Mower not getting gas. Common Engine Issues and Solutions for Lawn Mowers

Troubleshooting Lawn Mower Starting Problems

The air is warmer and the grass is growing – time to break out the lawn mower. Unlike your car, your lawn mower and other lawn and garden equipment are not used regularly and the time spent sitting in storage can lead to problems with them running properly.

When you take your mower out for the first time, you may encounter a variety of situations. If you are lucky, the lawn mower will start with the first pull of the cord. Unfortunately, after months of sitting around, it is likely your lawn mower may not run smoothly, or even start at all. Before you give up, here are some things you can do to troubleshoot the problem.

Causes of engine trouble

If your engine starts but does not run smoothly or doesn’t start, the culprit could be air intake or fuel system related. The problem could be the age of the fuel in the tank, dirt or debris in the carburetor or an obstructed fuel tank vent. Other causes could be a fouled spark plug or a dirty or clogged fuel filter that restricts the amount of fuel getting to the carburetor.

Change the gasoline

If this is the first time you have tried to start the engine since last fall, fresh fuel may be in order. Gasoline will go bad in as few as 30 days, especially when fuel is mixed with ethanol as it is in many areas. Ethanol attracts moisture and over time the moisture will dilute the gas.

If the fuel is old, it should be dumped into a container for proper disposal and fresh fuel should be added. Fuel additives are readily available wherever auto parts are sold and may be helpful in not only starting your engine, but also in cleaning out any gum or varnish deposits in your carburetor while the engine is running.

After adding new fuel, check the gas cap. In many small engines, the gas cap also has a vent that serves as the fuel tank ventilation. In order to work properly and supply a sufficient amount of fuel to the carburetor, the vent must be open and free of any debris.

Check the air filter

The job of the air filter is to remove dirt and debris from the air before it enters your engine. The filter may become clogged and not allow a sufficient amount of air into the engine for it to run smoothly. If the filter is dirty, it should be replaced.

Examine the spark plug

A dirty or fouled spark plug can cause your lawn mower to not start. It can also work itself loose, causing issues. If the spark plug appears to be seated correctly but the engine doesn’t start, a new one may be in order. For a few dollars, this easy fix can get your small engine working again. Be sure to use the correct replacement spark plug designed for your lawn mower.

Check the oil

Check the amount, color and consistency of the oil. If it appears dark black, change it. If the oil level is low, add the proper oil, identified by your owner’s manual, to the engine – but be careful not to overfill it!

Look at the Fuel Filter

The fuel filter keeps dirt and contaminants in the fuel from getting into the carburetor. If it becomes clogged, it can prevent a sufficient amount of fuel from passing into the combustion chamber, preventing your engine from starting. Check the fuel filter, replace it if it is dirty or clogged.

I’m still having issues with my mower – what should I do?

If you are still having problems, it might be time to take it to a small engine repair shop to have a mechanic look at it. With their expertise, they’ll get to the bottom of the problem in no time.

Learn more about Champion parts, find your car part, or find where to buy your auto part today.

The content contained in this article is for entertainment and informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. We encourage you to consult with a certified technician or mechanic if you have specific questions or concerns relating to any of the topics covered herein. Under no circumstances will we be liable for any loss or damage caused by your reliance on any content.

Common Engine Issues and Solutions for Lawn Mowers

A reliable lawn mower is essential to maintain a healthy, well-groomed lawn. However, like any mechanical device, lawn mowers can experience some issues that may hinder their performance. Continue reading to learn more about some of the most common lawn mower problems and practical solutions to fix or prevent them.

Why is my lawn mower smoking?

If you notice smoke coming from your lawn mower, it is typically a sign of an underlying issue. One common cause is an oil leak. Check the oil level and review the mower for any visible leaks.

If you find a leak, replace the damaged gasket or seal and ensure the oil is filled to the appropriate level. Smoking can also occur from an overfilled oil reservoir. If so, drain the excess oil and refill to the recommended level. A dirty or clogged air filter can also cause smoking. Remove the filter, clean or replace it if necessary, and ensure proper airflow to the engine.

Why did my lawn mower lose speed while running?

Losing speed while operating your lawn mower can be frustrating. One possible cause is a clogged or dirty air filter. Restricted airflow to the engine can result in decreased performance. Clean or replace the air filter regularly for optimal air intake.

If it is not an airflow problem, another cause could be a worn-out or loose drive belt. Inspect the drive belt for wear, such as cracks or fraying, and replace it, if necessary, as well as check the tension of the drive belt and adjust it as per the manufacturer’s guidelines.

