Small lawn mower engines. Best Lawn mower Engines

Best Lawn mower Engines

Buying the best lawn mower engines is, without a doubt, a daunting task. The wide variety of lawn mower makers in the market might overwhelm you as everyone claims to make the best lawnmower engines. Whether you want the best reel mower for Bermuda or trim your Centipede grass, you need a lawn mower with the most efficient and powerful engine.

Honda HRX217VKA, in this regard, is the best option when it comes to choosing the best lawn mower engines. With its powerful and sturdy engine, you can rely on its performance and keep your lawn in perfect condition.

While Honda HRX217VKA makes the best choice for your lawn mower engine, you must know the other options to pick the one that fits the needs of your lawn, and this product is usually out of stock. The article addresses all your questions regarding the best lawnmower engines and the factors you should consider when buying them.

What Makes the Best Lawnmower Engine

Reliability

You might have never considered reliability a significant factor when buying a lawn mower. However, it is one of the most important factors and can make a huge difference. Whether you or your gardener uses a lawnmower frequently or sparsely, you must consider the reliability of your lawn mower’s engine.

Keep in mind that all reputed brands of lawnmowers assure reliability. It is because the longer lifespan of your lawn mower’s engine depends on its quality. We recommend you steer clear of inexpensive or unbranded engines when choosing the best lawn mower engine.

Efficiency

Indeed, efficiency is the MOST important factor. It plays a huge role in the overall performance of the lawnmower. But it is worth mentioning that the efficacy of your lawn mower depends on multiple factors. From engine power, fuel efficiency to the availability of parts, you need to consider everything.

In general, the lawn mower engine usually comes in the range of 150cc to 190cc. Making the right choice for the powerful engine is typically a matter of knowledge. Buying engines with more CCS translates into investing in a powerful machine. It further depends on the type of work you do on your lawn.

That is to say, if you’re planning to trim extra long grass in your yard, your lawnmower needs a powerful engine. However, if you’re looking just to trim a shaped and well-maintained yard, choose the one with lower power.

Lawn mower engines such as Honda or Briggs and Stratton are utterly long-lasting and durable. The engines offer both reliability and power at reasonable costs.

Maintenance

Note that the longevity of your lawnmower engine highly depends on its maintenance routine.

From cleaning the waste to changing the air filter and oil, everything comes in the maintenance routine. Manufactures design commercial engines to function for long-lasting hours. However, you need to put more effort into maintaining a consumer engine to make it durable for years.

Best Lawn mower Engines You Can Buy

Honda HRX217VKA 21

The Honda is the self-propelled and powerful machine you can buy for an all-rounder performance. The robust lawn mower engine comes with a slew of excellent features, making it a high-end model. It is the best lawnmower powered by gas.

In fact, it has received the highest rating from the existing users. It is the hefty 200CC Honda motor is that makes it the most powerful lawn mower engine.

Secondly, the engine comes with a ‘Select Drive’ characteristic. The feature allows you to manage the speed of the motor.

Editor’s choice: The Best Lawn mower Engine

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That means with this lawnmower engine you can easily cut the grass at your chosen pace. It doesn’t make you feel dragged behind the mower.

Some advanced features include the exclusive 21 in NeXite deck, the 4-in-1 Versamow System, and Micro-Cut Twin Blade System. They allow you to bag, mulch, and rear discharge leaves without using any tools.

over, the Honda HRX217 lawnmower engine offers coverage for five years. With this engine, you can rest assured that the company will deal with it if any issue arises. The powerful NEW GCV200 lawn mower engine provides reliable power for a long time.

Honda lawnmower engine is certified to meet CARB emission levels and 50-State EPA. Hydrostatic Cruise Control provides precise control of speed that is adjustable and manageable from 0 – 4 MPH.

Briggs and Stratton 31R907-0007-G1

Briggs and Stratton is another credible name in lawn mower engines and related products for years. It has been delivering premium-quality products at affordable prices.

The lawnmower of this company is an excellent example of superior service and commitment.

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In addition to offering commitment, the lawn mower engines offer 500cc power with its single-cylinder machine.

The engine has a high-quality dual clean system to provide quick air filtration. It uses an electric starter that makes it easier to work without having to invest a lot of time or effort.

