and allow it to turn over. Once the engine starts, now turn the chock off.

The other method is removing the air filter once the engine doesn’t sputter. You can locate the filter at the side or top of the lawn mower. If you’re to remove the filter, you need to have a screwdriver.

When you get the filter, spray it with starter fluid, insert it back, and crank the engine. If there is no response, remove the air filter again and crank the engine to help empty the carburetor. Perhaps the engine turns over or sputters without the filter; that will mean the air filter is dirty, and you should replace it.

Also read: Oil extractor pumps for mower


  • If the lawn mower will not start and there is no gas smell, you could have turned the fuel valve off or no gas left in the tank.
  • Gas will go bad when the mower is left idle for a long time. You will have to siphon it out and replace fresh gas before you start the engine

How can you tell if you got bad gas in the mower?


Ensure all sources of flame are far from the mower during service. The gas fumes are flammable, which means they could catch fire.

FAQ: signs of a flooded lawn mower

How will I know my mower engine is flooded?

Pull your lawn mower on the lawn and give the start cord a few tugs. After nothing happens, turn on the choke, pull, and then detect the gasoline smell. That will indicate the engine is flooded and will not start without unflooding.

Also read: best lawn mower lifts for riding mower

What will happen with a flooded lawn mower engine?

When the air filter has much gasoline-soaked, it will prevent airflow in the engine. The fuel may also find its way into the spark plug where it wets the point, thus no spark. In all these situations, the lawn mower will not start. That’s because of the permanent damage caused.

Also read: Riding mower sputters and backfires when trying to start

How long will it take before the flooded engine dries out?

The best remedy when you have a flooded engine is to give it time. You have to allow the fuel to evaporate. After 30 minutes, try to start the lawn mower again.

The next time you see flooded lawn mower engine symptoms, don’t worry about it. The above article has detailed information on determining flooded engines and solving the problem.

Also read: What happens when lawn mower overheats?

You have to worry about your lawn mower when it shows aging signs. You will need to seek professional help.

Leave a Comment

Your email address will not be published. Required fields are marked *