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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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.
- Needle-nose pliers
- Nut driver
- Socket set
- Carburetor cleaner
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- Compressed air
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BEFORE YOU BEGIN
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.
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.
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.
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Feel confident in tuning up your lawn mower or garden equipment this season with our Home Maintenance Kits. Easily find the right product so you can DIY and save!
Looking for your Serial Number?
Finding your lawn mower’s model number and serial number is as easy as locating the identification tag on your machine. As seen in the example, the model number will be displayed below the MODEL heading (Example: Z235), and the serial number will be underlined on the top-right corner of the tag (Example: 130002).
If you’re looking for the engine number, that can be found directly on the engine itself.
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The John Deere Easy Change™ 30-Second Oil Change System
Never drain engine oil again.
We’ve changed the oil change. Revolutionized it really. See how fast and easy changing your oil can now be on 100 Series Riding Lawn Tractors with the John Deere Easy Change™ 30-Second Oil Change System. Only from John Deere. Included on the E120, E130, E150, E160, E170, and E180 models.
Step One. Take it off.
Lift the hood. Make sure the engine is cool, then, twist to remove. It’s that simple.
Step Two. Twist and lock.
Grab the new Easy Change™ Canister, twist and lock into place. Make sure the arrow on your Filter System aligns with the arrow on your engine.
Step three. Done.
Close the hood and mow. John Deere recommends the Easy Change™ 30-second Oil Change System every 50 hours or at the end of your mowing season. Don’t drain engine oil ever again.
Draining engine oil is so 2017.
The engine modifications and new technologies are in. The re-envisioned oil filter with a media designed to resist breaking down in oil over time is here. The thousands of hours of testing are done. The end result is an all-in-one, oil and oil filter system like no other. The first of its kind. And thanks to the new John Deere Easy Change™ 30-Second Oil Change System (“System”), you’ll never have to drain the oil from 100 Series Riding Lawn Tractors again.
Here’s why: The new System captures contaminants and recharges your engine with nearly a quart (0.8qt) (0.76 l) of new oil. In fact, this System increases the amount of oil in the engine by nearly 40%. 2 Your engine likes that.
What do you mean, I will never have to drain oil from my engine again? How is that possible? The answer is simple. We have developed a better filtration system and filter design for our 100 Series Riding Lawn Tractors 1. This fully synthetic filter media has greater surface area which increases its capacity to hold harmful contaminants. What’s more, the filter media is designed to resist breaking down in oil over time. Which means you’ll get a cooler running engine. And a cooler running engine and better filtering helps increase engine oil life. John Deere’s recommended oil service for 100 Series Riding Lawn Tractors 1. is to change the System every 50 hours or once a season, whichever comes first. Remember, the System replaces a portion of your engine oil. And that’s plenty.
The System uses John Deere Turf-Gard™ Oil. Using John Deere Turf-Gard™ Oil ensures you are using the exact oil specified by John Deere engineers.
Testing. Testing. Testing. Thanks to thousands of hours of rigorous and extensive testing, you can feel confident your engine will run for years to come.
1 The John Deere Easy Change™ 30-Second Oil Change System is available on E120, E130, E150, E160, E170 and E180 Lawn Tractors today.
2 Compared to similar V-Twin engine models that do not have the John Deere Easy Change™ 30-Second Oil Change System. That includes equivalent Deere 2017 models and 2018 models without the System.
Frequently Asked Questions:
What is new with John Deere Riding Lawn Equipment?
We are excited about the exclusive John Deere Easy Change™ 30 second oil change system. Exclusive to John Deere and only available on certain models of the new 100 Series Lawn Tractors. These tractors are designed for ease of use for both operation and maintenance. The John Deere Easy Change™ System (“Easy Change”) allows the user to easily complete the recommended engine oil and filter maintenance in 30 seconds.
What is this new oil change system?
We changed the oil change. The all-in-one oil and oil filter system gives the owner the ability to change a portion of the oil and the filter in less than 30 seconds.
What happens to the rest of the oil in the engine when the Easy Change system is replaced?
The Easy Change system replaces.8 quart of oil. The remaining oil in the engine is refreshed by the charge of new oil included in the replacement Easy Change system. Combined with 40% more engine oil capacity, improved filtration and cooler running temperatures which help extend oil life, it is no longer necessary to remove and dispose of all the oil in your engine during service.
