Lawn Mower Repair The How to Guide to Fixing It Yourself
Despite care and maintenance, machines can suddenly develop a problem that needs to be fixed. Your lawn mower is a hard-working machine and sometimes that hard work results in damage that needs to be undone.
Knowing how to do minor repairs on your lawn equipment yourself can save you some time and money. With that in mind, we’ve created this guide on lawn mower repairs for you. To get your lawn mower serviced by experts, come to one of our John Deere dealership locations throughout Central and Southern Florida.
Starting Problems
If your mower isn’t starting or starts and stops, then you probably have a clogged carburetor. The most common way to end up with a clogged carburetor is to leave fuel in the mower when it’s not in use for a long time. The liquid parts of the fuel evaporate, leaving behind a sticky, gooey mess that clogs your carburetor and prevents the engine from starting. Use a carburetor cleaner to clean it thoroughly.
Another culprit behind starting issues in lawn equipment is a damaged spark plug. Check to see if it has any signs of wear or damage. Use a spark plug tester to check if it’s defective; if you don’t see a strong spark between the tester’s terminals then it’s time to replace the spark plug. If there is carbon buildup in the electrode, an electrode is damaged, or the porcelain insulator is cracked, replace the spark plug.
Battery Problems
If your lawn mower battery keeps dying on you, one or more cells in it may have died. Use a charger to charge the battery. If it doesn’t hold the charge, you need to get a new battery. Sometimes, though, it may be that other components are at fault, not your battery. Use a multimeter to check that the charger is giving proper voltage output. A multimeter will also let you check the alternator which recharges the battery and gives voltage to your mower when in use.
Blade Problems
If the blades on your lawn mower do not engage, you could have a problem with the PTO switch. A multimeter will let you check if the switch is damaged and needs to be replaced. If your switch is fine, the problem may lie in your PTO clutch. This clutch manually disconnects the engine from the blades. When the clutch solenoid is powered, it uses the drive belt to move the rotation of the mower blades. If there is anything wrong with the PTO clutch, it will need to be replaced as it can’t be repaired.
Gas Leak Problems
One common lawn mower repair involves gas leaks. To determine what you have to fix, you need to check where the leak is happening. If the bottom of the carburetor is leaking fuel, the carburetor bowl gasket might be missing or dried out. Replace this gasket. Another reason behind a gas leak could be the float needle not shutting off fuel. This needle opens and closes the float valve to allow fuel into the float bowl. If it’s damaged, the fuel will fill the carburetor until it overflows. Replace it if it’s damaged.
If neither of the above is the problem, examine the fuel shut-off valve. The fuel lines should be tightly affixed to the valve and shouldn’t have any cracks, tears or holes in them. If a fuel shut-off line or the fuel shut-off valve is leaking, replace it immediately. Do not attempt to patch or cut and rejoin a fuel line.
Free Mower in the Trash. Serious Problem or Easy Fix?
Overheating Problems
Overheating is another common issue that occurs in lawn mowers but it is easily avoidable with a little care. Your mower has an air-cooled engine with cooling fins fixed into the engine’s cylinder head and short block. These fins keep the engine cool while your mower is busy at work. Sometimes bits of grass, leaves, and debris can clog these fins so you need to clean your mower at proper intervals or after heavy use to ensure this doesn’t happen to your machine.
Smoking Problems
It can be scary to see your lawn mower start to expel thick black smoke but what this indicates is that your carburetor is ‘running rich’, i.e. it is getting too much fuel. Check to see if the carburetor float is jammed in the open position and fix it if it is. Another reason behind black smoke is the carburetor choke valve being closed. It needs to be open once the engine is running or the engine won’t get enough air to create the right fuel-air mix.
We hope this list helps you identify and perform common lawn mower repairs. If you can’t really tell what’s wrong with your mower or want to purchase quality lawn equipment, come to Everglades Equipment Group at one of our 17 locations in Florida. We’re always happy to whip old machines into good shape and help people choose the right machines for their needs. We are proud to serve the areas of Central and South Florida!
Lawnmower Won’t Start? Do this.