A dirty or malfunctioning carburetor can also cause speed issues. Clean or repair the carburetor to restore proper fuel flow and maintain a consistent speed.

Why did my lawn mower lose power while mowing?

Losing power while mowing can be caused by a few different things. One common cause is a dirty or clogged fuel system. Debris and sediment can accumulate in the fuel tank, fuel lines, or carburetor, obstructing fuel flow over time. Clean the fuel system thoroughly, replace the fuel filter if necessary, and use fresh fuel.

A worn-out spark plug may also cause your lawn mower to lose power. Remove the spark plug and examine it for signs of fouling or damage. Clean or replace the spark plug as needed to ensure proper ignition.

Finally, check the mower’s blade for dullness or damage. Sharpen or replace the blade to maintain efficient cutting performance.

Why is my lawn mower making unusual noises?

Unusual noises coming from your lawn mower can indicate an underlying problem. A common culprit is a loose or damaged blade. Turn off the mower, disconnect the spark plug, and inspect the blades for looseness or damage. Tighten any loose bolts or replace the blade if necessary.

Another reason for unusual noises could be a faulty or worn-out engine component. Check the muffler, spark arrestor, or other engine parts for signs of damage or malfunction. Tighten any loose connections or replace damaged components as needed.

Additionally, inspect the mower for any foreign objects lodged in the cutting deck or other moving parts, as they can cause strange noises.

How can I prevent some of these common problems?

Routine service and maintenance are key to avoiding common lawn mower problems. A few tips to consider are:

• Regularly check and clean the air filter to ensure proper airflow.
• Keep the cutting deck clear of debris to prevent any impact to performance or unusual noises.
• Follow the manual recommendations for oil changes and use the correct type and grade of oil.
• Inspect and sharpen blades regularly for clean and efficient cuts.
• Replace the spark plugs according to manual recommendations.
• Clean the fuel system and use fresh fuel to prevent clogs and fuel-related issues.
• Store the mower in a clean, dry area, out of the weather elements.
• Use proper John Deere parts for your equipment.

Where can I find lawn mower service near me?

Addressing common lawn mower issues promptly helps keep your mower in top shape to provide you with a well-maintained lawn. Whether it is troubleshooting smoking problems, loss of speed or power, unusual noises, or implementing preventative measures, the certified technicians at your local Koenig Equipment are here for all your lawn mower repair needs, regardless of the brand.

Contact your local Koenig Equipment or schedule service online at any time.

Here’s Why Your Lawn Mower Won’t Start And What To Do About It

Standing in your garage with a dead lawn mower, a phone browser open to Google, and the vast untamed landscape of small engine troubleshooting before you, it can be easy to get discouraged. After all, just about anything that prevents a lawn mower from running well can also prevent it from starting. Let’s simplify all these possibilities and zero in on common starting problems, and ones that you’re likely encountering.

Of course, your situation could include all manner of devices thought of as mowers. You could have a simple push mower, or maybe an electric start push mower. But, you could also have a riding mower, an electric mower, or a zero-turn mower that costs more than a Chevrolet Spark. You might even have a tractor towing a rotary cutter like a Bush Hog, in which case you’re probably not reading this article. We’re going to take a look at the most common: push mowers and riding mowers. Your electric mower is essentially always started, and your licensing agreement might prohibit your working on your own tractor. We also won’t deal with zero-turn mowers directly, but obviously a lot of the info for small engines in general will apply to zero-turns. Let’s dive into some of the reasons your mower may not be starting, and what you should do about it.

Ignition system problems: spark plugs

At some point — possibly when the words we have ignition from the Kennedy Space Center Firing Room — many of us began to think of the word ignition as synonymous with starting, but that’s not exactly what’s going on with ignition systems. An ignition system is actually about producing a spark that ignites a fuel-air mixture within an engine’s cylinder(s). Ignition happens continually when you’re using a mower. A few components of this system can be culprits when an engine won’t start.

The most common culprit is probably a spark plug that needs cleaning or replacement. Buildup from a constantly exploding engine cylinder will eventually degrade the performance of the plug until it can’t function properly at all. It’s a little easier to diagnose a bad spark plug in an engine that will barely start than one that won’t start at all, and if you’ve recently noticed that your mower makes you pull the starter rope harder, is prone to losing power while running, or starts using more gas than normal, the plug might be the problem. The clearest sign of plug trouble is when your engine will turn over but not actually start.

