Riding mower carburetor adjustment. Here’s What To Do If Your Lawn Mower Won’t Start

Learn the reasons why a lawn mower won’t start after winter or during peak season, and how to fix those problems.

Family Handyman


Most of the time when a lawn mower won’t start the cause is a problem with the gas or the lawn mower carburetor.

What to Do if Your Lawn Mower Won’t Start

Whatever kind of lawn mower you’ve got, the last thing you want once winter finally lifts and spring has sprung is a lawn mower that won’t start.

If you’ve taken the proper steps to winterize your lawn mower, you’re far less likely to be dealing with such issues. It’s also why you should tune up your lawn mower at the start of every season. However, it’s not out of the ordinary to find your gas-powered lawn mower not starting from time to time, so it’s important to know why your lawn mower isn’t starting and how to fix it.

Project step-by-step (6)

Check the Gas Tank

Let’s start with the obvious. Before you have a heart attack pulling on the rip cord, you’ll want to check the fuel. Like any gasoline-powered engine, lawn mowers run out from time to time. Maybe you forgot it was running on fumes when you finished mowing last time. It sounds simple, but we’ve all overlooked the gas tank from time to time.

Even if there is gas in the mower, if the fuel’s been in there more than a month, that could be the problem. Gas sitting around too long in the tank can get contaminated with dirt and extra moisture.

So if your gasoline has been in the mower for more than month, drain the gas properly, dispose of it correctly, and fill up the mower with new gas. It may take quite a few pulls to suck the new gas into the lawn mower carburetor, so be prepared to clean and dry the plug a few more times.

Add fuel stabilizer when you fill up the tank to help protect the gasoline in there from dirt and moisture.

Family Handyman

Check the Spark Plug

Start by making sure the lawn mower spark plug cable is connected to the plug itself. It’s quite possible that it got pulled off there over the winter while the mower was being stored in the garage.

If that’s not the issue, the next step is to remove the spark plug to see if it’s wet. There’s no way the engine will start if it is. So clean the plug with carburetor cleaner and let it dry. Cleaning it with compressed air isn’t enough; you need a solvent to remove oil residue. If it’s really grimy and dirty, it might be best to change the spark plug.

Fertnig/Getty Images

Check for Debris in the Mower Deck

Grass clippings can get clogged in the mower deck, which can prevent the blade from turning. This is a common problem if you’ve cut wet grass or let the lawn get especially long and bushy between cuttings. If the cord is hard to pull, that’s a good sign that there’s debris clogging up your mower’s deck.

This is a pretty easy problem to solve. With the mower off, flip it on its side or upside down and scrape out the gummed up grass clippings. Once that’s done, you can flip it back over and start it up again.

JJ Gouin/Getty Images

Check the Air Filter

The lawn mower’s carburetor regulates the mix of gasoline and air going into the engine where it’s burned to create power. Before air goes into the carburetor it passes through the air filter which prevents dirt and debris from getting into it.

If the air filer is clogged or dirty, it throws the ratio out of whack. Sometimes that results in your lawn mower smoking, and sometimes it prevents it from starting entirely. So take a look at the air filter to see if it’s dirty. If so, you can clean it or just change it outright.

Robert Maxwell for Family Handyman

Check the Carburetor

Another common reason for a lawn mower that won’t start is a clogged or dirty carburetor. It can also cause your mower to run rough or spew black smoke when you’re trying to cut the grass. If that’s the case, you may need to clean the carburetor.

To get to the carburetor, you’ll have to remove the air filter. Once that’s out of the way, you can remove the carburetor in order to clean it.

Once it’s out, check for corrosion. If you see chalky/powdery white corrosion like this, it’s probably better just to replace it. To clean it, take it apart and spray carburetor cleaner on the parts and inside the housing. After that, put the carburetor back together and reinstall it in the mower.

Check the Fuel Filter

Like the air filter, the fuel filter prevents dirt and debris from getting into the combustion chamber of your lawn mower’s engine, taking that stuff out before the gas gets mixed with air in the carburetor. Problems with the fuel filter might also result in the engine sputtering or rough idling, even before it gets to the point of preventing the mower from starting.

To start, tap the side of the carburetor to help the flow of gas. If that doesn’t work, you might have a clogged filter.

Not all lawn mowers have a fuel filter, but for the ones that do, it’s usually located in the fuel line or the fuel tank. To find out where the fuel filter is at, check your lawn mower’s owners manual, which will also tell you what type of filter it is.

If the filter is in the fuel tank, you’ll need to drain the gas from the mower into a drain pan, assuming you can’t run the engine until it’s out of gas. If the filter is in the fuel line, clamp off the fuel line before removing the filter. Once you have the filter off, you can check to see if it’s dirty and clogged by holding it up the light. If it is, install a new one. Make sure it works with this lawn mower maintenance checklist.

How to Adjust the Carburetor on a Lawn Boy

A dead give-away that you need to adjust the carburetor on your Lawn-Boy mower is excessive gas consumption or black smoke when the mower is in operation. If your Lawn-Boy has been in storage for a while or was recently serviced, it may need a carburetor adjustment. The process is the same for any model of Lawn-Boy.

You just need to know where to locate the adjustment screws and how to adjust them to keep your Lawn-Boy mower running smoothly.

  • Locate the carburetor on your Lawn-Boy mower. Start at your gas tank, find the fuel line and follow it to the carburetor. If your model is equipped with a fuel pump, continue following the line from the fuel pump to the carburetor. The fuel pump looks like a tube, but the carburetor looks like a tube with a flat box on top with a circular attachment on the side.
  • Identify the three adjustment screws. If you can see two screws next to each other on the outside of the carburetor, the screw closer to the engine block is the idle air mixture screw. The one farthest from the block is the main air mixture screw. If you only see one screw on the side, that is the idle screw. The main air screw will then be located toward the bottom of the carburetor. The third adjustment screw will be located either to the front or rear of your carburetor, depending on your model. This is the screw used to set your engine idle.


Not turning the screws far enough is the most common mistake people make in adjusting a carburetor. Use a screwdriver with the name molded into the handle or place a mark on the handle so you have a point of reference. Insert the head of the screwdriver into the screw, making sure the mark or label on the handle is facing up. Turn the screwdriver until the label returns to the upright position to make one complete turn. A half turn will put the label or mark facing down.


Set the brakes on the wheels of your mower before adjusting the carburetor, and use a helper whenever possible. When you give the mower gas and are still making adjustments, you do not want the mower to move or it could cause serious injury.

The Drip Cap

Cassandra Tribe has worked in the construction field for over 17 years and has experience in a variety of mechanical, scientific, automotive and mathematical forms. She has been writing and editing for over 10 years. Her areas of interest include culture and society, automotive, computers, business, the Internet, science and structural engineering and implementation.

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

We may earn revenue from the products available on this page and participate in affiliate programs.

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.

Lawn Mower Repair : Troubleshooting Carburetor Problems in a Riding Lawn Mower

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

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.


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.

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.

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.

riding, mower, carburetor, adjustment, here

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.

Fuel Solenoid

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.

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.

This “QUICK FIX” will destroy your mower! DON’T FALL FOR IT or it will cost you BIG later!

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.

riding, mower, carburetor, adjustment, here

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.

Related Questions

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!