A smoking lawn mower is never a good sign. Whether the smoke is blue, white, or black, here’s how to identity and address the issue without the help of a professional.
By Glenda Taylor and Bob Vila | Updated Sep 24, 2020 1:40 PM
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Q: Recently, my mower started billowing smoke when I powered it up, so I shut it off immediately. Why is my lawn mower smoking? And is it a fire hazard? I want to know how to proceed so I don’t harm the machine.
A: Your lawn mower can emit smoke for numerous reasons—many of which don’t require the services of an expert. A homeowner can usually identify the reason for a smoking lawn mower by gauging the color of the Cloud coming around the engine, then fix it accordingly before lasting damage occurs. Keep in mind that all mowers with internal combustion engines contain the same basic parts, but the configuration of those parts varies widely, depending on manufacturer and model. Consult your owner’s manual if you’re unsure how to access a specific part of your lawn mower’s engine.
White or blue smoke may indicate an oil spill on the engine.
If you’ve recently changed the oil in your mower and the engine is emitting white or blue smoke, it’s possible that some of the oil spilled onto the engine. Similarly, you could’ve spilled oil on the engine by mowing on a slope greater than 15 degrees or tipping the mower on its side. The smoke may look disconcerting, but it’s completely harmless. Solve the problem by restarting the mower and allowing the spilled oil to burn off. If you tip the mower often for cleaning or maintenance, check your owner’s manual to determine the best way to reduce the risk of oil leaks.
An overfull oil reservoir may also cause white or blue smoke.
Ensure you didn’t overfill the mower by checking the oil level with the dipstick located on the reservoir. To do this, remove the dipstick cap, wipe off the stick with a rag, and reinsert it into the reservoir. Then remove the dipstick once again and determine the oil level in comparison to the recommended “fill” line on the stick. If the level is too high, drain the oil (consult your owner’s manual for instructions), then refill the reservoir with it. Start checking the oil level with the dipstick after you’ve added about ¾ of the amount recommended in the manual. Continue to add small amounts of oil until the level matches the recommended “fill” line. Also note that using the wrong grade of engine oil may cause blue or white smoke. Consult the owner’s manual for the exact type of oil recommended for your mower.
Black smoke may indicate that the mower is “running rich,” or burning too much gasoline.
Your lawn mower’s carburetor regulates the ratio of gasoline to air mixture. If the carburetor isn’t getting enough air, the mixture has a higher percentage of gasoline, which can create black exhaust smoke. It’s possible that a dirty or clogged air filter is preventing sufficient airflow into the carburetor. Try replacing the air filter. (Note: air filters vary by mower model; view example air filter on Amazon.) Next, run your lawn mower for a few minutes. If the black smoke still appears, the carburetor might need to be adjusted in order to increase airflow. Either take the mower to a professional or adjust the carburetor yourself with instructions in your owner’s manual.
Take your mower to a repair shop if necessary.
If the previous steps don’t correct blue or white smoke, your mower could have a more serious problem, such as an air leak in the crankshaft (the cast iron or cast aluminum case that protects the moving parts of a mower’s engine). Continuing blue or white smoke could also indicate that some of the engine’s components or seals are worn out and need replacement. Similarly, if black smoking still persists after you’ve replaced the air filter and adjusted the carburetor, you could be facing a more serious mechanical issue. All of these problems require the help of a professional. If your mower is still under warranty, check with the manufacturer for the location of the nearest servicing dealer; problems stemming from a factory defect or poor workmanship may garner free repairs. If your mower is not covered under warranty, a reputable small-engine repair shop should also be sufficient to get the job done.
The best cordless lawn mowers in 2023
Looking for the best cordless mower? Browse our experts’ pick, from budget to premium models.
A lawn mower may be one of the first purchases we make when getting a garden of our own, but that doesn’t mean finding a good quality one is easy. There are so many models and brands on the market to choose from, including corded electric and petrol, but as their range increases and fall, cordless, battery-powered models are an increasingly popular option.
