Lawn mower engine degreaser. How to Clean a Lawn Mower Carburetor for Annual Maintenance

Knowing how to locate and clean the carburetor on your lawn mower can keep it running smoothly for years to come.

By Timothy Dale | Updated Jun 3, 2022 11:19 AM

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How To Clean a Honda Style Carburetor (Step-by-Step)

A common problem encountered by many homeowners is finding that their lawn mower engine won’t start when they try to mow after a long winter season. This can be a sign that your mower’s carburetor is gummed up or even corroded, so it’s important to perform annual maintenance at the beginning of the mowing season to address any problems that could have been created over a long period of disuse.

Other signs of a dirty or restricted carburetor include the engine starting but stalling during use, the muffler emitting black smoke, a significant increase in fuel consumption, or the engine running rough during regular use. Keep reading to find out how to clean a lawn mower carburetor, as well as how to diagnose if you need lawn mower carburetor cleaner or more involved carburetor repair.

  • Screwdriver
  • Needle-nose pliers
  • Nut driver
  • Socket set
  • Gloves
  • Carburetor cleaner
  • See full list «
  • Bucket
  • Compressed air

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In the event a dirty carburetor isn’t the reason your lawn mower won’t start, it’s important to first make sure something else isn’t causing the issue. Double-check that there’s fuel in the tank, the fuel valve is on, and the spark plug is in decent condition before spraying aerosol lubricant or carburetor cleaner into the throat of the carburetor. After spraying the carb cleaner, attempt to start the engine. If the engine runs at all, then the issue is with the fuel system. If the engine refuses to start after several tries, however, then the problem may be more serious. In that case, take your mower to a small engine repair shop.

STEP 1: Clean the outside of the lawn mower engine.

The purpose of learning how to clean a carburetor on a lawn mower is to remove any dirt and debris that could be causing the engine to run rough, so begin the lawn mower carburetor cleaning process by cleaning the outside of the engine while it is turned off. This makes it easier to keep the internal parts of the carburetor clean during disassembly.

Also, it’s necessary to take the time to clean your work area, which should be well-lit to avoid losing any small parts while you work. Have a clear space on your workbench where you can disassemble, clean, repair, and reassemble the various parts of the carburetor.

STEP 2: Remove the air filter to access the carburetor.

In order to access the carburetor in your lawn mower, you need to remove the air filter housing. The air filter typically sits overtop of the carburetor. Inspect the air filter to determine if it’s attached with clips or screws, then use a screwdriver to loosen the fasteners and place them in a safe location for reinstallation. Next, remove the air filter. It’s a good idea to inspect the air filter and either clean or replace it if necessary. If you have difficulty removing the air filter, you should be able to find detailed information in your lawn mower’s manual to help with this part of the process.

STEP 3: Remove the carburetor.

Wearing durable gloves for skin protection, use a carburetor cleaner for lawn mowers to spray into the throat of the carburetor or clean the part’s exterior. To clean the internal pieces of the carburetor, though, you will need to remove it entirely from the engine. Use a nut driver or socket set to remove the two bolts that hold the carburetor to the engine, then disconnect the throttle and choke linkage cables from the carburetor.

Make sure to place any fasteners or small pieces in a safe location for reinstallation, and note (or photograph) the location of any cables or hoses so you can put them back in the proper place. Prepare a bucket or bowl to catch the fuel before removing the fuel lines from the nipples of the carburetor housing with needle-nose pliers. If no gas comes out of the fuel line, you may have a plugged fuel line or fuel filter, which will have to be addressed before reassembling the lawn mower.

Once the carburetor is disconnected, pull it off of the mounting studs, taking care to avoid damage to the main gasket between the carburetor and the engine. Also, make a note of the position of the carburetor so that you don’t reinstall it upside down. Place the carburetor in a bucket to allow any fuel to drain.

STEP 4: Disassemble the carburetor.

A key reminder before disassembling your carburetor is that every piece you remove needs to be put back in the same position. Prepare an appropriate place to disassemble the carburetor if you haven’t already, and consider taking pictures while you work to prevent confusion during reassembly.