Bad gas or a dirty carburetor are the most common reasons for a lawnmower that starts hard or runs rough.
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A lawnmower that won’t start, especially when taken from storage, is almost always due to one problem: bad gas.
Storing a lawnmower in the fall without adding gasoline stabilizer to the fuel tank can cause the fuel to break down and plug the fuel passages. If fixing that problem doesn’t help, there are a few others that can help fix a lawnmower that won’t start, as we explain here.
How to Fix a Lawnmower That Won’t Start
Replace the Bad Gas
Over time (like the six months your lawnmower sat in your garage over the winter), the lighter hydrocarbons in gas can evaporate. This process creates gums and varnish that dirty the carburetor, plug fuel passages and prevent gas from flowing into the combustion chamber.
The carburetor bowl below formed corrosion and deposits during storage, which can easily plug fuel passages and prevent the engine from starting.
Storing equipment without stabilizing the gas can lead to deposits that foul the carburetor or injectors.
Ethanol-containing gas can absorb water from the atmosphere, which can lead to phase separation, which occurs when ethanol and gas separate, much like oil and water. Ethanol that has absorbed enough moisture and has sat long enough can foul the fuel system and prevent the engine from starting.
No matter how many times you yank the pull cord and pollute the air with your advanced vocabulary, the lawnmower won’t start if it’s trying to run on bad gas.
In extreme cases, evaporation of lighter hydrocarbons can change the gasoline’s composition enough to prevent it from igniting. The gas may be fueling the engine, but it doesn’t matter if it won’t ignite.
Bad Gas in Your Lawnmower? Here’s How to Fix It
If you neglected to add gasoline stabilizer to the fuel prior to storage, empty the tank and replace with fresh gas. If the tank is nearly empty, simply topping off with fresh gas is often enough to get it started.
On some mowers, you can easily remove and empty the fuel tank. Sometimes that’s more trouble than it’s worth. In these cases, use a fluid extraction pump or even a turkey baster to remove the bad gas. You don’t need to remove all of it; but try to get as much out as possible.
Clean the Carburetor
You’ve replaced the fuel, but your lawnmower still won’t start.
Next, try cleaning the carburetor. Remove the air filter and spray carburetor cleaner into the intake. Let it sit for several minutes to help loosen and dissolve varnish and gums.
Remove the air filter and spray carburetor cleaner into the intake. Let it sit a few minutes to loosen deposits.
On some carburetors, you can easily remove the float bowl. If equipped, first remove the small drain plug and drain the gas from the bowl. Remove the float bowl cover and spray the float and narrow fuel passages with carburetor cleaner.
This kind of “quick-and-dirty” carburetor cleaning is usually all it takes to get the gas flowing again and your lawnmower back to cutting grass.
If not, consider removing the carburetor from the engine, disassembling it and giving it a good cleaning. Be forewarned, however: taking apart a carburetor can lead to nothing but frustration for the uninitiated. Take pictures with your phone to aid in reassembly. Note the positions of any linkages or the settings of any mixture screws, if equipped. If you’re at all reluctant, visit the servicing dealer instead.
Consider replacing the carburetor altogether. It’s a fairly simple process on most smaller mowers and it’s often less expensive than taking it to the dealer.
Direct compressed air from the inside of the air filter out to remove debris that may be reducing airflow and preventing the lawnmower from starting.
Top Reasons Lawn Mower Not Starting — Lawn Mower Troubleshooting
Clean/Replace the Air Filter
With the air filter removed, now’s the perfect time to clean it.
Tap rigid filters on a workbench or the palm of your hand to dislodge grass clippings, leaves and other debris. Direct compressed air from the inside of the filter out to avoid lodging debris deeper into the media.
Use soap and water to wash foam filters. If it’s been a few years, simply replace the filter; they’re inexpensive and mark the only line of defense against wear-causing debris entering your engine and wearing the cylinder and piston rings.
An incorrectly gapped spark plug can prevent the engine from starting. Set the gap to the specification given in the owner’s manual.
Check the Spark Plug
A dirty or bad spark plug may also be to blame. Remove the plug and inspect condition. A spark plug in a properly running four-stroke engine should last for years and never appear oily or burned. If so, replace it.