What makes the Easy Change system unique from other filters?
It is not just a filter. It is a newly developed technology system that allows a new “filter” to come already charged with oil and allows you to remove an existing filter and the contaminants inside without tools and without making a mess. Beyond the filter, technology within the canister and on your engine makes this possible.
Models with the Easy Change oil system use a fully synthetic filter that has more capacity to trap and hold contaminants. The larger surface area of the Easy Change canister acts like a radiator helping the oil to stay cool.
Does the Easy Change system somehow decrease the life of the engine?
The John Deere 100 Series lawn tractor models, with and without Easy Change, are specified for the same lifetime and are rigorously tested to the same standards to ensure the life of the tractor meets expectations.
Can I add the Easy change system to an existing tractor?
Because this system also requires unique features within the engine, the Easy Change system cannot be added to an engine that was not equipped with it at the factory.
Can I change all the oil if I choose to?
You could if you wanted to. There is an oil drain plug. It is not required for maintenance.
How often do I need to change the Easy Change canister?
Every 50 hours or once a year. The 100 Series Lawn Tractors with and without the Easy Change system have the same maintenance schedule.
What type of oil is recommended?
We recommend only John Deere Turf-Gard™ 10W30 Oil. The Easy Change canister comes pre-filled with John Deere Turf-Gard™ 10W30 oil.
How do I recycle the old oil?
Many local government recycling programs, authorized retailers, auto repair stations, and auto parts stores will puncture and recycle used oil filters and oil.
Do I ever need to add oil?
Yes. Consistent with our service recommendations for this product, you should check oil level daily and add oil if required.
Small Engine Carburetor Troubleshooting – A beginners guide
Small engine carburetors don’t handle bad or dirty gas very well; if you own a small engine, you’ll encounter carburetor problems at some point. In this guide, I’ll cover the main problems with small engine carburetors and the solutions.
So how do you troubleshoot a small engine carburetor? The most common issue with all small engine carburetors is gumming (old gas); cleaning the carb usually solves the problem.
Typical carburetor-related problems include:
- Tank – Outlet hole inside the tank blocks with grit stopping or slowing fuel flowing to the carburetor
- Cap – Cap allows the tank to breathe; when the cap vent fails, it seals the tank stopping fuel flow
- Lines – Leak at connection points and on occasion can block stopping fuel flow
- Tap – Leak, causing fire risk
- Fuel filter – Block or slow fuel flow to the engine
- Pump – Fail causing a no start (Not fitted to all mowers)
- Carburetor – Block, under fuel and over fuel causing no start or poor running
- Fuel solenoid – Fail, stopping fuel flow (Not fitted to all mowers)
- Intake manifold – Leak, causing engine surging
- Dirty refueling can – Often the source of the dirt
- Air filter – Can block, causing no start or poor running with black smoke
This guide will help you diagnose and fix your fault quickly. Although this guide covers a tractor mower carburetor repair, it will work for all small engine four-stroke engines, as they all run very similar gas systems. There are many components in the fuel system that can cause issues but by far, the most common fault – Carburetor contamination.
Very often, 5 minutes spent simply draining the gas bowl fix carburetor problems. It’s all covered here in this post, or you can check out the “Carburetor bowl draining video” and also the “Carburetor cleaning video.”
The videos walk you through the whole process – removing, stripping, cleaning, reassembly, and refitting. A good cleaning and fresh gas fix most carburetor issues.
What Is Gumming?
Basically, it’s old stale gas that turns to a sticky gel; it clogs up the tiny passages of the finely balanced carburetor. Cleaning usually solves the problem, but if it’s bad, don’t waste your time cleaning, go ahead and change out the carburetor.
How Does it Happen?
Ethanol fuel is blended with regular gas, that’s not a problem for cars, but it is for small engines. Typically, the small engine is put away for winter with the gas still in the tank. The ethanol blend attracts moisture, and the alcohol content in the gas evaporates. The result is gumming and rust – it’s a carb killer.
To prevent this from happening, I use a gas stabilizer at the end of the season, mixed with the gas; it’ll keep it fresh for up to 2 years, so next spring it’s pull and mow. I use a product called Sta-bil gas treatment, 1 ounce treats up to 2.5 gallons; it prevents gumming and cleans the fuel system.
