How to Start a Push Lawn Mower. Choke on lawn mower

How to Start a Push Lawn Mower

This article was co-authored by Jeremy Yamaguchi. Jeremy Yamaguchi is a Lawn Care Specialist and the Founder/CEO of Lawn Love, a digital marketplace for lawn care and gardening services. Jeremy provides instant satellite quotes and can coordinate service from a smartphone or web browser. The company has raised funding from notable investors like Y Combinator, Joe Montana, Alexis Ohanian, Barbara Corcoran and others.

There are 8 references cited in this article, which can be found at the bottom of the page.

This article has been viewed 669,609 times.

Starting a lawnmower can be intimidating, especially if you’ve never done it before. While there are some differences between lawnmowers, the same basic technique works for many of them. With a little practice and some elbow grease you’ll be starting your lawnmower like a pro in no time!

Starting the Lawnmower

Prepare to start the lawnmower. Move the lawnmower to an open, grassy area. Clear away any children’s toys or rocks. [1] X Research source

Make sure your mower has gas and oil. If your mower has a 4-stroke engine, you can check the oil by opening the oil fill cap or dipstick. If your mower has a 2-stroke engine you’ll need to mix oil in the gas. Make sure you mix the the right kind of oil with the gas, and in the proper ratio for your engine.

  • If the spark plug isn’t firmly attached, refer to your user manual. You may need to take the lawnmower to a mechanic to have it fixed.
  • Have a mechanic change the spark plug once a year. [2] X Research source
  • If the mower is cold, set the choke. The choke helps provide a richer fuel-air mixture to the engine, which helps it stay running until it warms up. Once the mower has been running for a few minutes turn off the choke.
  • If it doesn’t start or make any noises at all, the spark plug may not be attached. Check the spark plug and try again.
  • If it sputters and sounds like it’s trying to start (but doesn’t) you may not have enough gas in the tank.

Diagnosing Problems

  • You MUST disconnect the spark plug before doing this. Otherwise, you risk the lawnmower starting with your hands inside of it.
  • If the starter is still stuck after clearing out the debris, see a mechanic.
  • Check your user manual to see if it addresses this issue. Some models have “quirks” that can be easily fixed if you know how to do it.
  • Always be careful when changing the height of your lawnmower. Make sure the mower is off and the spark plug is disconnected.

Taking Care of Your Lawnmower

  • If your lawn mower doesn’t have a dipstick attached to the oil lid, look for a “fill” line inside the oil tank. If the oil level is below that line, add more oil.
  • If you decide to change the oil yourself, remember to properly dispose of the leftover oil by taking it to a recycling facility. Used oil can contaminate groundwater and damage the environment.
  • Never attempt to work on machinery alone. If you get hurt, no one will be around to help you.
  • Avoid filling the gas tank too high. If you do, the gas may spill out and cause a fire.
  • If you’re not sure what kind of gas to use, refer to your user manual.
  • To care for your lawn during a hot summer, mow high and water deeply and infrequently. [11] X Research source
  • Choose a fertilizer for your lawn depending on whether you want to achieve growth, replenish missing nutrients, or develop stronger roots. [12] X Research source
  • Once you figure out what works for your lawn, stick to that plan and see it through.

Community QA

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It is likely that the fingers on the starter clutch are staying open when you pull it so they are being tapped by the metal cup on the fly wheel that they grab onto when the pull starter is being engaged. It’s a typical sound for older used mowers and nothing to be too concerned about. If it continues after it’s started it could be the result of a rod knocking in the engine, at this point replace the engine or the mower.

Thanks! We’re glad this was helpful. Thank you for your feedback. As a small thank you, we’d like to offer you a 30 gift card (valid at Use it to try out great new products and services nationwide without paying full price—wine, food delivery, clothing and more. Enjoy! Claim Your Gift If wikiHow has helped you, please consider a small contribution to support us in helping more readers like you. We’re committed to providing the world with free how-to resources, and even 1 helps us in our mission. Support wikiHow

My Lawn Mower Starts Then Dies: What’s Wrong?

Ahhh…the smell of fresh-cut grass. There’s really nothing like it. However, it’s pretty frustrating to be all ready to tackle those tall green blades only to have your mower fire up and then sputter out. If your lawn mower starts then dies, you want a quick answer about what’s to blame, and what to do to fix it. I’ll share the 4 most common causes to this mower problem and what you need to do to address each.

When your mower starts then dies it can feel like you’re alone, but this problem is more common than you might think, and the fix can be an easy one.