Use a spark-plug tester to check for spark. If you don’t have one, clip the spark-plug boot onto the plug, hold the plug against the metal cylinder head and slowly pull the starter cord. You should see a strong, blue spark. It helps to test the plug in a darkened garage. Replace the plug if you don’t see a spark or it appears weak.
While you’re at it, check the spark-plug gap and set it to the factory specifications noted in the lawnmower owner’s manual.
If you know the plug is good, but you still don’t have spark, the coil likely has failed and requires replacement.
Did You Hit a Rock or Other Obstacle?
We’ve all killed a lawnmower engine after hitting a rock or big tree root.
If your lawnmower won’t start in this scenario, you probably sheared the flywheel key. It’s a tiny piece of metal that aligns the flywheel correctly to set the proper engine timing. Hitting an immovable obstacle can immediately stop the mower blade (and crankshaft) while the flywheel keeps spinning, shearing the key.
In this case, the engine timing is off and the mower won’t start until you pull the flywheel and replace the key. It’s an easy enough job IF you have a set of gear pullers lying around the garage. If not, rent a set from a parts store (or buy one…there’s never a bad reason to buy a new tool) or visit the dealer.
My Lawnmower Starts But Runs Poorly
If you finally get the lawnmower started, but it runs like a three-legged dog, try cleaning the carburetor with AMSOIL Power Foam. It’s a potent cleaning agent designed to remove performance-robbing carbon, varnish and other gunk from carburetors and engines.
Add Gasoline Stabilizer to Avoid Most of These Problems
Which sounds better? Completing all these steps each year when your lawnmower won’t start? Or pouring a little gasoline stabilizer into your fuel tank?
Simply using a good gasoline stabilizer can help avoid most of the problems with a lawnmower that won’t start.
AMSOIL Gasoline Stabilizer, for example, keeps fuel fresh up to 12 months. It helps prevent the lighter hydrocarbons from evaporating to reduce gum and varnish and keep the fuel flowing. It also contains corrosion inhibitors for additional protection.
I have a five-gallon gas can in my garage from which I fuel two lawnmowers, two chainsaws, two snowblowers, a string trimmer, an ATV and the occasional brush fire. I treat the fuel with Gasoline Stabilizer every time I fill it so I never have to worry about the gas going bad and causing problems.
You can also use AMSOIL Quickshot. It’s designed primarily to clean carburetors and combustion chambers while addressing problems with ethanol. But it also provides short-term gasoline stabilization of up to six months.
Use a Good Motor Oil for Your Lawnmower
Although motor oil has no bearing on whether your lawnmower starts or not (unless you don’t use oil at all and seize the engine), it pays to use a high-quality motor oil in your lawnmower.
This is especially true for professionals or homeowners running expensive zero-turn or riding mowers.
Lawnmower engines are tougher on oil than most people realize. They’re usually air-cooled, which means they run hotter than liquid-cooled automotive engines.
They often run for hours in hot, dirty, wet conditions. Many don’t have an oil filter, further stressing the oil.
In these conditions, motor oils formulated for standard service can break down, leading to harmful deposits and reduced wear protection.
For maximum performance and life, use a motor oil in your lawnmower designed to deliver commercial-grade protection, like AMSOIL Synthetic Small-Engine Oil.
Its long-life formulation has repeatedly demonstrated its ability to safely exceed original equipment manufacturer (OEM) drain intervals in the toughest conditions. It provides an extra measure of protection when equipment goes longer between oil changes than is recommended by the OEM.
Signs You Need to Repair or Replace a Mower That Isn’t Cutting It
Lawn mowers have striking similarities to cars. Engines, transmissions, sparkplugs, and filters all wear out or need replacing from time to time. The debate between replacing or repairing your lawn mower often comes down to the same principle: Is your lawn mower totaled or is it worth the cost of repairs?
Luckily, even some of the most common mower issues are manageable DIY fixes. Here’s how to decide whether it’s time to repair or replace your mower.