Note that it is one of the few lawnmower engines that have Magnetron electronic ignition. As the ignition is maintenance-free, the engine is an ideal choice for mowing small lawns with ease. This lawn mower engine comes with the Dura-Bore cast iron sleeve with the cylinder to ensure longevity.

Furthermore, it has a pre-installed muffler and 9AMP system for charging the battery. There are no denying lawnmower engines from Briggs and Stratton offer you supreme quality. The engines are highly trustable as they are CARB compliant.

The engine gives you a smooth performance with its linear balancing system. Many experts believe that the engine performs consistently and effortlessly without giving users any trouble.

Kawasaki FJ180V-BM09 Engine

Kawasaki is a fabulous company in the lawn mower engine industry. The company makes lawnmower engines that offer powerful performance.

The lawnmower engine is a commercial replacement that you can buy for less than 400 to 500 dollars.

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If you‘re looking for your FJ180V-BM09 replacement, this Kawasaki FJ180V-BN09 can be the right choice. The model is not only ideal for all the commercial push mowers but also consumer ones. All you need is to transfer the gas tank, the fuel line, and the choke lever from the original engine.

Kohler – KT715-3047 7000 Series

Kohler 7000 Series lawn mower engine is a high-power that can work as a replacement for your riding mowers and all residential zero turns.

The 725cc engine has an amazingly high-power rating of more than 20 HP.

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Besides this, the high-quality engine has an expert Performance filtration system. The powerful system enhances air, oil, and fuel filtration. It comes with pressure lubrication that keeps all the critical components well-lubricated in the engine.

This Kohler’s lawnmower engine makes the perfect choice for freezing areas. We say this because it can even start at a temperature that is below freezing. The Smart lawn mower engine uses the Smart-Choke technology that enables the engine to kick start at all throttle positions.

So, there is no need to worry about the choking engine. The consistent cut technology of this lawnmower engine maintains the speed of the engine.

Final Verdict

Finding the right replacement for your lawn mower engine is tricky. Many factors are important to take into account before you make this decision. Among all the options mentioned above, the Honda lawnmower engine has a reputation as the most fuel-efficient machine. It gleans the great power from the fuel and is low on emission that damages the environment.

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

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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.

Lawn Mower Engine Surging – Check this easy fix first!

Lawnmower engine surging is a right pain in the Jacksie; it’s an engine that runs erratically and revs up and down by itself uncontrollably. In some cases, it may only happen under certain conditions, for example, only after the mower gets hot or only when the fuel level gets low.

So what causes the lawnmower engines to surge? The most common reason for a surging lawn mower engine is a blockage in the fuel supply, but there are other possibilities:

Often you’ll find playing around with the throttle helps or applying some choke. You are not on your own; this is a regular complaint. In this guide, we will cover the diagnosis, likely causes, and solutions.

Try the easy fix first – replacing/cleaning gapping the spark plug before attempting carburetor work. If your mower engine is a Honda or Kohler, the fix is simple. Honda and Kohler’s surging is commonly caused by a blocked idle jet see “Gas starvation” towards the end of the page.

If you need more help, check out the “How to fix a surging mower video.”

If your surging mower is a Honda, check out the “Honda mower surging video.”

For many mowers, the fix is to replace the carburetor, and as carburetors are inexpensive, it just makes sense to swap it out and save a ton of messing around. You can check out the quality carburetors available and conveniently delivered to your door by Amazon.com.

Need more info on the fuel system, carburetor components, and how they work, you can check them out here.

Briggs Stratton Surging

Surging BS Classic 450, 500, or 550Some engine types are famous for surging; the Briggs Stratton 450, 500, and 550 series engines are fitted with a metal fuel tank and priming bulb-style carburetor. If you have one of these types of engines and it’s surging – You’re in the right place.

If you don’t have this type of carburetor, skip this section and jump to “Surging Test” below. These engines are fitted with a metal fuel tank and carburetor combination. The gasket sandwiched between the tank, and carburetor distorts over time, allowing a vacuum leak.

The vacuum leak causes the surging; replacing the gaskets and cleaning the carburetor/tank will leave it like new, I promise. In this tutorial, we’ll remove the tank/carburetor unit, clean it and replace the gaskets. Just some basic tools are needed, but get yourself a can of carburetor cleaner; it makes the job a lot easier.

In the workshop, I use WD40 carb cleaner, and you can check out all the tools and parts I use here on the “Small engine repair tools” page.