It’s a good idea to replace them at least once per year, and cleaning or replacing your plugs is a reasonable first step in resolving just about any starting problem. You can try gently cleaning a spark plug with fine-grit sandpaper, a file, or a soft wire brush, and you can use carburetor or plug cleaning spray to help. Just be gentle; damaged plugs will not be kind to your engine. There are other potential plug issues (wrong plug, bad gapping, or a cracked insulator) that might not be worth diagnosing, given that replacing the plug with a new (and correct) one addresses all these issues at once.

Ignition system problems: plug wires and coil

After dealing with the plug, it’s just about time to get serious with your diagnostics. But first, inspect your plug wires for obvious wear or damage. If they appear to be in poor shape, they probably are, which makes replacing them a good idea regardless of whether they are the full cause of your starting troubles. Next, it’s time to verify that your engine isn’t getting a spark. Ground your plug’s threads against a metal part of the engine itself and have someone attempt to start the mower as you observe the plug. If you consistently don’t see a spark, you should start looking at other possible causes.

If your plug wires are in good shape, ensure they’re making good contact with the spark plugs. Clean their terminals and, if necessary, squeeze the terminals slightly with pliers. If your mower has an on/off switch, use an electrical tester to make sure it’s functioning. Switches on mowers with pull cords can be slightly tricky to diagnose, so it might be a good idea to check the on/off function with a multimeter set to continuity mode. The point is that the continuity should change when the switch changes from on to off; some switches might close a circuit when on while others might open the circuit, but there should definitely be a change when the switch, well, switches. Check that the coil control wire connecting the engine to the coil isn’t abraded; if it shorts to the engine, the mower won’t start or run. Finally, consider replacing the coil. These are not user-serviceable, but they are affordable and critical to starting and running your mower.

Batteries die for a living

By far the most common element of the ignition system that can prevent a riding mower’s starting is the battery. Almost 20% — 11.8 million — of Google’s search results for the word battery include the phrase dead battery, because that’s what batteries fundamentally do: expend all their energy and die. And lawn mower batteries are almost always flooded lead acid batteries, which die more easily and more thoroughly than any other sort.

A lot of the work of fixing a battery problem is the same as properly maintaining the battery to begin with. That is, it’s stuff you should do regularly anyway. So, clean the battery terminals with a wire brush (clamp-on terminals might require a special type of brush, often cone-shaped). Use battery terminal cleaner if it’s necessary, though it rarely is. Make sure all electrical connections are clean and tight. Batteries that haven’t been maintained with a trickle or Smart charger while in storage, such as over the winter, will probably need to be charged and will sometimes even need to be replaced. If your battery is in good condition, check out your alternator and starter. Testing an alternator is simple on equipment with working headlights, as many riding mowers have. Just observe the lights. If they don’t dim when you turn off your engine, you probably have an alternator problem.

After verifying that you have a fully charged battery and a working alternator, check all the wires connected to the alternator and starter for damage. (You can test them with a multimeter if you’re suspicious of their condition.) If everything else checks out, test your solenoid and starter switch using the procedures outlined in this Briggs Stratton guide.

Fuel troubles

Every now and then you’ll see news about a possible perpetual motion machine devised in a scientist’s lab (or mind), but until you can pick one up at Home Depot, you’re going to be dealing with fuel for your lawn mower. This usually means gasoline, and there are a few common points of failure small engines can experience when trying to get fuel from the tank to where it’s needed for internal combustion.

First, make sure you have gas in the tank to begin with. This gets overlooked more often than you might guess, especially when you’re already half-expecting other mower problems and your brain primes the pump by framing everything in that context. Next, examine the age of the gas in use. Did you buy the mower used? Has it been in storage for more than a couple of months? Has the gas itself been sitting in the gas can for a while? Gas can go south in as little as a month, so if someone’s telling you it can sit for two years (a common number in mower lore) without chemical assistance or consequence, you should take your maintenance advice from someone else.

Mowers should be stored without gas or with an added fuel stabilizer (the aforementioned chemical assistance), to prevent such issues. Old gas clogs and damages fuel lines and carburetors, and won’t start an engine very well even if it makes it to the right place. If you already have old gas in your mower, you might need to remove and clean the fuel system components, as described here by Simple Green.

Fuel troubles: the fuel system

Replace your fuel filter regularly, especially if you’ve had old gas in your engine. If your engine has a fuel pump — and it probably does — it will reside between your fuel tank and the carburetor. When you’re out of options, check that it’s actually pumping by using a guide, like this one from Hello Practical.