It can be used in all gas-powered kit including 2-stroke engines. You can use it all season; I only use it at the end of the season and when winterizing. You’ll find a link to the gas stabilizer I use here on the “Small engine repair tools” page.
Of course, not all fueling system faults are gummed-up carburetors – running some simple tests will point you in the right direction.
Gumming – Gas turns to a gel and blocks everything up – ya nasty. When it’s bad, I prefer to replace the carb. Cleaning doesn’t guarantee that you get it all, then you’re tearing it down again.
Replace – Don’t even think about it. Order a new one!
Symptoms Of Carburetor Faults
How my customers describe fuel system faults, one or more of these may sound familiar.
Customer complaints include:
- Mower stops for no reason
- I put the mower away for winter, and now it won’t start
- Engine runs rough
- Engine splutters when I cut on a slope
- Engine dies when I start cutting grass
- Black smoke from the muffler
- Engine revs up and down by itself Mower only runs on choke
- Mower blows white smoke
If any of these sound familiar, you are in the right place.
Carburetor Fault Finding
At this point, it’s assumed that you have run the Gas Shot Test and Choke System Check, and they both confirmed a fueling fault. If that is the case, your symptom will fit one of the following descriptions:
Mower won’t start; Runs rough; Blowing black smoke; Starts then dies; Surging; Lacks power; Only runs with choke; Gas leaking into the oil; Blowing white smoke; engine revving up and down by itself; Mower only runs on choke”; Mower blows white smoke.
OEM – Carburetors aren’t expensive or difficult to fit. Sometimes it’s better to just go ahead and replace the whole unit. Carburetors do wear out, and I replace lots of them.
honda model hrr216k9vkaa lawn mower carburetor repair
A fuel solenoid is an electromagnetic valve that simply opens as you turn on and run the mower engine. When the valve is in the open position, it allows gas into the engine.
The purpose of the valve is to close at shutdown and prevent gas leaking into the engine, which helps prevent engine run-on.
Not all mowers will have one fitted, but if you have, it will be easy to spot. It lives on the bottom of the carburetor bowl and has an electrical wire and connector fitted.
To test the solenoid, turn the ignition on (without starting the motor), locate the sensor, and disconnect the wire; now, reconnect and listen for the click sound. If you don’t hear a click, you could have a solenoid failure or a power supply problem.
Removing the solenoid is the best way to test; that allows you to see it actually open and close. If you have a power supply problem, use a DVOM or test light to check for power.
If the solenoid fails, the mower won’t start, and a failing solenoid will cause problems like, only working when it wants to, or shutting down the mower. Changing out the solenoid is easy.
Test – Remove the connector to test for the click sound, or use a test light to check for power. Briggs and Kohler’s solenoids are shown here.
Fuel Bowl Clean
In some cases, you may only need to drain the fuel bowl. In other cases, you will need to remove the carburetor and clean it thoroughly. Your carburetor may look different, but the process is the same.
In this part of the guide, I will drain just the fuel bowl and check the fuel flow. You can find your fuel bowl behind the air filter. You don’t need to remove the air filter housing to access the bowl.
Remember, if your ethanol gas is much older than one month, it’s stale. Cleaning the bowl won’t make it go. You need to drain the tank, and carburetor bowl and fill them with fresh gas.
I use the Briggs and Stratton oil extractor to remove stale gas and grit from the bottom of the gas tank; it’s easier than removing the tank. Check out the one I use here on the “Small engine repair tools” page.
If this works out, great! If not, I wrote this guide, which will walk you through the whole process –“Remove Clean Carburetor”.
Alternatively, it’s all covered in this video, from bowl drain and cleaning, complete carburetor removal, stripping, cleaning, rebuilding, and refitting. It’s all covered here “Carburetor cleaning video”.
Carburetor Bowl Draining
Locate – The carburetor is located behind the air filter, and you usually have enough room to work without removing any other components. Turn the gas off; if you don’t have a tap, use grips to squeeze the line.
Remove – This type of bowl doesn’t have a solenoid. Remove this bowl by removing the bowl bolt. An O-ring gasket is used to seal the bowl to the carburetor. Usually, it stays on the carburetor side, and that’s OK; you can leave it there. Clean the bowl, and when refitting, uses some lube on the o ring seal to prevent pinching.