Tools You’ll Need

Here’s a short list of tools you’ll find useful to complete the task of fixing your surging mower. These tools aren’t essential, but they do make the whole job a ton easier; you’ll need:

Fuel treatment – Every small engine owner should use gas treatment. Most people don’t know gas goes off, and gas left in small engines can cause real problems, as you already know.

Using a gas stabilizer will keep the gas in your mower and your gas can fresh for up to two years.

Carburetor gasket – If you’re fixing the BS Classic engine, then you’ll need this gasket set.

Complete carburetor – As an alternative to replacing your BS Classic carburetor gasket, replace the complete carburetor instead; it includes the replacement gasket.

Manifold – This will only be needed if you have confirmed it has failed. Note there are a few different types of manifold pipe, so be sure to check before ordering.

You can check out all these tools on this page “Carburetor Surging Repair Tools.”

This carburetor style is fitted to a few engines and is prone to gasket failure. The job of replacing is simple and will solve the surge. The process is as follows:

Remove the spark plug wire – prevents the mower from starting.

Remove – Remove and clean the air filter and filter housing – Clean it using soapy water, and when dry, smear some engine oil over the surface of the foam. This helps trap dirt.

Remove tank bolts – They hold the fuel tank to the engine.

With fuel tank bolts removed – pull the tank unit straight out gently and remove the governor control link.

Remove the black rubber elbow crankcase breather pipe. Remove the manifold seal and keeper ring. Sometimes they will come loose and get stuck on the manifold pipe.

Remove – Remove carb screws from the carburetor and set aside.

Using a can of carburetor cleaner – clean all the ports on the surface of the fuel tank.

Empty the tank and rinse it out with fresh gas.

Pull the Siphon from the carburetor; they can be stubborn. Remove both gaskets and use carburetor cleaner to clean the siphon metal filter and all ports of the carburetor. Check the primer bulb for damage; mice like to eat them.

Spray – Spray the carburetor with carb cleaner.

Remove – Remove old gaskets and discard them.

Careful of this spring; it lives under the gaskets, and it can drop off and be tricky to find, as I know only too well.

The gasket is a two-part kit; the rubber-type gasket faces the tank. (carb fitted here for demo only)

The Siphon pushes back into the carb with a click. If you don’t hear the click, it’s not right – try again.

Refit the carburetor to the tank. Don’t over-tighten the screws, as this will distort the gasket. Fit manifold seal and keeper. Smear a small amount of oil on the seal; it helps it seat.

Clean the intake manifold. The grey tube in this shot is manifold. Inspect it for any signs of damage; they are prone to cracking. This will also cause a surge.

To fully inspect the pipe, you need to remove the pull assembly.

I would only do this if there was obvious damage to the manifold or if I had replaced the carburetor gasket and the engine was still surging.

This manifold is cracked and will cause a surge.

Before refitting the tank, fit the keeper ring and O-ring seal. Lube the seal before refitting the gas tank.

Offer the carb/tank unit up to the manifold and attach the governor link and spring. Now push the unit firmly onto the manifold. Fit both bolts.

Refit the air filter and spark plug wire. Use only fresh gas; make sure your gas can is clean. Gas older than three months is stale.

If, after fitting the gaskets, you still have a surge – Replace the Manifold.

Surging Test

As you know, gas starvation causes an inconsistent flow of fuel which in turn causes erratic running. And you also know a vacuum leak will cause erratic running, but it is a much less common cause; however, some carburetors are prone to vacuum leaks.

As engine manufacturers strive to make their engines more efficient, they have also made the carburetors more likely to clog; this has become a common issue.

To quickly diagnose which problem you have, a clogged carb or vacuum leak, follow this simple test.

You will need a helper to hold the bail lever or improvise with duct tape. CAUTION careful where you place your fingers and toes; the engine will be running, so the blade will be spinning.

Your mower will have a Manual choke, Auto choke, or a Primer bulb. Identify which type your mower has; the test is slightly different for each.

If you have a manual choke – apply half choke with the engine running.

If the engine now runs without surging – Gas starvation is the likely fault. If it runs just the same – A vacuum leak is a more likely fault.

If you have an Auto choke – Remove the air filter cover and filter – place a clean rag over the intake while the engine is running.

If the engine now runs without surging – Gas starvation is the likely fault.