Light and compact compared with traditional petrol models, cordless mowers are simple to use, easy to manoeuvre around the garden, and have none of the maintenance and servicing needs or costs of petrol lawnmowers. Powered by a rechargeable lithium-ion battery, which charges up quickly and won’t lose power in storage, they’re also quiet and emission free.
To compare these cordless mowers against other types of mower, we’ve reviewed the best lawn mowers, robotic lawn mowers, electric lawn mowers and push mowers, too. And if your lawn needs a bit of attention, our experts have tested a range of the best manual and powered aerators and scarifiers.Keep edges looking neat with our pick of the best strimmers, the best garden shears and the best lawn edging, and if you’re thinking about somewhere to store your new mower, our comprehensive guide to choosing the best garden shed will be helpful.
For your next DIY project, have a look at the best cordless drills.
The best cordless mowers to buy at a glance
Cordless mowers. Buyer’s Guide video
Many thanks to Rosie Yeomans and Sparsholt College for their help in making this video.
Getting the best cordless lawn mower for you means ensuring it has the correct cutting width, range of cutting heights, and weight plus a battery run time that matches the size of your lawn. We’ve tested a range of cordless push mowers, putting them through their paces across a range of grass and terrains, to help you find the right one for your garden.
Each mower has a detailed list of pros and cons for clarity and has been rated according to set up and storage, handling, mowing and value for money. Every mower in our round up below has scored a minimum of four out of five stars, so you can buy with confidence.
In every review we award outstanding products our coveted Best Buy award. To see these and the others we recommend, browse our pick of the best cordless lawn mowers, below.
Best Buy cordless mowers
Husqvarna Aspire LC34-P4A
Our rating: 4.9 out of 5
- Cuts even long grass with ease
- Battery level visible while mowing
- Small and compact for easy storage
- Part of the POWER FOR ALL cordless range
Part of the new Husqvarna Aspire cordless range, which includes a hedge trimmer, pruner and leaf blower, this 34cm mower is powered by an 18V POWER FOR ALL ALLIANCE battery and charger. These are interchangeable with tools in other leading brands such as Flymo, Gardena and Bosch so if you also invest in tools in these ranges, you’ll only need to buy the bare tool and won’t have different batteries and chargers taking up space in the shed.Great for small gardens the mower comes ready to go, there’s no assembly or handles to attach, and it folds down to a compact size when you’re finished, with a telescopic handle that folds completely flat over the body of the mower. It can then be stood up against a wall or hung up, and even comes with a handy hook. The 30l grass bag also flattens down to take up very little room and can be hung on the mower. The Aspire is light, with a carry handle so that lifting it up steps or into other areas is easy and it has an adjustable handle to suit different height users. It’s comfortable and easy to manoeuvre around the garden and has just four cutting heights to choose from, ranging from 25-65mm and changed easily with a single lever on the body of the mower. It cuts grass quietly and smoothly and has an automatic boost that increases blade speed when you’re mowing in tougher, longer areas that works well. You can hear it kick in when you push the mower into longer grass and unlike other cordless mowers that can cut out, just carries on cutting the grass. While you mow the battery charge level is always clearly visible so you know how much battery you have left and when it needs charging. It comes with a two year warranty and we awarded it a BBC Gardeners’ World Magazine Best Buy in 2023 for ease of use.
Specs: Battery: charge time. 95 mins; run time. 500sqm. Cutting: width. 34cm; height. 25-65mm. Grass box. 30 litre.