Remove – This carburetor has a fuel solenoid. To remove it, disconnect the wire connector and use an open-ended wrench between the bowl and the solenoid.
Sometimes you can just turn the bowl by hand. Remember to lube the gasket when refitting the bowl. Often no matter how careful you are, the bowl gasket will leak gas; if so, the only fix is to replace it.
Remove – Remove the fuel bowl drain bolt, which on some models is also the fuel solenoid. Your bowl may have a bolt or two screws, and in some cases, the whole bowl will come off. Allow the fuel in the carburetor to drain out, catch it in a suitable container, and have some old rags handy. If you have any doubts about fuel quality, drain the tank and fill it with fresh gas.
Testing Fuel Flow
Flow – The carburetor bowl type with two screws can be tricky to remove, so if that’s your type, just remove the solenoid, allowing the gas to drain, reassemble and test. Often this is enough to fix the problem. But before you reassemble, check the fuel flow on whichever type of bowl you have. Turn the fuel on. If fuel flows – Refit the fuel bowl bolt and test the mower. If there is no fuel flow, we’ll need to dig a little deeper.
If you removed the fuel bowl or drain bolt and found no fuel flowing, or the carburetor needle is leaking gas even with the float in the shut-off position (Up), then this guide will help you. This guide works just the same for walk-behind mowers, lawn tractors, ride-on mowers, tillers, snow blowers, or any 4-stroke small engine.
Riding lawn mower fuel systems are either gravity feed or pump feed; your mower will be one or the other. You will be able to identify which system you have by following the fuel line from the fuel tank. Go ahead and identify your system, and carry out the checks as directed.
A weak carburetor float needle is a common problem, it causes gas to flood the engine oil, it’s known as Hydro-locking, and we’ll deal with it first before looking at identifying your fuel supply system.
Gas leaks into the cylinder, when the mowers are not in use, filling it right up. This prevents the engine from cranking over because the piston has no room to move. Some owners think that the battery is flat, and try jump-starting without success.
Other tell-tale signs of hydro-locking are a stink of gas in the garage, gas on the floor of the garage, mysterious loss of gas from the tank, and a very high oil level that stinks of gas.
CLEANING A Briggs & Stratton Quantum Lawnmower Carburetor
Some mowers may start when most of the gas leaks from the cylinder into the oil. The operator then notices lots of white smoke, rough running, stalling, and oil leaks.
The fix – replace the whole carburetor, because often just replacing the needle seal doesn’t work. Fitting a gas tap, and turning off the tap when the mowers are not in use will prevent future problems. But it’s important to change the engine oil; it’s diluted and contaminated by the gas.
This guide will show you how to fit a tap and the tools needed – “Fitting a gas tap.”
Identifying your fuel supply system
Gravity Fuel System – Identified by a fuel line from the tank runs to a fuel tap, through a fuel filter, and onto the carburetor. (Tap may not be fitted) This system is prone to leaking gas into the oil and causing a condition known as hydro-locking.
Pump Fuel System – A fuel line from the tank runs to a fuel tap, then a fuel filter, then a fuel pump, and finally to the carburetor (Tap may not be fitted).
Fuel Supply Troubleshooting
Remove Gas Cap – A gas tank needs to breathe; when fuel leaves the tank, it needs to be replaced with air. A sealed tank will prevent fuel from flowing. Make sure you have gas in the tank. Remove the gas cap and check the flow. Check the fuel tank for grit – the outlet hole is small and blocks easily. You may have to remove the tank to clean it thoroughly.
Filter – Examine the fuel lines from the tank to the carburetor, checking for kinks or damage. Some fuel filters will be a see-through bottle type; if it’s dirty – Change it. Arrow to carb.
Remove – Remove the gas bowl – when the float is in the dropped position, the gas should flow.
Needle – Remove the float and needle, and check the condition. A worn needle turns pink in color. The needle seals the flow of gas when the float is in the up position. A worn needle can block the flow or cause gas to leak into the oil. When this happens, I prefer to replace the complete carburetor.
Spray – Blow some carb cleaner into the needle seat on the carburetor. Still, no flow – Remove clean the carburetor; consider replacing the complete unit. Some carburetors have the seal on the tip of the needle, and others have the seal in the carburetor. Carb was removed for the demo.