When to Repair Your Lawn Mower
Whether you’ve owned a riding mower for just a couple of years or inherited your dad’s push mower, the cost is key. The cost of a new lawn mower ranges from 160 to 3,000. Lawn mower tune-ups and repair costs, on the other hand, go anywhere from 10 to 250.
In other words, your model will play a large role in whether it’s worth hanging on to an old clunker. Here are some common scenarios to consider.
The Warranty Still Applies
According to Consumer Reports, manufacturer and extended warranties for mowers range between two and five years. Make sure you read the fine print before heading to the store, however. Some warranties only cover material and manufacturing defects—not the cost of common upkeep like filter replacements. Still, if you just purchased a mower and it’s already on the fritz, it’s worth checking if it’s a general imperfection.
It’s Time for a Tune-Up
Give your lawn mower some TLC at the end and the start of the grass-growing season. A simple tune-up can help you avoid unnecessary repairs or eventual replacement. Be sure to:
- Empty the gas tank before the winter
- Sharpen your blades
- Remove grass buildup from base of the machine
- Switch the oil
- Oil the axle
- Clean the filter
You can also bring your machine to an experienced local lawn mower repair person who can check some of the more common fixes below as well and start off your season with success.
You Need a New Spark Plug or Ignition Switch
The spark plug and ignition switch are both low-cost replacements that you can often manage on your own. Spark plugs only cost about 10 and ignition switches cost between 10 and 25.
Signs of a faulty spark plug may be that your mower doesn’t turn on at all or that it turns off suddenly. Ignition switch problems can keep your mower from turning off.
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It’s Time to Replace the Filter
If your lawn mower has suddenly turned into a gas-guzzling creature, you may need to clean or replace your filter. Even if you already replaced it during your annual tuneup, filters can become clogged mid-season if you’re working your mower more than usual. A clogged or damaged filter can force the motor to work overtime, thus using up more gas.
You Need Gas or a New Battery
Both gas-dependent and eclectic cordless lawn mowers depend on a power source. If you can’t get your lawn mower to start, it could be something as simple as topping up your gas or replacing the battery.
Lawn mower batteries range from 35 to 250, still typically less than most new battery-powered mowers.
Take the guesswork out of keeping your lawn pristine throughout the growing season
Another Small Part Needs Fixing
In reality, there are many small parts that are both affordable and relatively easy to order online and replace yourself. However, always read your mower’s user manual to purchase the right part and to properly disconnect the power before attempting DIY repairs.
Common cost-effective lawn mower repairs that beat replacement includes:
- Dirty or broken cooling fins
- Broken or stuck flywheel brake
- Blades blocked by debris
- Cracked oil tank or oil tank cap
- Cracked gas tank or gas tank cap
- Damages drive belt
When to Replace Your Lawn Mower
Do you have a sneaking suspicion that it’s time to put your lawn mower out to pasture? There are, unfortunately, a few major repairs and some scenarios that aren’t always worth the cost of the mower.
It’s Than 10 Years Old
The standard longevity of a lawn mower ranges from seven to 10 years. Mechanical push mowers are so simple that they could last much longer if you keep the blade’s shape and frame oiled. Once you make it past the decade mark with gas and electric mowers, there may be a better model on the market for both efficiency and for keeping upkeep to a minimum.
The Engine is Shot
One of the most important elements of a mower is its engine. And much like a car, replacing it can rival the cost of the mower itself. If the mower needs full replacement—and not just the replacement of individual parts—you’re looking at materials costs alone upwards of 1,000.
You Need a New Transmission
A new transmission will cost less than a new engine—usually between 400 and 500—but if your lawnmower is nearly the end of its estimated lifespan—and if you only need a 500 new model—then it’s best to start fresh.
The Model No Longer Meets Your Needs
If you recently moved to a home with a multi-acred backyard and still have a small push mower, it may be time to upgrade. Not only will the blades, oil, filter need more frequent upkeep, but you could save money by upgrading to an eco-friendly eclectic model that can handle large lawns with less power.
On the other side of the coin, let’s say you’ve finally decided to switch to local landscaping services that bring their own riding mower. If you have a large machine that’s just going to rust in the shed, consider trading in your mower for a small model that requires less fuss.