Let’s take a look at the four most common reasons behind that false start and how to fix them.

Causes for Lawn Mower Starting then Dying

If your lawn mower starts, runs briefly, then dies these are the four most common reasons that’s happening:

  • Dirty carburetor / clogged carburetor bowl
  • Old gasoline that has gone bad
  • Dirty or defective spark plugs
  • Too much oil in your resevoir

Below I’ll get into each potential problem, why it can result in a mower that starts then dies, and what you should do to fix it.

Dirty Carburetor or Clogged Carburetor Bowl

When your lawn mower starts then dies, your carburetor is most likely involved somehow.

Think about it. If you live in a northern region, your mower sits all winter … waiting months without any action.

And, if you live in a more temperate zone, your mower works hard year-around.

In both cases, your carburetor is going to need a little TLC.

What’s so important about the carburetor?

Your engine needs a steady flow of gasoline to run correctly. The carburetor is responsible for mixing gas with just the right amount of oxygen to create combustion.

This combustion supplies a continuous rotation of the crankshaft that is necessary to run the mower’s engine.

If your carburetor is dirty or the carburetor bowl is clogged, the process above is compromised, and your engine may start up, but it will not run properly and may die shortly after you pull the cord.

How do I fix it?

Your dirty carburetor needs a good blowout with an aerosol can of carburetor cleaner. This will cost you less than 10 and will last for a season or two. I use the WD-40 Specialist Fast Acting Carb/Throttle Body Parts Cleaner (Amazon link). This cleaner uses a solvent formula to breakdown carbon contaminants, leaving your carburetor clean and gum-free. I give my mower a shot of that every time a mow, right before pulling the cord, and recommend that you do the same.

The only drawback to this particular cleaner is it does not have a straw for targeted spraying. If you need a more precise application, Gumout makes a cleaner (Amazon link) that will do the trick with its jet spray applicator.

You can purchase either product locally, or online.

Unscrew the carburetor bowl and give it a once over with the cleaner. Be sure to clean the screw and hole with the carburetor cleaner as well. This is where the directional spraying straw is particularly handy. When reattaching the bowl, don’t over-tighten the screw. This could strip the threads enough to distort the seal.

What I Do

For carb maintenance, give a light spray near the air intake hole for your mower’s engine just before you start it up. This is typically just behind the air filter. Remove the filter, give the hole a spray, then replace the filter.

When you start the mower, it’ll be pulled into the engine and clean deposits in your carb.

Old Gasoline in Your Mower

You know your mower can’t run without gasoline, but the quality of the gas is equally important.

If the gas in your mower has been sitting inactive for a while, evaporation has most likely created a damaging residue.

start, push, lawn, mower, choke

This residue leaves particles that clog your mower’s internal parts.

The end result is restricted gas flow, which means your mower can start and die shortly thereafter. Sometimes, your mower won’t start at all.


How do I fix it?

If your mower tank is less than half full of old gas, you might try adding new gas to dilute the impurities. If the old gas is more than half of a tank, it would be best to siphon it out and fill the tank with fresh gasoline.

In both cases, adding a stabilizer such as Sta-bil Fuel System Stabilizer (Amazon link) is a Smart idea. Stabilizers prevent the clogging residue for up to two years, and at around 10 a bottle, they are an inexpensive additive that can keep your mower running like a champ.

Always read the directions to know the proper fuel to stabilizer ratio for your mower.

What I Do

I used to mix Sta-bil into my fuel, but now I just pay a little extra for 4-cycle TruFuel – an ethanol free gas product that can sit for years without going bad.

It’s more expensive than regular gas mixed with Sta-bil, but a couple of larger cans will get my Honda self-propelled mower (this one from Home Depot if you’re curious) through the mowing season up here in New England, and I like the peace of mind that comes with knowing my mower and snow blower always start on the first pull, and I don’t have to worry about bad gas giving me problems when I’m ready to mow or need to clear the driveway.

You can buy it online, or locally at Home Depot or some local hardware stores.

Dirty or Defective Spark Plugs

Spark plugs supply the “spark” that ignites the air/fuel mixture in your engine.

This small explosion makes your engine produce power.

The spark plugs are an essential component of your mower’s ignition system. If they are dirty or faulty, they will not spark, and your mower will not start, or may start and then quickly die.

How do I fix it?

Your mower’s spark plug(s) are easy to find. In most walk-behind mowers they’re covered with a black cable and right in the front of your mower.