Buy the Husqvarna Aspire C34-P4A cordless mower from Husqvarna and Sam Turner
Our rating: 4.5 out of 5
- Easy to assemble and use
- Comfortable padded handle
- Choice of mulching or collecting clippings
- Interchangeable battery with Greenworks 24V family
Ideal for smaller gardens this sturdy, great value cordless mower is easy to put together, well thought out and simple to use. Thanks to a padded handle it’s comfortable to push, although it did feel a little short for our taller tester, and it’s light and easy to manoeuvre around trees and beds and borders. There are five cutting heights to choose from, adjusted with the simple lift of a lever and it offers the choice of collecting clippings in the 30 litre fabric grass bag or inserting the mulching plug and leaving them on the lawn to break down and feed the grass. It mows well but doesn’t like very long grass, with the battery cutting out occasionally but its long lasting brushless motor offers a a decent run time of 46 minutes and it charges in two hours. Plus, as part of the Greenworks 24V family, both the battery and charger are interchangeable with all the other tools in the range, saving you money if you invest in more in the future. We awarded it a BBC Gardeners’ World Magazine Best Buy for the best budget cordless mower in 2023.
Specs: Battery: charge time. 120 mins; run time. 46mins. Cutting: width. 33cm; height. 25-70mm. Grass box. 30 litre.
Yard Force LMG37A 40v 37cm
Our rating: 4.8 out of 5
- Rear roller
- Double folding handle for easy storage
- Quickest charge time
- Part of the Yardforce GR40 cordless range
This sturdy mower has a 37cm cutting width and useful features including a rear roller for those much desired stripes. Awarded a BBC Gardeners’ World Magazine Best Buy in 2022 for small to medium lawns, clippings are collected in the large 40 litre fabric grass bag. It offers a wide choice of seven cutting heights, from 25-75mm, and is easy to fold away at the end of the day. The 40V battery is quick to charge, taking just 50 minutes and when full it has the capacity to cut a 400m2 lawn.
Specs: Battery: charge time. 50 mins; run time. 400sqm. Cutting: width. 37cm; height. 25-75mm. Grass box. 40 litre.
Buy the Yard Force LMG37A 40V 37cm cordless mower from Yard Force, Amazon and Wickes
The Best Self-Propelled Lawn Mowers in 2023 for Making Your Yard Work Easier
These lawn mowers drive themselves, taking the load off you in the process.
By Roy Berendsohn Published: Mar 21, 2023
One of the perks of the warm-weather season is getting to spend time outside. If you own your own home and have a yard, it’s very likely that in order to enjoy your outdoor space, you need to mow the lawn. The larger the yard, the more work it will be to maintain. If you have a lot of grass to cut, you’d be wise to consider a self-propelled lawn mower especially now that there are a ton of sales just in time for Memorial Day.
The primary difference between a standard push mower and a self-propelled mower is that the former moves when you push it, and the latter essentially moves itself with only your guidance. Once the engine is running, all you have to do is squeeze a handle or push a lever and the mower will start moving forward with you as you walk.
Turning the mower around is your job, but once you have your heading, just keep the drive handle squeezed and escort the mower down the path, no pushing necessary.
Self-propelled law mowers take power off the engine and route it via a belt to a pulley on the transmission and axle. When you move the drive control lever on the mower handle, you tension the belt, causing the pulley to turn, and this drives the transmission, moving the mower forward.
Move the drive control lever back and the tension is released, the pulley stops turning, and the mower stops moving forward. The belt-driven transmission is a time-tested design to power the mower and take the load off you in the process.
What to Consider
A mower is like many consumer products in that the more features a manufacturer adds, the more expensive it becomes. But a longer or more eye-catching list of features isn’t necessarily better. Sometimes less is more. Here are the most important to keep in mind.
Front-wheel drive mowers tend to be less expensive than rear-wheel drive units. They can be easier to turn because you don’t have to disengage the drive wheels to do so. Simply push down on the handlebar to raise the front wheels off the ground. However, their traction isn’t as strong on hills or when the bag is full, as there isn’t as much weight over the drive wheels.
Rear-wheel drive mowers do cost more and aren’t as easy to turn, as you do need to disengage the drive—but this isn’t too much of a hassle. Rear-wheel drive mowers shine on hills and inclines, and when the grass bag is full. In either scenario, weight is shifted rearward and over the drive wheels, which enables superior traction, thus making the self-propel more effective.