If the engine runs just the same – A vacuum leak is the more likely fault.

If you have a primer bulb – you can still do the test – while the engine’s running (need a helper); give it some extra gas by pressing the bulb.

If the engine now runs without surging – Gas starvation is the likely fault.

If it runs just the same – A vacuum leak is a more likely fault.

Gas Starvation

If the test revealed gas starvation, it also showed that your problem is likely a dirty fuel jet in the carburetor, or the gas may be stale or contaminated by water.

Cleaning the main jet usually does the job.

Idle Jet Surging – Honda and Kohler use a relatively easy-to-access idle jet that clogs up and causes surging. The Kohler is easier to access than the Honda.

The Kohler is easier to access than the Honda.

Briggs has fitted a plastic carburetor to a range of engines which also clog up and cause surging.

All of these carburetors can be repaired by cleaning, which I’ve covered previously in videos (links below). Videos cover step-by-step removal, cleaning, refitting, and adjusting your carb.

Fixing this is not difficult. Sometimes you can get lucky by just draining and cleaning the gas bowl, which only takes a few minutes.

I have written a complete guide to Carburetor cleaning with pictures; it includes the gas bowl clean-out, which, as said, is worth trying first.

If cleaning doesn’t work out for you, go ahead and swap out the carburetor for a new one. Check out “New lawn mower carburetors page,” here, I’ve listed good quality replacement carburetors for all the most popular engines.

Carburetors aren’t expensive; messing around with them doesn’t make sense.

You might find this page helpful too – “Carburetor repair tools” I’ve listed some really useful tools that make the job easy. Some of these tools I’ll bet you already have some.

But do try cleaning the gas bowl before removing the carburetor.

Finding a Vacuum Leak

Air that enters the combustion chamber without passing through the carburetor is un-metered. This means the fuel-to-air ratio is unbalanced and, in turn, causes erratic engine performance.

When air sneaks in like this, it causes the engine to run lean (lacks gas). A lean engine runs hot, which isn’t good for an engine, especially an air-cooled one.

Vacuum leaks usually occur because of damaged gaskets. Gaskets are sealing materials fitted between the mating surfaces of engine components. Their function is to create an airtight seal.

They are commonly made from paper, felt, cork, Teflon, neoprene, metal, and rubber. The material type is dependent upon where the gasket is to be used.

Gaskets wear out and break down, and that causes surging.

Extreme Caution – You need to be careful, the engine will need to be running, and so the blade will be spinning when running this test.

A vacuum leak check is performed with the engine running and a can of carburetor cleaner; WD40 works, too, (is there anything WD can’t do?)

Spray the cleaner around all carburetor gaskets anywhere the carburetor meets the engine. The trick is to hear an instant change in engine note; that’s the sign of a vacuum leak.

This can be challenging; you must train your ear to notice the instant change in engine note (and not the surging).

Just do a small section at a time; this will allow you to pinpoint the failure area. Jumping the gun and replacing gaskets without finding the actual leak may work out for you or leave you with the same problem after the rebuild.

You’re right in thinking carburetor gaskets usually cause the problem, but other components, such as manifold pipes, can crack or become loose, causing surging.

Fixing A Vacuum Leak

If a leak is detected, replace all carburetor gaskets, and as you have the carburetor removed, go ahead and clean it. Replacement gaskets are available online; you will require the make and model numbers from the engine.

All manufacturers will have a model number printed on a sticker placed on the body or on the engine. Have a poke around; you’ll find it. Most engine manufacturers will stamp the model numbers in an accessible area. Briggs Stratton stamp their numbers on the metal engine cover.

A new carburetor comes with new inlet gaskets; I like to fit original parts where I can; they fit and are guaranteed.

If, after replacing the carburetor gaskets, the engine still surges, you’ll need to go a little further and replace the manifold intake and gasket.

It’s not a big job, and they don’t give a lot of trouble, but they do crack as they get older. I wrote a step-by-step guide showing you everything you need to know – “Briggs Manifold Replacing.”

Related Question

Honda lawn mower surging fix? To fix a surging Honda lawn mower engine, clean the carburetor, gas tank, and fuel filter. Use fresh regular gas or e10. What causes a lawnmower to run slowly? The most likely cause is a throttle linkage bent out of shape by bumping into the shrubbery or a throttle spring has detached itself.