You Spend Time Repairing Than Mowing
Do you find yourself ordering lawn mower parts online every time you take your machine out of the shed for a season? While DIY repairs can save time and money, reconstructing all the small mechanisms of your mower can add up over time. Be sure to keep a record of how much you spend on your mower in a given season and double-check that it didn’t add up to the cost of a shiny new model.
Is it time to repair your lawn mower or and lawn equipment?
Maybe you went to start your mower but….
It wouldn’t start? Or Maybe your mower was fuming smoke?
Perhaps your tractor just wasn’t running properly?
No worries, it happens to all of us. But how do you repair lawn mower when it breaks down?
Here are a few things you should know.
Most Local Repair Shops Prefer Professional Equipment
Here’s a secret that you may not have realized it yet. Most shops will specialize in repairing commercial equipment that the pros use. They are often not interested in fixing your residential mower, so it’s best to save their time and yours, and ask a few questions before dropping your mower off.
Here are a few good questions to ask before sending you mower in for repair:
- Ask them what their labor rate is,
- Are they are interested in repairing residential equipment,
- Most importantly how backed up are they.
Pro Tip!
Think about it, when it comes to working with equipment, it is no wonder that most shops don’t want to repair residential lawn mowers. Professional lawn mower repairs are more predictable, and problems occur less often. On the other hand repairing residential lawn mowers can be more of a hassle.
That is why you have to find the right lawn mower repair service.
Finding the Right Lawn Mower Repair Shop
Here is a tip, big box stores have often found the best pros for repairing lawn mowers they sell.
Call up your local lawn and garden center at Home Depot or Lowes, and ask the department manager, where they send their warranty repairs to. These big box retailers have to assist in processing the warranty claims for the equipment they sell. Because they need efficient repairs, they work with the better lawn mower repair shops in your town.
These lawn mower repair shops often offer the best quality work. Better yet these repair facilities are quick, and reasonably priced. They are often much, much more affordable, because they work with your type of equipment all the time. This enables these repair facilities to offer quick diagnosis, and fast repairs.
Once You have Found a Mower Repair Shop
Now that you have found the shop that is not backed up, and that is willing to work on your equipment, be careful to not spend more on repairing the equipment than its worth!
Ask for a ballpark price, many places may offer free estimates for lawn mower repair work. So be sure to ask how much it’s going to be to repair your equipment. You would be amazed how easy it is to spend 600 to repair a riding mower that is worth 300, and all the while you could buy a brand new one for 700.
You can often save a bit of time and money if you can diagnose the problem yourself. However, when you don’t know what you are doing you may do more harm than good. If you are a bit handy, you can check out our article on diagnosing common lawn mower problems.
Some Recommended Repair Shops
After being in the lawn care industry for over 15 years, I have found a number of great repair facilities in the places I worked, and by word of mouth from my fellow landscapers. I have written a few articles about the lawn mower repair facilities in these areas.
- Tampa or St. Petersburg Florida, I recommend these shops for repair as well as equipment purchases.
- Here are the Top 5 Repair Shops in Charlotte, NC
- And If you live in Atlanta Georgia you are in luck! There are a lot of amazing lawn equipment mechanics, and lawn mower repair shops. Here are the Top 10.
Want to Recommended Your Local Repair Shop?
Of course. we could not cover all the great lawn equipment repair facilities in the country. If you know of a great place tell us on @YourGreenPal
We would love to hear from you!
Lawn Mower Still Broken? Try This!
While you are waiting to get your equipment repaired, jump on GreenPal and line up a pro to cut the lawn until you get it back. Signing up is simple, and you can get several lawn care bids quickly. Seriously, we work with some of the best landscapers across the country, check it out!
Hi, I’m Gene Caballero and I’m the co-founder of GreenPal. At GreenPal, we’re helping hundreds of thousands of Americans solve one of the trickiest problems: a reliable, fast, and affordable way to get lawncare taken care of. On behalf of GreenPal, I’ve been featured in the Indianapolis Star. the Sacramento Bee. Entrepreneur. Inc.com. and dozens more. Please feel free to say hi on or connect with me on LinkedIn.