An engine as small as 125 cc can power a mower, but most are somewhere in the 140 cc to 190 cc range. A large engine helps when powering through tall, lush grass or in extreme conditions, such as with a side discharge chute in place and mowing tall weeds in a border area. Also, the extra torque provided by a larger engine can improve bagging when the going gets tough (tall, leaf-covered grass in the fall). But if you mow sensibly and pay attention to deck height—and especially if you don’t let your lawn get out of control—an engine between 140 and 160 cc has more than enough power to get the job done.
A mower can have all four wheels the same diameter (7 to 8 inches), or it may have rear wheels that range from 9.5 inches to 12 inches in diameter. Larger rear wheels help the mower roll more easily over bumpy ground.
Free Smoking Lawn Mower. Not an Engine Issue
With some mowers you can start the engine with the twist of a key or the press of a button. It’s a great option, but a luxury. Keep the mower engine tuned and use fresh fuel with stabilizer added to it, and you’ll never have trouble starting.
Any number of mechanisms can control a mower’s ground speed—a squeeze handle, a drive bar that you press forward, even a dial. There’s no single right answer here. Look at the design and think about how you like to work. For example, if more than one person will be using the mower (and not all of them are right-handed), a drive control like that on a Toro Personal Pace mower might be the answer. Just push down on the bar to make it go faster. Let up on the bar to slow down.
A mower that can bag, mulch, and side discharge is known as a three-function mower, the most versatile kind. Two-function mowers bag and mulch or mulch and side discharge.
Mowers will typically have one, two, or four levers to control the deck height. Single-lever adjustment is the easiest to use, but it requires more linkage, which adds weight and complexity. If, for some reason, you find yourself varying deck height frequently, it’s a good option. Otherwise, two or four levers work just fine.
Only Honda makes a gas-engine mower with a high-impact plastic deck (there are battery mowers that have plastic decks). Otherwise, mowers generally have a steel deck, and a few manufacturers—Toro, for one—offer a corrosion-resistant aluminum deck. An aluminum deck won’t rot the way a steel deck will, but you still need to keep it clean.
This is a hose fitting mounted on top of the mower’s deck. When you’re done mowing, hook up a hose and run the mower to power wash the underside of the deck. We’ve had mixed results with these, but they’re better than just letting a mass of dried grass clippings accumulate.
expensive mowers come with a more durable bag with more dust-blocking capability. If you bag a lot, especially leaves or other lawn debris in the fall, then you need a mower with a higher quality dust-blocking bag. Having said that, if you rarely bag, the standard one that comes with a mower will last you the life of the mower.
Also called wide-area mowers, machines in this subgroup help homeowners better reconcile their need for more power and speed with the fact that they may not have enough storage for a tractor or zero-turn mower. A typical residential walk mower has a single-blade deck that cuts a swath from 20 to 22 inches wide. Wide-cut mowers (built for homeowner use) have either a single blade or, more typically, a pair of blades, cutting from 26 to 30 inches with each pass. Some of these are rated for light commercial use and have larger decks, in the 32-inch range, and engines that start at 223 cc and go up to about 337 cc.
Wide-cut mowers typically employ gear or hydrostatic drive transmissions, and they have top speeds of about 4 to 6 miles per hour. At their fastest, they move so quickly you have to trot to keep up with them. Needless to say, they’re overkill for small yards; only opt for one of these if you’ve got a significant plot of land that you need to keep tidy, but not one so large that you’d be better off going with a full-on riding mower.
How We Tested and Selected
We compiled this list based on Popular Mechanics mower testing and our knowledge of the lawn mower market at large. For our testing, we put mowers through the paces using our standard Popular Mechanics methodology: We cut turf grasses such as fescues and blue grass and rougher non-turf grasses like Timothy, clover, orchard grass, and wild oats, all in both normal and shin-deep heights. We mow uphill, downhill, and across the faces of hills. The maximum slope we cut is about 30 degrees.