Gas Pump – The pumped system is, as said, very similar. Check that the gas filter supply to the pump is OK. The fuel pump operates by the pulsing of crankcase pressure which is supplied by the hose pipe seen in the center of the picture. Check this pipe is secure and undamaged; sometimes, they perish.
To test the pump – Remove the output line on the left and crank over the engine. No fuel flow – Replace pump.
Remove Clean Carburetor
Okay, I will assume you have tried cleaning the bowl as per the above guide without success. Now you need to remove the carburetor and clean it.
Only basic tools are needed, but a can of carburetor cleaner makes life a whole lot easier. In the workshop, I use WD40 cleaner; check it out on “Small engine repair tools” page. A container for nuts and bolts, some rags, and take lots of pictures to help you remember where levers, gaskets, and springs go.
Your carburetor may not be the same as the one used here, but yours will look very similar, and the process is the same.
The whole process is covered in the “Mower surging video” and if you need to replace the carburetor, check out the Amazon carburetor link below.
Remove – Remove the air filter and engine plastic cover.
Remove – Remove the choke cable.
Turn off the gas and remove the fuel line. If you don’t have a gas tap, use grips to gently squeeze the line.
Remove – Remove the intake pipe.
Remove – Unplug the solenoid valve and remove both carburetor bolts.
Remove carburetor fasteners
Photo – Take note of linkage, spring and gasket locations, and orientation before removing.
Remove – Remove the float by sliding the pinout and removing the needle. When worn, the needle seal turns pink. Carburetor kits will include new bowl gaskets and needle seals.
Remove – When removing the fuel/air mix screw, count how many turns it takes to remove it and refit to the same number.
Remove – Remove the main jet with a flat screwdriver. Jets are made from brass which is a soft metal and will damage easily. Be sure the screwdriver is a good fit.
Remove – The dirt collects in the emulsion tube; it houses small portholes through which fuel flows.
Clean – Clean the jet and emulsion tube really well, the portholes may not look dirty, but a build-up around them makes them smaller and restricts gas flow. Use a strand of wire from a wire brush and run it through the holes.
Check – The bowl gasket may be distorted or perished. Over-tightening or pinching will cause it to leak. To avoid damage, lube o ring on reassembly.
Spray – Use a good quality carb cleaner and compressed air if available. Spray all passages and portholes.
OEM – A new carburetor makes a bit of difference; cleaning won’t guarantee it runs sweet. So, if cleaning doesn’t work out, go ahead and treat your mower to a new carb.
Finally – When rebuilding, replace the gas filter. Clean your gas can and fill it with fresh gas. If you’re storing the mower for periods longer than a month, use a gas stabilizer. It will prevent gumming.
What can a dirty carburetor cause? A dirty carburetor can have many symptoms; here’s the most common:
Why is my carburetor not getting gas? The most common reason a carburetor isn’t getting gas is because of a Dirty carburetor gas bowl, but there are other possible reasons:
Hey, I’m John, and I’m a Red Seal Qualified Service Technician with over twenty-five years experience.
I’ve worked on all types of mechanical equipment, from cars to grass machinery, and this site is where I share fluff-free hacks, tips, and insider know-how.
And the best part. it’s free!
Where is the Carburetor on a Lawn Mower? (every mower)
Do you need to do some troubleshooting or maintenance with your lawn mower? If so, you’ve probably wondered where the carburetor is on a lawn mower. The location of this component of your mower’s engine can vary depending on the type of lawnmower you have.
In today’s article, I’ll tell you what a lawn mower carburetor looks like, where it usually is found on every type of mower, and provide a list of cleaning tips to maintain your mower’s carb.
All About the Lawn Mower Carburetor
What it Looks Like, What Parts of the Mower it Connects to, and
The carburetor is an essential part of your lawn mower’s engine. It makes sure that the correct combination of fuel and air will go into the engine cylinder. This is essential for combustion to occur.
When the spark plug ignites the fuel and air mixture, it combusts and pushes the engine piston in a downward direction. This, in turn, rotates the crankshaft. This makes the lawn mower blade spin.
Depending on the type of lawn mower you have, the wheels of your mower (for example, a riding mower or self-propelled mower) will also start to rotate.
