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How to Clean a Carburetor on a Lawn Mower

Authored by Jemma Petts

The backbone of lawn maintenance is a lawn mower. While it’s essential in helping you care for your yard, your job is to keep it in working order. Knowing how to clean a lawn mower and provide regular maintenance is the best way to avoid problems and ensure it delivers lasting performance. This guide will walk you through how to clean each part of your mower, including the:

  • Exterior
  • Mower deck
  • Lawn mower bag
  • Carburetor, both on and off the mower
  • Foam or paper air filter

Read on for all you need to know to keep your mower clean and in good shape, so it continues to perform for years to come.

Read the manual

Before beginning any cleaning or maintenance on your mower, read the owner’s manual for specific details on how to clean your machine. The owner’s manual provides insight into how to secure the fuel tank to prevent spills and can help you steer clear of doing anything that may void warranty claims. 

Safety first 

To protect yourself when cleaning your mower, always wear gloves and safety glasses. To keep your mower from accidentally starting when you’re cleaning it, make sure to:

  • Disconnect (or remove) the spark plug
  • Detach or unplug the battery
  • Perform cleaning in a well-ventilated area, especially when using solvents

Once you’ve read the manual and performed your safety checks, it’s time to get cleaning.

How to clean a lawn mower’s exterior

Keeping the exterior of your mower clean helps ensure a problem-free operation. Grass, dirt, spilled fuel, and fertilizer can all cause corrosion and shorten the lifespan of your lawn mower. Get into the habit of giving it a quick clean after every use by following these six steps:

  1. Fill a bucket with warm water and a multi-purpose detergent.
  2. Use a hose (avoid high pressure) and rinse your mower.
  3. Scrub away grass, dirt and debris using your water/detergent mixture and a non-abrasive brush. 
  4. Rinse the mower’s exterior with the hose. 
  5. Lubricate its spindles, pivot points and linkages with a spray lubricant. 
  6. Let your mower dry before storing. 

Chips in the paint can cause rust. If you notice any while cleaning your mower’s exterior, cover them up with touch-up paint. 

How to clean a mower deck 

Cleaning the underside of your mower helps it cut more efficiently and reduces the spread of lawn diseases. Frequent cleanings can keep your mower fast and easy to use. No matter how often you clean your mower deck during the mowing season, always give it a good scrubbing before putting it away for winter—grass stuck to the underside of your mower for a prolonged period can cause rust. 

Follow these seven steps to clean your mower deck:

  1. Consult your owner’s manual for instructions on how to tilt your mower.
  2. Ensure the spark plug or battery is disconnected.
  3. Fill a bucket with warm water and a multi-purpose detergent.
  4. Spray the underside of the mower with a hose to loosen caked-on grass, dirt and debris. 
  5. Scrub the mower deck using your water/detergent mixture and a brush, sponge or cloth. A hard plastic scraper can also help remove stubborn or hardened grass clippings. 
  6. Rinse and allow the mower to dry completely. 
  7. Reconnect the spark plug or battery. 

Cleaning your mower deck is also a great opportunity to see if your mower blade needs sharpening or replacing.

How to clean a lawn mower bag

Grass clippings and dirt stuck to your mower’s grass bag can lead to foul smells, mildew and mold. It can also shorten the life of your mower.

Follow these six steps to clean your lawn mower bag: 

  1. Remove the grass bag (if detachable) and empty it of all grass clippings. 
  2. Use an air compressor to loosen particles from the bag, turn it inside out and repeat the process. A leaf blower is a good substitute if you don’t have access to an air compressor. 
  3. Fill a bucket with warm water and a multi-purpose detergent.
  4. Rinse the inside and outside of the grass bag with a hose. 
  5. Use a soft-bristled brush and your water/detergent mixture to scrub the inside and outside of the mower bag. 
  6. Rinse the bag again and allow it to dry before reattaching and storing. 

Self-bagging lawn mowers make cleaning up grass clippings easy but, consider ditching the bag and leaving the clippings on your lawn. Most mowers can be converted to a mulching mower blade that leaves behind tiny clippings that quickly decompose and provide moisture and nutrients to your yard.

How do you clean a lawn mower carburetor?

The carburetor is one of the most common culprits of lawn mower stalling, running rough and inefficiently burning fuel. Cleaning a carburetor can feel overwhelming but learning how to clean a lawn mower carb is well within the capabilities of most DIYers.