With the carburetor in the middle of your clean work area and while wearing gloves, start the disassembly process by cleaning around the bowl with a carburetor cleaner. Next, unbolt the fuel bowl and ensure the hole in the nut is clear of any obstructions by poking a paper clip or piece of thin wire through it. Then, remove the float, which should be attached to the carburetor with a hinge pin, and also remove and replace the needle, if necessary. Keep all of the parts grouped together.

STEP 5: Replace any worn-out parts.

Even the best carburetor cleaner cannot repair worn-out parts. Should you spot significant wear and tear on any parts, including the float, pin, needle, or gaskets, then you should get a carburetor repair kit for your specific carburetor to make necessary repairs. Some carburetor parts, like gaskets, wear out more quickly than other parts. When planning your annual carburetor cleaning, it’s recommended to have spare parts ready on hand to avoid taking the carburetor apart more than once. Simultaneously replacing the mower air filter also helps to streamline the maintenance process.

STEP 6: Clean the carburetor and carburetor parts.

With the carburetor disassembled and your gloves on, you will be able to spray carburetor cleaner inside the carburetor housing and clean the various parts. Carb cleaners come in aerosol cans that are great for quick, efficient cleaning, but you can also purchase carburetor cleaner in a bottle or jug.

If you prefer to use a liquid carburetor cleaner over a spray cleaner, then you will need to pour the cleaner into an empty bucket where the parts can soak. Wire the larger parts of the carburetor together, then carefully lower them into a bucket filled with carb cleaner. Use a piece of aluminum screen or a fine-mesh basket to wrap the small pieces of the carburetor before placing them in the bucket, as well. Leave the parts to soak for about an hour before removing them from the cleaning solution.

STEP 7: Reassemble the carburetor.

Rinse the carburetor parts with water to remove excess carburetor cleaner. Then, blow dry the parts with compressed air or let them air dry. It’s essential that the parts are completely dry before reassembly.

When you’re confident that the carburetor parts are dry, you can begin putting the carburetor back together. Use any pictures you took during disassembly to ensure that you are correctly reassembling the parts.

Once the carburetor is reassembled, mount it on the lawn mower, reattach the throttle and choke linkage cables, and reinstall the fuel lines. Fasten the bolts on the carburetor and reattach the air filter to the mower.

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STEP 8: Test the lawn mower.

After you have reassembled and reinstalled the carburetor and air filter, add fuel to the gas tank and start the lawn mower to ensure that the maintenance was a success. Ideally, cleaning the carburetor should allow the engine to start up easily, but if you continue to experience problems with starting your mower, take the lawn mower to a small engine repair shop for further diagnosis.

Final Thoughts

To get the longest life possible out of your mower, it’s necessary to perform regular maintenance throughout the year. This includes cleaning the carburetor at the beginning of the mowing season, winterizing your lawn mower at the end of the mowing season, and changing oil, replacing spark plugs, and sharpening blades as needed. If you neglect regular mower maintenance, it may break down in a relatively short period of time, costing you more in expensive repairs.

Don’t Google small engine repair near me the next time your lawnmower sputters. Learn how to do it yourself. Small engine repair is all about a clean carburetor.

Family Handyman


Solve most lawnmower or other small engine starting problems with a simple diagnosis and a carburetor cleaning or rebuilding. It will only take a few hours, and you’ll avoid the minimum 80-plus-parts repair bill.

Materials Required

If you can’t get a small engine started, it takes too many pulls to get it going, or it runs poorly, ask yourself this: Did it sit for a long time with gas in it? Like over the winter? If so, your problem is most likely a corroded or gummed-up carburetor. Small engine repair shops earn about 50 percent of their revenue by cleaning or replacing carburetors sidelined by old gas. Look at your lawnmower carburetor next time you sharpen the blades or complete a lawn mower tune-up.

Before you start taking things apart, take a minute to confirm the carburetor is the problem. We’ll show you how to do that, as well as how to clean, rebuild or replace a lawnmower carburetor. Either way, you’ll save about an hour of shop labor (about 80). You can complete the carburetor rebuild project in a single morning, including the time scouting for parts.