How to Find and Identify Your Mower’s Carburetor
The carburetor is part of the mower’s engine. Typically, it is bolted to the side or top of the engine. It is also connected to the gas tank, and will typically be located just below or behind your air filter. Most lawn mower manufacturers make the air filter housing easily accessible and easy to identify so that owners can change out the filter as part of their annual maintenance. Find the air filter and your mower’s carburetor will be the next part of your mower’s engine, right behind it.
While the location will vary by manufacturer, there are a few qualities most carbs share to make them easier to identify.
Carburetors are metal and rectangular in shape. Your mower’s carb will often have black areas, such as a black circle and trim on the right and left.
In this article I’ll walk you step-by-step through locating and servicing your mower’s carburetor, with specific tips for locating the carburetor on every type of lawn mower.
Different Kinds of Lawnmower
In this section, we will go over the different kinds of lawnmower and where you can usually find the carburetor in each. The two main kinds of lawnmower are walk-behind and riding.
There are four main types of walk-behind mowers, which I list below – if you own a walk-behind mower make sure you know which type it is so that you can refer to the correct part of this article to locate your mower’s carburetor:
- Electric walk mower: An electric walk mower is appropriate for smaller properties.
- Self-propelled mower: A self-propelled mower is handy because it propels itself, meaning it’s a lot less work when mowing hilly areas. If you get a self-propelled mower, you can choose front-wheel drive or rear-wheel drive. Front-wheel drive is suitable for level ground. A self-propelled mower with rear-wheel drive is most suitable for sidehill and uphill mowing.
- Two-function mower: A two-function mower mulches and bags as well as does the usual grass cutting.
- Three-function mower: A three-function mower cuts the grass as well as bags, mulches, and side discharges.
There are three main types of riding lawn mowers, which I list below. If you own a riding mower, make sure you know which type it is so that you can refer to the correct part of this article to locate your riding mower’s carburetor:
- Rear Engine Riding Mower: The rear engine riding mower is the smallest of riding mowers.
- Lawn Tractor: Lawn tractors (sometimes called garden tractors) have very powerful engines, which are great for large properties.
- Zero Turn Radius Mower: Zero turn radius mowers are also very powerful, but they are easier to maneuver.
Carburetor Location in Walk-Behind Mowers
For walk-behind mowers, you will find the carburetor at the side of the mower, in the area above the base of the mower. As we mention later, the carburetor is connected to the air intake and air filter of the mower. Therefore, finding these components makes it easy to find the carburetor.
If you’re having trouble finding them, search for square-shaped or round-shaped filter housing. This will generally be on the side of the mower’s engine, though it’s sometimes on the top.
The air filter case is usually plastic and pops open easily to provide easy access to the filter for maintenance. The mower’s carburetor is just behind the air filter’s housing, and there are typically 2-3 bolts that can be loosened to remove the filter housing and reveal the carb.
This video does a nice job demonstrating the removal and cleaning of the carburetor on a walk-behind mower:
The exact process for repairing or replacing a carburetor in a riding mower will depend on your exact model, and it tends to be more complicated than working with the carburetor of a walk-behind mower, so you may choose to hire a professional at a small engine repair shop to do this for you.
If you are going to do a carb repair or replacement yourself, my advice is to consult the manual that came with your machine, and document every step of the process so that you can remember how the carb was set up and have an easier time re-attaching everything properly.
Here’s a video from Sears that walks you through replacing the carburetor on a Craftsman Mower. It provides a good sense of what’s involved in this project, what your riding mower’s carburetor looks like, and where the carb is located on some riding mowers:
- Step 1: Turn off your mower’s ignition and use the parking brake. To stop any accidental rolling, put the mower in gear.
- Step 2: Make the mower’s engine accessible by releasing any restraining devices (such as hood latches) that are holding down the hood.
- Step 3: Find the air intake and the filter. You should find filter housing (square or round-shaped) on the side or top of the engine. This will have slits or holes in the top. The filter housing will be attached to the carburetor by screws or latches. This housing contains a filter made of foam or paper. The filter found within the housing is there to stop dust and dirt from getting into your mower’s carburetor.
- Step 4: Locate the fuel line that comes from the gas tank. You can use this information to find where the gas tank. Gas tanks will usually be mounted in a place that makes it easy to access for re-fueling and is often black.
- Step 5: Find the fuel line that comes from the tank. This line will usually be situated in close proximity to the bottom of the tank. A small clamp is usually there to attach it. You can trace the fuel line that attaches the tank to where it connects with the carburetor.