Hey, I’m John, and I’m a Red Seal Qualified Service Technician with over twenty-five years experience.

I’ve worked on all types of mechanical equipment, from cars to grass machinery, and this site is where I share fluff-free hacks, tips, and insider know-how.

And the best part. it’s free!

Proper maintenance for your mower is key to a working machine and a healthier lawn—and it all starts with the right refill. Get to know your lawn mower engine oil options here.

By Amy Lynch and Bob Vila | Updated May 27, 2021 10:13 AM

We may earn revenue from the products available on this page and participate in affiliate programs.

Q: I haven’t changed my lawn mower’s oil since last season, so I’m feeling rusty. Remind me: What type of oil can I use in my lawn mower?

A: You’re not alone. In fact, this bit of lawn mower maintenance happens so occasionally that some people forget to replenish lawn mower oil in the first place. It needs replacing after every 20 to 50 hours of operation, depending on your mower’s specifications. If your yard is small, that might mean as few times as once a year! But, while this task is infrequent, it’s also important to change the oil properly—starting with the correct type of oil for lawn mowers—to keep your machine running.

Two types of oil can go into operating lawn mowers, but your mower’s size, type, and capacity might help determine which of these two is the better option. Even the climate you live in can make a difference when the time comes to change or add oil, since each type of oil for lawn mowers has its own recommended temperature range. If you live in a place that frequently heats up to more than 100 degrees, for example, it might be wise to choose an oil made to withstand a wide range of temperatures.

Different Kinds of Lawn Mower Engine Oil

According to a survey of consumers conducted by Briggs Stratton, the world’s largest producer of gasoline engines for outdoor power equipment, 48 percent of those who buy automotive oil for their mower believe that automotive oil and small engine oil are one and the same.

In fact, lawn mower engine oil (as well as oil for other small engines) might actually be the only type your mower can tolerate. Using motor oil meant for a tractor or car can clog and disable some units completely due to its higher viscosity.

Always check your manufacturer’s specifications first. No owner’s manual handy? If yours has a Briggs Stratton engine, you can use the company’s interactive tool to determine the best oil for your specific lawn mower’s engine based on its make and model, motor type, and local climate. Talk about a shortcut! Otherwise, at a minimum, it’s important to keep a few guidelines in mind.

Lawn Mower Oil Types

Not all oils are equal, and it helps to get to know the subtle differences to determine the best oil for a lawn mower and avoid a costly mistake. In general, there are two main types of oil: motor oil and small-engine oil. Brands vary in their formulas, with some being regular oil, some a mix of regular and synthetic and some fully synthetic. Older oils typically were one weight or grade only, but newer oils have a viscosity rating added.

• SAE 30 is a single-grade, or straight weight, oil with a viscosity rating of 30 and is safe for small, air-cooled engines, typically older models.
• SAE 10W-30 is a multigrade engine oil that can work in cold temperatures, as well as hot, for a fairly balanced temperature range.
• SAE 5W-30 is a multigrade engine oil with a low viscosity to flow better at colder temperatures (than 10W-30), but protect the engine enough in heat.
• Synthetic SAE 5W-30 is a synthetic (artificial) lawn mower oil that works for both cold and warm weather. Synthetic oils tend to be more stable across temperature ranges than conventional oils.
• Vanguard 15W-50 is a brand of fully synthetic engine oil designed for commercial applications that operates at temperatures ranging from 20 to 130 degrees.

VISIT TO BIG BUCK MOWERS / KOHLER AND KAWASAKI ENGINE TEAR DOWN / WHY DID THEY FAIL?

Motor Oil SAE Viscosity Grade

The Society of Automotive Engineers (SAE) grades motor oils by viscosity. Viscosity loosely relates to weight, or thickness, and more accurately as a measure of how the oil flows at specific temperatures. In colder temperatures, thinner single-grade oil performs better in engines.

BEST LAWN MOWER ENGINES

It gets a little more complicated with multigrade engine oil. Look at the first number, with a W (10W, for example) as a measure of flow in cold temperatures. The W stands for winter (not weight). The lower this number, the less viscosity an oil will have at colder temperatures, and the better it will flow. Too thick when the engine starts, and it won’t flow through and protect those critical engine components.

The higher number that follows (the 30 in 10W 30) refers to viscosity at higher operating temperatures and in hot weather. Multigrade oils typically are designed to flow in a range of temperatures to match conditions. Some oils have additives that also keep viscosity steadier in cold or heat.