How to Find Lawn Mower Carburetor Parts and Prices

Whether you buy parts from a local small engine repair shop or online, you may need all this information:

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  • Machine brand (Toro, Snapper, Honda, etc.), model and serial number.
  • Engine brand and serial number (Tecumseh, Briggs Stratton, Honda, etc.). The engine model and serial number are usually located on a plate above the spark plug.
  • You may also need numbers from the old carburetor itself, usually stamped onto the carb body or its mounting flange.
  • You can buy locally, or try or

Where is the Carburetor on a Lawn Mower?

The carburetor is usually located towards the top of the engine, and is connected to the gas tank.

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Lawn Mower Carburetor: When and How to Clean

Few pieces of home maintenance equipment work as hard as your lawnmower. Despite its rough-and-tumble life, though, many lawnmowers don’t get the care and attention they need.

This is especially true when it comes to the lawnmower’s carburetor. Your lawnmower’s carburetor is a critical component for functionality and will be the thing that determines whether your lawnmower works for years or conks out early.

With that in mind, learning to clean your lawn mower carburetor is a critical part of preventative maintenance. Here’s what you need to know.

When Should you Inspect and Clean a Lawnmower Carb?

While the exact recommendations for this vary from household to household, most experts say you should check and clean a lawnmower carb at least a few times a year.

The reason for this is simple: as you use your lawnmower, the grass, twigs, and debris the blade kicks up make their way into the small engine. Some of that debris eventually wind up inside of the carburetor – clogging fuel and air passages and reducing the performance of the mower’s engine.

Steps to Clean a Carburetor

Here are four steps to follow to clean your carb quickly and easily:

Start by Checking Your Air Filter

The first step in cleaning the carburetor is to check the air filter to ensure it’s free of debris. A clogged air filter will create black smoke that spills from the exhaust. It will also make it difficult for your carb to get the air it needs to “breathe.”

Check all Connections

Next, it’s time to check the connections that run from a carburetor’s throttle and choke plates, since these things can stick when they get dirty.

Additionally, constant vibration and wear can loosen screws over time, contributing to strange handling and additional carb issues.

Use Carburetor Cleaner

Next, it’s time to pick up a carburetor cleaner to get rid of the deposits within the carb, which can clog both air and fuel passages and interrupt the performance.

Fortunately, you can generally do this without even taking the carburetor out of the engine. Start by purchasing some commercial lawnmower carburetor cleaner, which comes in a simple spray can and will make it easy to clean the inside and outside of the carb.

After you’ve coated the surfaces of the carb with this cleaner, give the lawnmower a once-over for other maintenance issues, like stale fuel, bad air filters, old spark plugs, dirty engine oil, and more.

Check Settings

Now it’s time to check the settings on your carburetor to see if anything should be adjusted or updated.

If you’re not sure what you’re looking for, take your carburetor to a local repair service, which can help you identify issues and ensure you’re running your carb as efficiently as possible. This professional will also be able to help you understand why you shouldn’t drain the fuel and how best to care for your lawnmower in the future.

Keeping Your Carburetor Clean and Healthy

A critical piece of your engine’s functionality, the carburetor keeps your lawnmower running strong and functioning well. When you understand how to clean your lawnmower carburetor, you can keep your lawnmower in great shape for years to come, no matter how hard you use it.

The Best Engine Degreasers to Keep That Engine Bay Clean

Even if you regularly clean the interior and exterior of your vehicle, there is a good chance that you do not clean your engine. Many people don’t attempt to clean their engine bay because the dirt and grime is often far tougher than anything that accumulates on the body or the interior carpeting. Your average all-purpose cleaner won’t remove burned-on oil from around the edges of your valve covers or the dirt that is cooked onto the top of the engine cover. That is where an engine degreaser comes into play.

Cleaning the gunk on your engine takes a special product that is made to eat through the mixture of dirt and oil that has been baked at high temperatures for long periods of time. Removing grime like that requires a specially formulated engine degreaser that will break down and loosen under-hood filth.

If you are obsessive about the cleanliness of your vehicle and you know that the engine bay requires a special cleaner, you may be unsure of which to select. Whether looking online or at your local parts store, there are many brands of engine degreasers on the market. In this article, we hope to make shopping for the best engine degreaser a bit easier, so you can get to cleaning that dirty ‘ol engine bay.