You’ll need a socket wrench of the right size to remove your plug (check your manual to find the correct size for your mower/spark plug).

If your spark plugs are not too heavily coated with build-up, you can try cleaning them. You should never clean a spark plug with a shot-blasting cleaner. A wire brush and appropriate cleaner will do the trick if the plug is just dirty.

However, if your mower’s spark plug looks filthy or appears to have a dark carbon residue, you might be better off replacing.

This is an easy job and it’s inexpensive – a new spark plug with be 8-9 and your size is probably available locally.

What I Do

Spark plugs should be replaced every year or two for problem-free mowing, and I do mine annually as part of my spring mower maintenance.

I get a new air filter and change the oil in my mower at the same time. This runs me about 20 total, takes me about 15 minutes, and keeps my mower in perfect working condition.

Replacing Your Spark Plug

Removing your spark plug is an easy job anyone can do. Simply unhook the spark plug wire and remove the old plug with a spark plug socket.

Replacing a spark plug can be a bit more challenging for a first-timer, but I still consider it an easy job.

Use a spark plug gauge to measure the gap between the two electrodes at the tip of your spark plug. Check for the specifications for your model to know the recommended size of the gap.

If necessary, use a spark plug gauge to adjust the gap by gently bending the curved electrode. When the gap is correct, the gauge will drag a bit as you pull it through the gap.

Now you can install the new plug and attach the spark plug lead. Be careful not to over-tighten on installation.

If you have never done this before, there are several videos online that can be of great assistance, but my advice is that as soon as it starts to feel snug, give it no more than another quarter turn to prevent damage.

Too Much Oil in the Mower’s Reservoir

If your carburetor is clean and the spark plugs are firing, the problem might be too much oil.

I believe it’s human nature to want to over-fill a lawn mower’s oil reservoir, especially if you’re not particularly handy. You feel so accomplished that we’re doing the job yourself that you go overboard and over-fill the tank.

It happens, and it’s not the end of the world (or your mower).

White smoke coming out of the engine is a tell-tale sign that excessive oil is the culprit.

start, push, lawn, mower, choke

If a lot of smoke is coming out, your mower might be running, but not for long. In this case, the excess oil will eventually drown out the engine and cause it to die.

How do I fix it?

This is actually an easy fix. If you have too much oil, you just need to drain some. You can use a siphon, or (if you have a walk-behind mower) you can tip your mower and drain the oil from the hole where you add it.

What I Do

I’m guilty of overfilling the oil tank sometimes too, so I’ve learned to go slow when I add oil. I check, and check again with the dipstick and gradually bring the level up to the proper place.

If you have overfilled your oil tank, I advise that you use a dipstick to measure the amount of oil in the reservoir before removing it, and then again after to make sure you get the right level.

Not enough oil is another (and more serious) problem, and you would not want to inadvertently trade one issue for another.

After draining some oil and checking to see if you have an adequate amount, start the mower again.

If the mower fires and stays running without the billowing puffs of white smoke, you have corrected your problem.

Lawn Mower Starts Then Dies: When it’s Time to Call a Professional

If you have tested all of the methods I’ve shared for fixing your lawn mower that starts and then dies, hopefully your problem is solved.

But if not, it might be time to throw in the shop towel and call a professional.

The following are other issues that could be keeping your mower from running properly.

Serious Reasons Your Lawn Mower Starts Then Dies

  • Worn out carburetor: If your carburetor is more than dirty, it might be time to replace it.
  • Faulty choke: Unless you are extremely handy, identifying this problem and restoring the delicate balance necessary to get your engine purring like a kitten is another issue for the experts.
  • Gas tank or gas line blockage: Anytime your gasoline is not getting to the engine, your mower will not run properly. A blockage of any kind that prevents the constant flow of gas is a problem that might take a trained eye to identify and fix.

The average weekend warrior with limited knowledge on the matter will probably feel more comfortable hiring someone with the experience and the tools to get the job done right.

I recommend that you start by checking your mower’s warranty. If it’s covered, a repair may not cost you anything. Some companies will send someone right to your home, or come to pick up your mower to save you time.

If your mower isn’t covered by warranty, find a local small-engine repair shop that has good reviews. These guys can fix almost anything, and their are typically lower than you’d expect.

Preventing Mower Problems

The best way to ensure your mower will fire up and run like a champ is to put preventative measures in place.

I have tips for winterizing your mower, and a spring maintenance checklist that you can check out if you’d like to learn more.