There’s also the possibility that you aren’t availing yourself of some aids many lawn mowers have built into them to ensure the proper fuel/air mixture makes it to the engine. First, there’s the priming bulb: usually a clear, rubbery protrusion near the carburetor you can press. It will fill itself with fuel, injecting the fuel system with additional fuel as needed for starting.

You should also learn to use your engine‘s manual choke feature properly, if it has one. Many newer engines have an automatic choke, and mowers generally have either a choke or a priming bulb, as they both perform the work of enriching the fuel/air mixture for starting your engine. Start your engine with the choke on, then move it to the opposite position once the mower is running properly. Leaving the choke on will stall or potentially damage the engine. Also, check to see if the tiny hole in your gas cap is clogged. That hole creates a vent to allow fuel to move down the fuel lines, and if it’s clogged, your engine will be starved of fuel.

Air filters

Of course, when it’s time for things to blow up inside your engine’s cylinders, gas is only half of the story. Your choke (if you have one) tells the other half: You also need air to mix with the gas, and some mechanisms to help with the mixing. The choke makes the fuel/air mixture richer by restricting (temporarily) the flow of air through the carburetor. Once the engine is running, you should return the choke (and, thereby, the airflow) to normal. But there are a few possible reasons you might continue to have airflow problems.

The first is a dirty air filter. Like most parts of a lawn mower, the air filter is prone to becoming filthier than seems possible. This means it’s doing its job, and it also means the filter requires cleaning or replacing from time to time. A dirty air filter will cause an engine to misbehave in all manner of ways, including not starting easily or at all. Your mower has one or two filters, any of which may be either foam or paper. It’s usually better to replace a paper filter if possible, but otherwise tap it against a hard surface and blow it out gently from the inside with an air compressor.

Foam filters are a bit more involved. Start by tapping and blowing it out like a paper filter, then spray it thoroughly with a filter degreaser and allow to soak for 15 minutes. Rinse under clean running water and allow it to dry, and then apply a filter oil spray. To the extent it’s possible without damaging the filter, squeeze the filter to work the oil throughout. After a few minutes, reinstall the filter and wipe away any excess oil.

air: carburetor

Sometimes your fuel/air mix is off because the carburetor isn’t doing its job properly. In extreme cases, this could prevent the engine from starting. At that point, you must choose between cleaning and rebuilding the carburetor. Fortunately, these processes are mostly very simple. The standard process for cleaning a carb is to remove and clean (or replace) the air filter, then inspect the carburetor inside and out for stray debris. Finally, spray carburetor cleaner into the carburetor while the engine is running, per directions on the spray can.

If this doesn’t work — perhaps because the gum and gunk inside the carburetor is extreme as a result of age or being run with old gasoline — removing and rebuilding the carb isn’t as scary as it sounds. It’s basically a process of taking the carb off and then cleaning everything off of it that you can. It’s also a good idea to take some photos along the way, so you can be sure of how everything goes back together. Finally, just reassemble. Briggs Stratton has a good online overview of this process.

If this makes you too nervous, try adding a cleaning mixture of 4 ounces Sea Foam Motor Treatment and 8 ounces gasoline to the tank. Remove the spark plug(s) and then prime and crank or rope-pull the engine to draw the mixture into the carb. Allow it to sit 24 to 72 hours, then run the engine per Sea Foam’s instructions.

Odds, ends, and tips

There are a few other fairly common situations that can interfere with starting a mower. It’s never a bad idea to change your oil, but be sure to do it properly. Old oil, insufficient oil, overfilling with oil, or using oil that’s the wrong weight (viscosity) for the temperature outside can all contribute to difficult starting.

Keep your mower deck clean; an overabundance of grime and debris can slow blade rotation and hinder starting. Similarly, if you’ve run into something recently with your mower, inspect the mower deck to make sure the blades can rotate freely. A blade striking the deck can prevent the mower from starting altogether.

Finally, there’s the unpleasant business of the starter rope — that thing you yank on a mower with a recoil starter. There are two types of mower owners: those who have cursed the fortunes and questioned the character of mower manufacturers for inventing the recoil starter, and those who haven’t used a recoil starter at all. Common causes of starter rope problems include overfilling with oil and debris interfering with rotation in the mower deck, as mentioned above. Similar problems include bent mower blades and damaged mower deck shrouds. The cord may also be difficult to pull because the flywheel brake (controlled by a bar you must hold while using the mower) is stuck. Try loosening or tightening the cable, then repeatedly open and close the bar that engages the flywheel brake. If this doesn’t work, you might need professional assistance. If you feel up to it, Briggs Stratton has flywheel brake replacement instructions. Similarly, a hydrolocked engine (one that has seized after getting water in the engine) will normally require professional help, unless you’re up for these steps from Garden Guides.