You have two options for cleaning a carburetor: Keeping it on the mower or taking it off. Typically, whether you leave the carburetor on or remove it for cleaning depends on how dirty it is.

How to clean a lawn mower carb on a mower

Follow these eight steps to clean your carburetor while it’s still on the mower:

  1. Take a photo for reference—it will come in handy when it’s time to put everything back together.
  2. Disconnect or remove the spark plug. 
  3. Remove the outer casing and open the air filter to expose the carburetor. 
  4. Use an air compressor, brush (or combination of the two) to remove clippings, dirt and gunk from the outside of the carburetor and linkage. Take special care to avoid any debris getting into it. 
  5. Spray carburetor cleaner on the carburetor’s outer parts and linkage. Use a brush to remove any stubborn deposits.
  6. Reconnect the spark plug, start the motor and spray carburetor cleaner into and around the center of the carburetor. 
  7. Let the mower run for a minute or two.
  8. Reattach the air filter and outer casing.

How to clean a lawn mower carb off a mower

When preparing to remove and clean your lawnmower’s carburetor, have your phone handy and take pictures for reference—images are handy when it comes time to reassemble the carburetor. 

Follow these 12 steps:

  1. Disconnect or remove the spark plug.  
  2. Remove the cover and air filter. 
  3. Unfasten the fuel linkage.
  4. Detach the fuel line. Have a rag handy to clean up any fuel that spills. 
  5. Unbolt the carburetor from the lawn mower. 
  6. Disassemble the carburetor from the bottom (bowl, float, needle, and main jet).
  7. Clean the individual parts with carburetor cleaner and a cloth. 
  8. Use compressed air and/or a towel to dry the carburetor’s components. 
  9. Reassemble using the photos you took as a guide. 
  10. Re-bolt the carburetor to the mower and reattach the fuel line and linkage. 
  11. Replace the air filter and outer cover. 
  12. Reconnect or reinstall the spark plug.

While your carburetor is disassembled, take the opportunity to replace its gaskets—this is an inexpensive and easy way to save you from future headaches. 

How to clean a lawn mower air filter

The small engines on lawn mowers require a lot of air for optimal operation, which is why most manufacturers suggest regular cleanings. How you clean your lawn mower’s air filter depends on the type: foam or paper. 

How to clean a foam air filter on a lawn mower 

Follow these nine steps to clean a foam air filter: 

  1. Disconnect or remove the spark plug. 
  2. Remove the air filter.
  3. Use compressed air or a brush to remove dirt and debris from the filter housing. 
  4. Wash the filter with a multi-purpose detergent. 
  5. Rinse thoroughly and allow it to dry completely. 
  6. Saturate the foam mower filter with clean engine oil (NOTE: Not all foam air filters require oil. Refer to your owner’s manual for specific instructions).
  7. If oiled, use a cloth to remove any excess—aim for lightly coated, not soaked. 
  8. Reinstall the air filter. 
  9. Reattach or reinstall the spark plug.

How to clean a lawn mower’s paper air filter 

While you can clean lightly soiled paper lawn mower air filters, they’re designed for replacement. Paper air filters are inexpensive and easy to replace, so stock up and keep a few on hand.

Follow these six steps to clean a paper air filter: 

  1. Disconnect or remove the spark plug.
  2. Remove the air filter.
  3. Use compressed air or a brush to clean out its compartments.
  4. Tap the filter with your hand to dislodge dirt and debris. 
  5. Reinstall the air filter.
  6. Reconnect the spark plug. 

A good rule of thumb is to replace paper lawn mower filters every six months or after 300 hours of use. 

Clean or replace? 

Knowing what to clean and what to replace is key for quality lawn mower maintenance and can save you a lot of time and trouble down the road. It’s more cost- and time-effective to replace parts like spark plugs, paper filters, fuel lines, and fuel filters. Instead of taking the time to learn how to clean the fuel line on a lawnmower, it’s often easier and cheaper to just replace it. 

Taking preventive measures can avoid other time-consuming tasks. For example, the best way is to avoid having to clean your mower’s gas tank is to keep the gas from degrading in the tank. Before storing the mower at the end of the season, always empty the tank or add a fuel stabilizer.

You depend on your mower to maintain your yard, and it depends on you to keep it clean so it can perform its best. Knowing how to clean your lawn mower—and doing it regularly—is one of the best ways to keep a clean-cut yard and your mower in top shape.