Why is it Important to Clean Your Lawn Mower’s Carburetor?
The carburetor of your lawn mower needs to be kept clean in order for the machine to work as it should.
Think of the carburetor in a car. If it isn’t kept clean and properly maintained, your vehicle will not run properly.
This is the same with a small engine such the kind you have in a lawn mower.
If you are having certain problems with your mower, there is a good chance that you need to clean the carburetor. Below are some signs of a dirty carburetor:
- You’re having problems with the engine stalling when you are trying to cut the lawn.
- You are having difficulty starting the mower.
- There is black smoke coming from the muffler.
- The engine is sputtering or running turbulently during mowing.
- You have noticed an increase in your mower’s fuel consumption, even though you are using the way you always have.
How to Clean a Mower Carburetor Once You Locate It
Let’s take a look at how to clean a lawn mower carburetor.
Please note that these are general instructions and you should consult with the instructions that come with your particular mower before you proceed.
Removing the Carburetor
- You must completely remove the carburetor from the lawn mower before trying to clean it.
- If it is necessary, take off the engine cover.
- Take off the cover of the air filter, the filter, and the housing of the air filter.
- If possible, turn off the fuel valve. If this isn’t applicable, make a crimp in the fuel line. After that, take it off the carburetor. Be ready for a bit of fuel to spill out. You can use a rag to deal with the mess.
- Get the choke and throttle linkages detached from the carburetor throttle lever.
- Use a sliding motion to remove the carburetor from the mounting bolts.
- If necessary, release the carburetor bowl by unthreading the screw. This will release the bowl.
- Release the float and needle by removing the float pin.
Cleaning the Carburetor
- To completely take apart the carburetor, you will possibly have to unthread screws so that the primer bulb and base are released. After that, take out the metering plate, diaphragms, and gaskets.
- The outlet ports and carburetor intake should be exposed. You should then use a special carburetor cleaner spray (if you don’t have that, then WD-40) to clean out residue from the ports.
- If there is a bowl, clean it out.
- Check if there are any signs of rust in the carburetor. If so, get rid of it with sandpaper.
- Give the carburetor time to dry. After that, put it back together. Ensure that the diaphragms, metering plate, gaskets, and primer base are correctly positioned. Also do the same with the float and float needle.
- Ensure that you put the bowl gasket back in its correct place. Reinstall it if that is necessary.
- Use a sliding motion to reinstall the carburetor onto the mounting bolts. Get the throttle linkages re-attached to the throttle lever.
- Reattach the carburetor to fuel line.
- Reinstall the air filter, filter cover, and air filter housing.
- If this is necessary, reinstall the engine cover.
What if the Carburetor Needs Repairs?
It is possible that your carburetor will need repair as well as cleaning. If that is the case, you can consider buying a carburetor repair kit. This will help you with replacing some of the major components of the carburetor, such as the diaphragms, gaskets, float, and float needles. You can probably find a kit that matches your mower on Amazon for less than 20.
If you find that the carburetor continues to have poor performance, it’s possible that you will have to get a new carburetor and replace the old one. The price of a replacement carburetor will typically be about 50, and you can find genuine manufacturer’s carb replacements on Amazon (like this one for a Honda self-propelled mower).
If you’re sure your lawn mower issues are the result of carburetor problems, it’s generally easier to buy a new carb and replacing the whole thing vs attempting to repair a few gaskets or parts.
In my experience a repair kit works better in theory than in practice, and your average weekend warrior is better off replacing the whole thing if determined to DIY a fix. For 30 more, why not install a brand new carb?
The other option (recommended for most people) is to take your mower to a small engine repair shop and let them do the work for you. This is less expensive than you’d think, and will save you some time and headaches.
For optimal lawn mower maintenance, you should clean the carburetor every year.
This will help your mower always perform at the optimal level and help to hold off problems that will require parts replacement or full replacement of the carburetor.
And you don’t have to take your carb out to keep it running like new – I give my mower a shot of Gumout Carb and Choke Cleaner (Amazon link) before every mow to keep it running like new. It’s like 5 a can and lasts a whole season.
Maintain Your Lawn Mower So It Lasts!
Understanding how your lawn mower works and how to maintain it is key to making it last.
Purchasing a new lawn mower is an investment, so it’s well worth taking the time to read the manual and understand all the components and their functions.