Problems that aren’t (exactly) problems

Sometimes you’ll hear that the cause of some problem is a feature and not a bug, but the distinction isn’t helpful if you can’t start your lawn mower. The best example of this is a mechanism called a safety interlock (or often safety switch), by which your mower won’t run because some other thing isn’t quite right. For example, riding mowers that won’t start unless you’re sitting in the seat. Some cars have interlocks that prevent you from operating them if you’ve had a few beers, but fortunately mowers don’t have this feature yet, as it would prevent about 90% of Saturday afternoon lawn mowing from happening at all.

The safety switches on most riding lawn mowers include a seat switch that will not allow the engine to run unless the seat is occupied; a PTO safety switch that might prevent the blades from turning in certain situations and prevent the mower from starting when (for example) the blades are engaged; a brake switch to keep the mower from starting unless the brake is applied; and a reverse switch, that prevents mowing. Obviously several of these can prevent an engine from starting if they malfunction.

It might be tempting to disable some or all of these safety switches. Don’t — they’re there for good reasons. Unless you’re handy with a multimeter and circuits, dealing with faulty safety switches might be another job for a professional.

Troubleshooting guide

So, how do you know which of these problems is preventing your mower from starting? Let’s look at a few questions that will help you narrow down the most common problems and their solutions. If your mower is full of fuel but only runs for a few seconds, check the pinhole vent in your gas cap for obstructions. This could also be a sign of old gasoline. If the engine hasn’t been run in more than a month, treat the gas as suspect. You might also clean the carburetor and clean or replace the spark plug(s).

If your engine sounds like it’s cranking, but won’t fully turn over, you might have an electrical problem — possibly the starter. If you hear a clicking sound but nothing else, that similarly suggests starter, battery, or related problems. If you don’t hear anything at all when you turn the key, check the starter solenoid and its connections. This also might indicate issues with the battery, coil(s), ignition switch, or safety interlocks. Hearing nothing at all could also indicate that your mower is refusing to start because it is low on oil.

If the engine is cranking slowly, you probably have a failing battery. Check the battery and alternator. If your pull cord is difficult to pull, check that the flywheel brake is disengaged. Be sure you don’t have too much oil in the engine, and that it’s the correct weight for the season. Another sign the engine might be overfilled with oil is the presence of blue or white smoke when it does run. Black smoke, on the other hand, indicates the fuel mixture is too rich. Replace the air filter and check the choke mechanism.

John Deere lawn mower not getting fuel – Fixed

If you were troubleshooting the starting issue or extremely poor engine performance and came to the conclusion that your fuel system should be checked, this article is for you.

Here, I’ll walk you through general troubleshooting of the whole fuel supply system as well as extensive troubleshooting of every component in it.

Requirements

Park your tractor safely on an even surface, turn it off, take the keys out of the ignition and let it cool for a while.

Make sure that you’re following all the precautionary, safety measures when working with flammable materials, electricity, and machinery. If that’s the case, let’s proceed further.

Ensure that other systems are functioning properly.

Also, find out if you are caught up with basic maintenance like changing your air filter and spark plugs in time, adjusting the spark plugs (or how deep they sit), checking if the oil level is between two dots, checking if your valves have been adjusted in time and whether or not the oil is good according to the user manual (or YouTube videos on the same subject).

How to test the whole fuel system?

A quick way to test your fuel system is to spray some starting fluid in your air filter port (when the filter is off); if it helps your fuel system is inoperable.

Another way is to disconnect and ground your spark plug leads, close the choke, crank the engine a couple of times, then remove a spark plug and check for fuel at its tip. If there is fuel, your whole fuel system is fine; otherwise, your fuel system needs to be checked more thoroughly. You should dry your spark plugs afterwards with some cloth or paper (and it’s not a bad idea to perform this act before the test as well).

What your fuel system is comprised of?

The job of the fuel system is to ensure a steady and consistent supply of fuel to the combustion chamber.

The fuel system consists of a gas tank along with a tank cap, inlet fuel line, fuel filter, vacuum fuel pump, outlet fuel line, carburetor and some gaskets along with a few check valves.