For more information on the best engine degreasers, refer to our table of contents.

Editor’s Pick: Chemical Guys Signature Series Orange Degreaser

Chemical Guys Signature Series Orange Degreaser uses a citrus-based formula to remove grease, grime, dirt, and other debris that accumulates in your engine bay. While it is designed to be used to break down baked-on mixtures of dirt and various lubricants, it can also be used to loosen grime on the wheels and undercarriage areas of your vehicles. If you get road tar or other sticky materials in your wheel openings, the Chemical Guys Signature Series Orange Degreaser can help remove it quickly. You can even use it on tools or on your garage floor, all of which can gather similar gunk to that found in an engine bay.

Using the Chemical Guys Signature Series Orange Degreaser is simple. You spray it on the affected area and wipe it away. In areas with thicker grime, you may need to add a little elbow grease. In areas where it is safe, including the wheel wells or select areas around the engine bay, you can put down a thick layer of Chemical Guys Signature Series Orange Degreaser, let it soak a bit, and rinse it away with water.

In addition, to knocking out tough dirt, the Chemical Guys Signature Series Orange Degreaser also leaves behind the pleasant smell of oranges.

Respect brand of cleaners, breaks up engine grime, removes road tar, removes grease from the garage floor, concentrated formula can be watered down for extended use on mild messes

One of the more expensive options on the list

Best on a Budget: Gunk Original Engine Bright

If you want to knock out engine gunk, there is arguably no better product than Gunk Original Engine Bright. Gunk is one of the best-known brands in the industry and the Original Engine Bright is one of its best selling products. It is specifically engineered to remove tough grease and oil build-up on older engines, particularly in the case of vehicles that have suffered from fluid leaks.

Gunk Original Engine Bright is designed to tackle the toughest engine bay mess and it does so without any scrubbing. You simply spray the Original Engine Bright on the area that you want to clean and wait 10 to 15 minutes. During that time, the Gunk spray eats into the baked-on grime, lifting it off of the various surfaces. After 15 minutes, you rinse the engine down with water and grime washes away.

Best of all, in addition to being one of the best-known brands of engine degreasers, Gunk Original Engine Bright is one of the most affordable engine degreasers available. For particularly tough jobs, Gunk offers other, high-strength engine cleaners, but for the majority of vehicles, the Original Engine Bright will get your under-hood area looking like new.

Well-known brand, inexpensive, no-touch formula rinses away

Tougher jobs may require stronger Gunk products

Griots Garage Engine Cleaner

Griots Garage Engine Cleaner is a mild degreaser that is designed for shining up reasonably well-maintained engine bays. While some engine degreasers use harsh chemicals to remove grime that has been cooked into place for years, the Griots Garage Engine Cleaner is designed for the automotive enthusiast who wants to regularly clean their engine.

If your engine bay is part of your regular vehicle detailing program, Griots Garage Engine Cleaner is the product for you. It loosens and removes dirt that collects on the engine during normal driving. If you have a hood with heat extractors or a hood scoop, you might find that the engine gets very dirty when driven in the rain. This cleaner is designed to remove that dirt without any harsh chemicals, shining up your powerplant for the next car show.

Using this product involves simply spraying it on the dirty area and taking a microfiber towel to it to help break up any stubborn solids. Once everything is loosened up, a quick rinse removes the cleaner and the dirt, while a quick wipe-down with a dry towel will prevent any water spots.

This recommendation is one of the most expensive engine degreasers on this list, but if you regularly clean your engine bay, you are likely to find it’s best for your needs.

No harsh chemicals, designed for regular engine cleaning, perfect for show car engines

Expensive, not intended for tough dirt and grime

Sonax Engine Degreaser and Cleaner

Sonax Engine Degreaser and Cleaner is designed to remove oil, grease, grime, and other debris from your vehicle’s engine. The spray bottle gets the strong cleaner into tough spots, where it then soaks into dirt that you can’t even see, helping to remove every last bit of grime around the engine bay. It is phosphate-, solvent-, and acid-free, yet it is still formulated to remove engine filth on a professional level.