How to Choose the Best Oil for Your Lawn Mower Engine

When choosing the right lawn mower oil type for your mower, your best bet is to check the manufacturer recommendations. Also consider the engine type (such as 2-stroke engine), oil viscosity, and average temperatures where you live.

Motor Oil for Four-Stroke Engines

Four-stroke engines tend to power heavy-duty equipment, but are reliable and your best bet for larger lawns. These engines are common in large and/or riding lawn mowers as well as some push mowers. Even so, be sure to check your manufacturer’s manual or website for specific instructions on which grade of motor oil to use, since—much like a car—the engine might be sensitive to certain additives.

Oil and gas are kept separate in a four-stroke engine. Oil with a grade of SAE-30 is often a safe bet, but it’s still worth confirming since a lawn mower is no small investment. You can buy SAE-30 motor oil online (view example on Amazon), at any auto parts store, from most gas stations, and in the automotive section of a hardware store.

Small Engine Oil for Two-Stroke Engines

This type of engine is most commonly found in smaller and older push mowers, plus other small engines, like on weed trimmers and chainsaws. Its popularity as a preferred lawn mower engine has decreased some over the years as four-stroke units have become more common. Louder and smokier than their four-stroke counterparts, two-stroke motors can keep running no matter how steep an angle you’re trying to tackle (think: hilly or sloped terrains).

Two-stroke engines are lighter and cost less, too. And, since they use the same fill port for both gasoline and small engine oil, two-cycle motors require owners to mix them together in a specific ratio such as 32:1 or 50:1—refer to your operator’s manual for the correct gas-to-oil ratio.

These oils typically have additives to help clear carbon deposit and minimize wear, among other tasks. Find small engine oil online (view example on Amazon) or in the lawn and garden section of any hardware or auto parts store.

Know when to change your lawn mower’s oil.

A brand new mower might need an oil change after the first 5 hours of use; refer to your unit’s manual. Beyond that, small motors might need an oil change every 25 hours of use or thereabout, while larger motors typically can last up to 50 hours before requiring oil replacement.

A handful of factors can increase the frequency of oil changes, including extreme dust and dirt, rough terrain, frequent mowing of wet or muddy grass, and even a hot climate—conditions in which the engine is forced to work harder. If you have a large yard (or if you mow a small yard frequently), use a dipstick or clean cloth to check the lawn mower engine oil level before each use once it’s run beyond 20 hours or so.

Even if the mower hasn’t hit the 20-hour mark at the end of a season, make a point of changing your oil each spring, before your first mow. Avoid overfilling the mower by checking the oil level with a dipstick.

FAQ About Lawn Mower Oil

What kind of oil do you use in a lawn mower?

The oil type depends on the engine type, typical operating temperatures, and especially the recommendations of the lawn mower manufacturer. In general, small-engine oil that is a mix of oil and fuel works in two-stroke engines, and straight oil typically works for four-stroke engines. Factors such as temperature affect which grade to choose.

Can you use regular motor oil in a lawn mower?

Lawn mowers with four-stroke engines might do fine with regular motor oil, but always check the manufacturer documentation to make sure. Some automotive oils are too high in viscosity and meant for larger engines, so don’t assume that more is better. Many deluxe models of push mowers and riding mowers use regular motor oil. Two-stroke engines cannot use motor oil; they need a mix of fuel and oil specially designed for small engines.

What’s the best oil to use in a lawn mower?

The best oil to use in a lawn mower is the one recommended by the manufacturer. Viscosity and whether the oil is synthetic or regular oil can vary based on climate, conditions, and engine type.

Can I use 10W30 instead of SAE 30 in my lawn mower?

No, it is not recommended. Most engines that call for SAE 30 are older models of mowers with engines designed for straight weight oil. These models were designed before multigrade oil became available, so you should not substitute with the multigrade option.

Final Thoughts

Lawn mower oil is essential to keeping your mower running efficiently and effectively, and use of the right oil, plus regular oil changes, can protect the life of the mower’s engine. Take the time to find out the best oil for your lawn mower based on the mower’s model and recommendations of the manufacturer. Also consider operating conditions, viscosity, and type of engine.

A little prep avoids irreversible damage caused by forcing the wrong oil through your lawn mower’s engine.