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

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

Family Handyman

Introduction

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

What to Do if Your Lawn Mower Won’t Start

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

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

Project step-by-step (6)

Check the Gas Tank

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

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

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

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

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Check the Spark Plug

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

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

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Check for Debris in the Mower Deck

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

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

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Check the Air Filter

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

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

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Check the Carburetor

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

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

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

Check the Fuel Filter

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

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

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

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

How to adjust Predator 212 carburetor?

A lot of your engine problems such as the engine not idling or the engine dying out can be easily solved with minor adjustments in the carburetor.

In this article, you can learn how to adjust the idle screw and the air/fuel mixture screw for both the stock carb that comes with the predator 212 (or other small engine Honda clones) and the Mikuni carb and its clones.

Stock Carburetor Adjustments

The stock carb that comes in with the Predator 212 or other clone engines will look similar to this:

Idle screw

The idle screw is located just above the idle jet (Use the above image for reference)

The function of the idle screw: The idle screw will determine how much the throttle closes in idle conditions. If you turn in the idle screw it will prevent complete closing of the throttle when the engine is idling and therefore increase the idle speed.

Similarly, if you loosen the screw, the throttle will close completely in idle condition and decrease the idle speed.

Adjusting the idle screw: If you want the engine to have higher rpm while idling, you’ll need to tighten the screw so that the throttle doesn’t close completely on idle and vice-versa if you want lower rpm then loosen the screw.

Air-Fuel mixture screw

Refer to the image above for the location.

Function: The air-fuel mixture screw is going to control the amount of air that enters the engine. If you tighten the screw it will make the mixture rich and if you loosen the screw, the mixture will be lean.

Adjusting the Air-Fuel Ratio: Before we discuss any adjustments, the important thing to note is that most of the new Predator 212’s stock carbs are non-adjustable, this is due to government regulations to protect the environment.

If your air-fuel mixture screw is fixed, then you’ll need to either clean your carburetor or change your idle and main jet to fix your carburetor issues. Unfortunately, you can’t just make a quick adjustment.

The other option is to get a new adjustable carburetor, they only cost 10-15. You can check our choice of best carburetors for Predator 212.

But if you do have an adjustable screw, then you can tighten the screw for a richer mix and loosen the screw for a leaner mixture.

• Keep your engine running.
• First adjust the idle screw to an idle speed of your liking.
• Observe the sound the engine is making. If your mixture is too rich, the engine will sputter and if the mix is too lean the engine will produce bogging sound.
• Tighten the air-fuel screw if the engine is bogging and loosen the screw when the engine is sputtering. Find the balance.

Mikuni Carburetor Adjustment

Mikuni VM22 and its clones are the popular carb upgrade for go-karts and mini bikes, they are not as simple a design as the stock carburetors.

Note: Most of the Chikuni/Mikuni carbs come with a #98 main jet which isn’t big enough if you have a stage 1 air filter installed, the engine will run lean. In such cases, you need to first get a bigger jet (at least #120), adjustment alone won’t fix your issue.

Use this image as a reference for screws in the VM22 Mikuni.

• Take your screwdriven and turn the Air/fuel screw all the way in but not too tight.
• Now loosen the air/fuel screw to 1 and 1/2 turns out
• Start your engine
• Once the engine starts running, tighten or loosen the screw 1/4 turn at a time and take note of the rpm. You need to find the position at which the idle rpm is maximum.
• Keep making 1/4 turns untill you find the maximum rpm.
• Once you find the highest idle rpm position, loosen the idle screw.

If the throttle responsiveness isn’t good then it’s usually due to lean mixture, you’ll need to adjust the needle in such a situation, check this article to understand how the Mikuni works and how to adjust the needle valves.

What to do if your Carburetor doesn’t have an Adjustable air-Fuel Screw

Most of your carburetor issues can be solved by cleaning the main jet and the pilot jet. If the engine isn’t starting or it’s starting but dies out at half or full throttle, you will need to take your carb apart and clean all the components.

Sometimes, bad fuel can also cause these issues so make sure to check your fuel tank.

Basically, having an adjustable screw allows for a quick fix, so not having one will require more work.

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.

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

Key Specs

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.

Toro Recycler 60-Volt Max Lithium-Ion

Key Specs

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

Key Specs

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 M220

Key Specs

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

Key Specs

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.

QA

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.