Sonax Engine Degreaser and Cleaner is designed to be used on a no-touch basis, but with the grimiest engines, you may need to do a little scrubbing. You begin by spraying the areas where you want to remove engine grime and let it sit for three to five minutes. You then rinse away the dirt, oil, and debris with a strong water jet. If you find that some grime is left behind, you may need to hit the spot with a bit more of the solution, followed by a quick once-over with a scrub brush. After that, you just rinse away the mess and enjoy your nice, clean engine.

Sonax does recommend that you avoid electronic components in the engine bay and you only use the cleaner on a cool engine, out of direct sunlight. Using it on a hot engine could cause the product to dry too quickly, preventing proper cleaning and leading to spots on black plastics.

No harsh chemicals, soaks into tight spots and rinses away, designed for the dirtiest engines

One of the more expensive options

WD-40 Specialist Machine Engine Degreaser Foaming Spray

You likely know the WD-40 brand for breaking down rust and loosening bolts, but WD-40 Specialist Machine Engine Degreaser Foaming Spray is designed to break down baked-on grime on your vehicle’s engine. The aerosol can sprays up to five feet, allowing you to attack dirt in areas that you cannot reach, with the water-based foam eating into the various engine bay crud.

You simply spray this product onto the areas of your engine with tough grime. The foam sticks to those areas and expands into small spaces, breaking down the oil, grease, dirt, and grime under it. After allowing it to soak, you simply wipe away the filth. Since it is water-based, it does not damage rubber or plastic, and unlike many harsh chemical cleaners, there is no strong smell. In some cases, spraying more of the foaming spray will help to knock out any remaining debris.

In addition to using this on your vehicle’s engine, the WD-40 Specialist Machine Engine Degreaser Foaming Spray can also be used to clean tools, power equipment, farm machinery and gear-and-chain combinations. As well as the original WD-40 breaks down rust, this recommendation breaks down tough dirt and grime on all sort of engines and tools.

Insane Carburetor Cleaning Hack What You Didn’t Know

Well-known brand, available everywhere, inexpensive, water-based, no smell

Tougher jobs may require solvent-based cleaners

Engine Degreaser: Everything You Need to Know

Photo credit: Nor Gal /

lawn, mower, engine, degreaser

If you have ever been cleaning your car and you decided to clean off the engine with the same soap with which you cleaned the body, the odds are good that you weren’t very successful. Normal car wash soap and even some all-purpose cleaners won’t make a dent on the combination of dirt and oil that has been baked at extremely high temperatures for years. In most cases, normal soaps will just run off of engine grime without making any difference. To tackle that cooked-in grime, you need a designated engine degreaser.

Engine degreaser generally contains ingredients that will cut through oil-based grime, loosening the black crud that is caked like paint onto tight spots around the engine bay. Some use natural products like citrus oils, while others use solvents and other chemicals to cut through the grease and grime. In some cases, the grime is light enough that just a solid spray with a good degreasing product will remove the unwanted dirt. In the case of heavier, thicker grime, letting the degreaser soak in followed by hitting it with a brush is necessary.

There are also engine degreasers that are meant for regular use by folks who often clean and show-off their engines, but cleaning your engine bay isn’t just about looking good. Over time, excessive build-up of dirt and grime on your engine can cause mechanical issues while also making the engine harder to work on when it comes to normal, preventative maintenance.

When shopping for an engine degreaser to use on your car, you want to consider several things. First and foremost, if your vehicle is older and the engine bay has never been properly cleaned, you are going to want one of the stronger products. They are made to tackle the worst underhood filth, which is ideal for someone who only cleans their engine once in a while. For instance, if you are selling a used car and you want the engine to look great, a strong engine degreaser is a must.

On the other hand, if you have a newer vehicle with an engine that is dirty from dust and moisture of everyday driving, there are engine cleaners that are intended to remove light grime and shine up the engine for things like car shows. If you clean your engine every week, the milder cleaner should do the job for you, while also preventing the need for a harsher cleaner in the future.

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Photo credit: Nor Gal /