  • Clean your air filter regularly (replace it annually).
  • Change your spark plugs every 1-2 years.
  • Keep stored oil and gasoline clean. Use a stabilizer in your gas to keep it fresh for up to two years, or pay extra for 4-cycle TruFuel.
  • Keep your engine clean with an engine degreaser.
  • Use the dipstick and don’t overfill your oil reservoir.
  • Keep your carburetor clean with a carburetor cleaner spray.

Performing regular maintenance on your mower is the best way to keep it running smoothly, and investing a few bucks per year in this is worth it.

You’ll avoid headaches, repair costs, and your mower will last a long time, starting right up when you need it.

If you do encounter a problem with your lawn mower, decide if you are comfortable with trying to fix it yourself.

Lawnmower Won’t Start? Auto Choke Easy Fix! #baldeagle242 #autochoke

If the issue seems to be something beyond the basics, don’t hesitate to call a professional. There’s no shame in this, and sometimes do-it-yourself repairs are just not worth the time, energy, or frustration.

But if you are up for the challenge of fixing the problem yourself, the above guidelines provide a good starting place, and online videos may also be useful. I think YouTube is a great resource.

The main thing is that you get your mower fixed so you can get out there and make your lawn the envy of the neighborhood.

Which Choke Symbol Is On Or Off On Your Lawn Equipment?

If you find it difficult to identify the “on” and “off” positions of a choke switch, you are not alone. Sometimes, it could take a light turning on to be able to tell if a switch is turned on or off, but in the case of a choke without a bulb, what would the indicator be? Which symbol on a choke is on or off?

The choke symbol is in the on position restricting air into the engine when the lever points to an angled or horizontal line. This can also be designated by the words ‘Choke’, ‘Full Choke’, or ‘Start’. When the choke is off or disengaged the lever points to a vertical line or the word ‘Run’.

There is a lot more to know about how a choke works and what these symbols or words mean. The concept is not hard to grasp, so read through the rest of this article and you will know all you need to know about small engine chokes.

What Position Is ‘Choke On’?

It can be confusing for those not very familiar with mower or trimmer engines to know what the use of a choke is for and what the positions mean. Understanding the simple operation of a choke can help to know what the position of the choke lever does.

First of all, why is it even called a choke? The choke function on your lawn equipment (or any other electrical equipment) is used to control the air that enters the cylinders and mixes with the fuel.

In clearer terms, when the choke is on, the airflow is restricted and when it is off, air can enter freely. This means that the status of the choke on your lawn equipment can determine how well it functions when in use.

I will get into this in more depth later on, but essentially turning on the choke keeps more of the fuel fumes in the engine and restricts most of the airflow that would dilute the fuel vapors. This concentrated fuel environment helps with starting and warming up the engine.

Now that we have an idea of how the choke functions, it is ideal to know how to identify the “on” and “off” position of the choke on your lawn equipment.

How Do You Know If The Choke Is On Or Off?

Here RustySkull Productions shows the ‘Choke’ or ‘Choke On’ position symbol here also labeled ‘Start’.

In most cases, the choke is a small lever or switch on one side of the lawn equipment. When the lever is pushed up or forward to a diagonal or horizontal line, the choke comes on. When the choke is on, the carburetor gets blocked by a plate-like obstacle.

At this point, you can say that the system is “choked” and when the lever is pulled down (or backward) to a vertical line, the choke goes off. The obstacle is removed and air can flow into the vessel where it gets combined with fuel.

If your lawn equipment suddenly goes off or sounds like it’s struggling to stay on, you may want to check the choke lever before calling a technician. If the air-fuel ratio is imbalanced, the engine would struggle to function properly so you always want to have your choke lever at the right spot when using the equipment.

Another note: many times in the middle of a long job the engine would start to sputter on me, making me adjust the choke and suspect something could be wrong with the fuel to air ratio. Though I was normally right about the air ratio in the engine, it was normally that I had let it run out of fuel.

Embarrassing at the time, but funny now.

One other side point that is interesting to note: Researchers are always looking for better ways to use fuels and engine design. For now, chokes are the main way to control air and fuel entering a carburetor, but in the future this may not be needed.

In a technical paper published on, engineers and researchers alike are finding ways to make engine starting easier on users and more energy efficient. Today, you can even see automatic chokes on many higher end models from most brands.

start, push, lawn, mower, choke

Though, these come with their own problems, as most innovations do.

Is It Bad To Leave The Choke On?