That may not sound like much, but it’s about all you can do to stand on it, let alone push a mower up it or across it. We mow damp and wet grass to test general cutting performance and whether clippings accumulate on the tires. And we cut dry and dusty surfaces to see how well the bag filters under less-than-optimal conditions.
Honda HRN 216VKA
Honda mowers enjoy a sterling reputation. Having tested their walk and self-propelled mowers for the last 30 years, we feel confident that Honda’s entry level mower is a great choice for homeowners looking for power and durability. The HRN features a GCV 170 gas engine that’s built to withstand long hours of operation.
If you do your own maintenance (and most owners who buy this class of product do), you’ll appreciate the easily accessible spark plug and the fuel shutoff valve that enables better winter storage. Close the fuel shutoff and run the mower until it sputters to a halt. This will clear the carburetor of any gasoline, which will prevent the ethanol in it from disintegrating and causing running issues later on. Open the shutoff valve in the spring, add some fresh gasoline, and the mower should start easily.
All this maintenance stuff is great, but we can also tell you that our past test findings on other Hondas prove that their cut quality is outstanding for cleanliness. Sharp blades deliver a velvet-like finish. And their bagging ability is also quite good, in the same league with other well-bagging mowers from Toro.
In all, if you take mowing seriously, you should enjoy this Honda. If you have a little wiggle room in your budget, consider the Honda HRX, which features a mower powerful engine and a composite deck that won’t rust and is renowned for its durability.
One note is that Honda has announced that it will cease selling lawn mowers in the United States after this year—so if you’re considering buying one, best do it sooner rather than later.
Ryobi 40V lawnmower won’t run, stops, intermittent fix, problem solved
Toro Recycler 60-Volt Max Lithium-Ion
Toro mowers have garnered more recommendations from us than any other brand for two reasons: build quality and cut quality. These were amply demonstrated in our testing as the Recycler turned in the best ratio of cut area per amp-hour of battery in the self-propelled category, while at the same time not skimping on cutting, mulching, or bagging quality.
We attribute this outstanding mower performance to three features, all upgrades to the previous version of this machine. First, the air vent at the front of the mower deck seems to improve mulching and bagging performance. Toro calls it Vortex technology, a design that increases air flow under the deck. This helps to stand the grass for a cleaner cut, which improves mulching performance, and also allows better airflow into the bag when collecting the clippings.
Next, the company’s redesigned “Atomic” blade configuration appears to assist the air flow and clipping movement. Finally, the three-phase, 60-volt motor is exceptionally efficient, resulting in a large cut area for a single battery.
Toro has maintained features that make this mower work: rear wheel drive, a one-piece deck that’s all steel (no plastic nose), 11-inch wheels to help it roll over roots and crevices, and the same fold-forward handle that was an industry breakthrough when it was introduced some years ago.
Ryobi 40-Volt Brushless Self-Propelled Mower
This is one of Ryobi’s top-of-the-line mowers, and it’s American-made construction is something we wish we saw more of. It delivers a tremendous cut area with its two 6-Ah batteries providing a total of 12-Ah of capacity, and its X-shaped blade leaves a pristine surface in its wake.
Ryobi estimates the design should provide 70 minutes of run time; we didn’t time our cut, but it strikes as plausible. Its rear-wheel drive and reasonably aggressive tire tread pattern provide good hill climbing and sidehill cutting performance, and its bagging on all surfaces (level, sidehill, and uphill) is also commendable.
Other ease-of-use features include an easily installed or removed bag that mounts and dismounts straight up and down through the handle; deck adjustment is quick and easy thanks to a single-level deck height adjustment. The straight edge deck is polypropylene; it will never rust and needs very little care other than basic cleaning.