Checking the gas

First, check if there is any gas in your tank by looking at the fuel gauge or shaking your lawn tractor “side to side” and listening for the gasoline splashing inside.

Now, if the gas was sitting in the tank for over one month, and you didn’t use any stabilizer fuel additives, you might want to change it by pumping the old one out with a fuel siphon pump or leaking it out through an inlet fuel line, previously disconnecting it from the inlet port of the vacuum fuel pump, and putting fresh gas in. A good way to test the fuel is to smell it through the gas cap; if it has a sweet vinegar odor to it, the fuel definitely went bad.

The fuel starts breaking down after 30 days and loses its effectiveness. over, modern gasoline contains ethanol in it, which draws condensate to it that makes it go bad even faster. The worst thing is, this condensate contributes to a fuel system clogging up (all of it, including the carburetor and the fuel pump). Ethanol also dries up your rubber/plastic fuel lines which contributes to cracks and breakages in them, it also can contribute to oxidative/chemical damage to your carburetor and damage little solenoids, rubber plugs, and gaskets.

Inlet fuel line, the gas tank cap, and the fuel filter

To test your inlet fuel line for clogging or cracks, your fuel filter, and your fuel cap (for ventilation); you’ll need to gently unplug the fuel line from the inlet port of your vacuum fuel pump, by unclamping the clamp on the inlet pump port with pliers, previously preparing a container for testing the fuel flow and squeezing the fuel line with pliers for preventing an unwanted fuel leakage.

Then, place the disconnected end of the inlet fuel line so that flaw from it would go into your test container and unsqueeze the fuel line to test the flow. If there’s a strong enough influx of fuel and there are no fuel leakages through the fuel line, your inlet part of the fuel system is good. If there were some leaks through the line, you would have to change your fuel line.

If there is no fuel flaw or if it is very weak, you might want to unscrew your fuel cap and try again. If there is a flaw after unscrewing, you need to change your fuel cap.

If that didn’t help, you might want to change your fuel filter. If the problem persists, you’ll need to completely take your inlet fuel line off your tractor and unclog it by spraying compressed air into it and then spraying some degreaser.

The Vacuum fuel pump and outlet fuel line

First, you need to unplug your spark plug and ground it where the fuel won’t reach it.

To test your vacuum fuel pump and outlet fuel line, you need to unplug the outlet fuel line from your carburetor, squeeze it to prevent unwanted leakage, and direct it into the prepared container to test the fuel flaw (which could be very strong).

Then, crank the starter to see if the fuel is running adequately strong. If it isn’t, you have a problem with either your outlet fuel line or your vacuum pump.

You may want to inspect your vacuum pump for cracks or physical damage to determine if it’s bad.

You can also remove your outlet fuel line, flush it with pressured air, then a degreaser and give it one more chance.

If there’s no flaw, your vacuum fuel pump is dead or clogged very badly

Carburetor Blockage

If the rest of your fuel system was fine, yet you’re still not getting fuel into the engine, you should test your carburetor.

In order for you to check your carburetor, you will have to completely uninstall it and take it apart. If it’s clogged up, a thorough cleanup is due. You will need different brushes, a good carburetor cleaner, and also not to forget all those jets (including the needle) and the float bowl.

However, if it’s not just clogged up with fuel residue or dirt and has some serious oxidative/chemical damage from the ethanol in the fuel (especially if it was sitting for a couple of months), it’s better to replace it with a brand new one altogether; because even the ultrasound clean-up may not fix the issue as the physical size of these intricate passages and jets won’t be proper ever again, which may render it completely inoperable.

Another part where the problem may lie is the diaphragm, in which case you need to change it.

You should also check the choke linkage, it should be stranded for the choke to work. And check the electrical carburetor shutoff valve for 12 V with a voltmeter when the key is in the ignition.

Prevent:

First of all avoid using fuel with more than 10% ethanol in it as it draws moisture to the fuel system, which speeds up rusting of its metal parts. It also affects chemically the metals and especially plastic and rubber components.

Most of the fuel system problems lie in improper storage and lacking maintenance.

So to prevent these problems in the future, change your fuel filter in time and prepare the machine for storage properly.

To prepare your fuel system for storage, you should start using stabilized fuel as you approach storage time. In fact, you should always use stabilizing additives to protect your fuel system components.

However, if you still have some amount of not-stabilized fuel sitting in the tank, you should either run it out or pump it out with the siphon pump. Then fully fill the tank with fresh fuel previously mixed with the stabilizer additive and let the mower run for a couple of minutes (before storage).Good luck!