The answer to any question that asks about leaving a choke on is definitely, no. When starting the choke is only used to help prime the engine. When operating a mower or other small engine tool, running with the choke on indicates or can cause problems. Chokes should be turned off for storage.

Leaving The Choke In The On Position During Starting

When the choke is on, fuel combustion is optimized for use.

In other words, the air-fuel ratio is controlled and the carburetor can function adequately. This indicates that it is not only good but important to turn on the choke before using the equipment in question.

This position helps with starting and warming up the engine.

Starting Tip: What I normally do to start a small engine with a choke is to hit the priming bulb 5 to 10 times depending on the equipment with the choke on full (—). I then pull the cord or turn the ignition switch (key) until the engine sputters. Then I reduce the choke to half ( / )and start the engine. After a few seconds of warming, I turn off the choke ( | ) to let the engine run normally with optimal air intake.

Now let’s look at the problems it could cause or indicate when leaving the choke on during operation is attempted.

Leaving The Choke On During Operation

Now, when in full operation, you may want to pull down (or back) the choke lever a little. As long as the choke remains on, more fuel would be used and if you don’t mind using up a little more fuel to mow, you could leave it on throughout the operation.

However, this may not be ideal for mowing procedures that last up to an hour or longer. Keeping the choke on for that long could not only cause the engine to use up more fuel, but it could also increase pollution and cause the system to heat up more than necessary.

That being said, this is not the intended or optimal use of a choke. Most normally operating engines will sputter and smoke on full choke once started and warmed up. There will also be decreased power and movement on mowers that are properly tuned and working on extended full choke use.

  • There is some sort of blockage in fuel lines, the fuel filter, or air filter reducing the amount of fuel reaching the carburetor.
  • The fuel used has an octane mixture that is less than optimal due to the presence of water or other additives.

Finding and fixing these issue can increase fuel efficiency and operation. For the purposes of our discussion here, it can also cure the problem causing your mower, blower, or weedeater only running on full choke.

Do You Leave The Choke In The On Position When Storing?

After the lawn has been mowed to your satisfaction, what do you do? Turn off the equipment and leave the choke on so you don’t have to worry about it the next time?

The simple answer to this is “turn off the choke”.

The purpose of the choke is to warm the system when it is in operation and when the lawn equipment is turned off, it is advisable to turn off the choke as well.

Even leaving the choke in the ‘half’ position is not a good idea when storing. In some cases, the choke lever may be pulled down halfway after starting with it in the full position the mowing equipment has warmed up to reduce fuel combustion.

Understanding The Role Of The Choke In A Lawn Mower

The choke feature on your lawn equipment is designed to practically choke the carburetor and restrict the airflow. This is to allow the right amount of air and fuel to mix during the operation of the equipment. As long as the choke is on, fuel enters the vessel, and the longer it is left on, the more fuel is used in the procedure.

If the fuel supply is too much, it affects the operation of the lawn mower. You might think that since the lawn mower operates on fuel, giving it more fuel supply should be the way to go.

This brings back a memory of when I got my first lawn mower. I was sure that the higher the concentration in the fuel supply determined the speed of the lawn mower. I was wrong.

My actions caused for some rough running of the mower engine. It can even in rare cases cause perminent damage to the carburetor. When the fuel supply is overwhelming, the carburetor can develop leaks.

If the carburetor leaks without you knowing, think of the possible damage it could cause. This is why you have to know the role of a choke in your lawn mower.

The same goes for air flow in the carburetor. If the air supply is cut off, it could also affect the engine from functioning the way it was made to.

If you notice any irregularities with your lawn mower’s idle or normal operating sound and feel after ruling out choke positioning, I recommend that you get your small engine mechanic to take a quick look at it.

When the choke lever is pushed up, the choke is on and when it is pulled down, it goes off. You could also pull the lever halfway down during operation or halfway up at the beginning of the operation. The colder the engine, the more fuel it needs, and thus, the higher the lever should go.

If you have determined that none of these positions cure sputtering or stalling, it is time to look elsewhere for the solution.

The Final Touches On The Choke On Symbol…

The choke on symbol for most small engines looks like a horizontal ( — ) or diagonal ( / ) line. It also can simply say ‘Choke’, ‘Full Choke’, or ‘Start’.

The off symbol for most small engine chokes is represented by a vertical line ( | ) or the word ‘Run’.