Toro TimeMaster 30 in. Briggs Stratton Personal Pace
The Toro Timemaster 30-in. mower has been around for several years and has earned a reputation as a sturdy workhorse for homeowners who want to cut down on their mowing time. It’s also used by some professionals as well. A few years ago the Timemaster got a slightly more powerful Briggs and Stratton gas engine, so it should have no issues powering through most demanding mowing jobs.
The Timemaster is rear-wheel drive and features Toro’s Personal Pace drive system that’s used on many of its self-propelled mowers. This allows the mower to move at your speed by simply pushing down or releasing the handle, which is spring-tensioned.
With a 30-in. deck, Toro claims the Timemaster will help you reduce your mowing time by about 40% compared to using a standard-sized mower. You can mulch, back, or side discharge with the Timemaster, and the handlebar can be locked in a fully vertical position to reduce space consumption in storage.
If you have half an acre to a full acre of lawn to mow and prefer the experience of a walk-behind mower versus a tractor or zero-turn, the Timemaster is worth a look.
Craftsman mowers have been doing very well in our tests, so we can recommend this one because it’s so much like the many other of the brand’s models that we’ve tested. If you’re looking for a good blend of maneuverability and power, you’ll get it with this mower. Its front drive helps move it along and makes it easy to turn.
It’s important to note that front-drive mowers do lose some traction when running uphill, particularly with a full grass bag. But if your slope is less than 20 degrees, and you’re not bagging uphill, you’ll be fine. The side discharge will also help you handle tall grass. Adjust the two deck levers to bring the mower up to full height and have at the rough stuff.
The fact that this mower bags, mulches, and side discharges is a plus, enabling you to handle a wide range of mowing conditions, from early spring and late into the fall. Three-function mowers like this are our preference for that versatility.
Toro Super Recycler Self-Propelled Lawn Mower
This is a beauty of a mower, with a cast-aluminum deck and a smooth-running Briggs Stratton 163-cc engine. We tested the Honda engine-equipped version, and it was effective at both bagging and mulching, even in moist grass.
Equipped with rear-wheel drive and the Personal Pace system (the farther you push the drive bar, the faster the mower goes), it’s an effective hill climber and moderately effective on sidehill cutting. It has relatively small 7.5-inch tires on all four corners, which causes this Toro to bump up and down a bit on washboard surfaces. But the good news is that it’s equipped with a far higher quality tire than we’re used to seeing these days. We didn’t notice them pick up any grass on moist surfaces.
Other features we like include its forward-fold handle that has a built-in shock absorber that Toro calls a Flex Handle Suspension, and a high-quality grass bag that loads through the handle, from the top.
Are there special maintenance considerations with self-propelled mowers?
Yes. Both front- and rear-wheel drive mowers typically feature a drive belt, which can crack or wear out over time. Fortunately these belts are not difficult or particularly expensive to replace.
Secondly, you may have to replace the drive wheels occasionally. These wheels are driven with gears. there are typically teeth on the inside diameter of the drive wheel that line up with a gear on the axle. These teeth can wear out, especially if they are made of plastic. Higher-end mowers may feature drive wheels with a metal gear that meets the metal axle gear, which improves longevity of these components.
My lawnmower says I don’t ever have to change the oil, but just add oil when needed. Is this OK?
It’s not a good idea to never change the oil in your lawn mower. In a lawn mower, same as a car, oil degrades over time and is less effective at reducing heat and friction in metal components. Changing the oil in your lawn mower is easy to do and will significantly increase its service life. For most homeowners, changing the oil at the beginning or end of each mowing season should be sufficient, though there is certainly no harm in doing it more often.
Roy Berendsohn has worked for more than 25 years at Popular Mechanics, where he has written on carpentry, masonry, painting, plumbing, electrical, woodworking, blacksmithing, welding, lawn care, chainsaw use, and outdoor power equipment. When he’s not working on his own house, he volunteers with Sovereign Grace Church doing home repair for families in rural, suburban and urban locations throughout central and southern New Jersey.