Mathew has worked in landscaping professionally for over 10 years. He is a grandpa and frequently interviews other experienced landscapers and lawn care experts who are also grandpas for these articles.

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Why Your Lawn Mower Runs Better With Choke On and How To Correct It

One of the most common conditions that happen to lawnmowers is running only (or at least better) when the choke is on. While it might not seem like an issue at first, it will drain more fuel and can lead to other complications if you run it like this all the time. However, many people disregard this and run the mower anyway. So, is it bad to run a mower with the choke on?

If your mower runs better when the choke is on, it means the fuel/air mixture isn’t properly adjusted. This can be caused by too much air or too little fuel getting into the chamber. It’s bad to run a mower with the choke on because it can damage the engine.

Most mowers can’t even run with the choke one, but you should check what the problem is if yours does. No machinery should operate outside the normal functioning system. Before you start dealing with it yourself, you should first know what a choke is and how it works. Then you can detect the issues and deal with them accordingly.

What is a choke on a mower?

Internal combustion engines often have a choke valve. It’s a valve that allows you to manually limit the amount of air getting into the carburetor, making the mixture heading into the chamber richer with fuel. It’s usually used during the ignition to allow an easier start. These kinds of engines are common in all kinds of vehicles, including automobiles.

On a lawnmower, the choke is the same thing as it is in a car. It’s a valve used to block the air intake. Usually, there’s a choke lever on the mower that you need to press during the ignition to get it started. Sometimes, it can feel like your mower runs better if you keep the choke on all the time, not just during the ignition.

start, push, lawn, mower, choke

Whether your mower can run with the choke on or not depends on what kind of a choke lever you have. You can have a choke lever separate from the throttle lever or have only the throttle lever with a choke mode integrated into it. In both cases, if your mower runs only with the choke on, or at least runs better in that position, there’s a problem you should adhere to.

Why does my mower run better with the choke on?

There are several reasons why your mower might be running better with the choke on. Keep in mind that none of the possible problems are too hard to handle yourself, but if you feel insecure about your repair skills, take your mower to a professional and repair it.

If your mower is running better when the choke is on, it means the mixture in the chamber is lean. Too much air is getting into the chamber, so when you “choke” the air intake, the mixture stabilizes, making the mower run better. Air leaks are quite common and can happen anywhere around the chamber. Most commonly, it’s the carburetor.

Sometimes, it can be the other way around. Due to a clog, or a malfunction on the carburetor, it is possible that not enough fuel is getting into the mixture. Therefore, lowering the amount of air inside the chamber levels it to a degree, making the mower run better. You would feel a significant drop in performance, though, and the engine might overheat soon.

Finally, there might be contamination in the fuel system. That means a foreign body caused a clog somewhere in the system: the carburetor, the fuel intake area, the fuel tank, etc. If none of these are the case, then you might need to switch to a fuel with a lower alcohol percentage. It costs a bit more but works a lot better regardless of the type of your mower.

Is it bad to run a mower with the choke on?

You should never run your mower with the choke on for longer than five minutes, which is the approximate warm-up time on most mowers. If you do, it can lead to increased fuel consumption, faster wearing of the elements of the fuel system, engine overheating, and finally, significant engine damage.

Even if nothing significant happens to the engine, operating outside of the normal conditions for a longer period can lead to issues with other parts of your mower that aren’t necessarily a part of the fuel and ignition system.

While none of these things might happen right away, it’s much more cost-effective to deal with the issue right away. Regardless of what type of malfunction it might be, it will not be an expensive fix-up. In most cases, you can fix it yourself without paying anything extra.

How To Fix It

No matter how experienced you are, if you are not a professional mechanic, I always advise everybody to see a professional and ensure everything runs as it should. But, if you decide you want to do it yourself, fixing the choke problem on your mower isn’t hard in any case.

If there’s an air leak somewhere and too much air is getting into the chamber, try finding where the leak is. Tighten all the valves and pipes, leading air into the carburetor. Inspect the fuel lines for cracks, and if you have a manual fuel primer, check it for cracks or leaks as well.

If there’s contamination somewhere in the fuel system, you need to clean it thoroughly. Use a carb cleaner to clean the carburetor properly from debris and varnish. Drain the fuel tank and clean it thoroughly as well. Make sure all the fuel lines and pipes are clean and put everything back together.

If there are no cracks or leaks, and the entire system is clean, the only other reason can be a broken part of the mower unrelated to the fuel system, or the fuel you are using doesn’t match the engine. Using non-alcoholic fuels usually does the trick.

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