Are Lawn Mower Spark Plugs Universal. Spark plug for mower
Are Lawn Mower Spark Plugs Universal?
Lawn mowers are surprisingly complex machines with quite a few moving parts, any of which could break. Generally speaking, lawn mowers come in two varieties; walk-behind mowers and lawn tractors with a mower blade underneath. There are several small engine manufacturers that build the engines that are found in either of these machines, and where there’s different engines, there’s different parts for those engines. Are lawn mower spark plugs universal? Lawn mower spark plugs are not universal. Each engine model has a specific spark plug that will fit it, and swapping out the incorrect spark plug could cause engine failures or damage. Before installing a spark plug, you should ensure it is the right model for your particular engine. The spark plug is part of the ignition system, which creates the spark of electricity that ignites the air and fuel mixture in the engine. Replacing the spark plug on a lawn mower is a relatively simple process but ensuring you use the correct spark plug for your engine model is critical to keeping your mower running smoothly. Keep reading to find out all about lawn mower spark plugs and how to replace them.
Are Lawn Mower Spark Plugs Universal?
While specific spark plug models are not universal, all working engines require a spark plug. There are several large manufacturers of lawn mower engines, which are typically a different manufacturer than the lawn mower (for example, Briggs Stratton supplies the lawn mower engines for Husqvarna brand mowers). Each of these manufacturers have a different spark plug, and even some different engines by the same manufacturer have different spark plugs as well. You should always check with the manufacturer or your owner’s manual to find spark plugs that are compatible with your mower.
How Are Spark Plugs Different?
A spark plug is a component of an engine’s ignition system. In combustible engines, the spark plug provides the small electrical spark that ignites the air and fuel mixture in the pistons, which then creates an explosion that causes the pistons to start pumping, thereby starting the engine. Because the spark plug is involved in a mini-explosion every time you start the engine, it needs to be made from durable materials. Spark plugs are differentiated by their thread width, the gap they’re designed for, and their heat rating, among other things. The importance of making sure you have the right spark plug for your lawn mower model cannot be overstated. If you buy a replacement and it doesn’t go in properly, don’t force it, as you may damage the threads in your mower. Without a properly fitting spark plug, you could damage your small engine and void the warranty as well.
How Do You Know Your Spark Plug Needs to Be Replaced?
If any of these happen with your lawn mower, one of the first and simplest things to check is your spark plug. Do a visual inspection of the plug, checking to see if there’s any excessive dirt or debris on it, if the electrode is damaged, or if the porcelain portion is cracked. If you can’t clean your spark plug or if one of the parts is damaged, it’s time to replace the plug.
However, your spark plug may just be dirty and covered with engine dirt and grime. You can remove the spark plug, following the steps outlined in the owner’s manual for your mower, and clean it with a spark plug cleaning brush or rag.
Spark plugs aren’t expensive, and they’re designed to last for years. Most lawn mower manufacturers recommend that, as part of your yearly maintenance on your machine, you check your spark plugs for serviceability.
How to Find the Right Spark Plug for Your Lawn mower
The spark plug you purchase should be the recommended plug for your lawn mower. The simplest way to make sure you buy the same plug is to take the old spark plug to your local hardware or auto store and buy the identical part. Your owner’s manual or the manufacturer’s website will be a good source of information as well, telling you exactly what sort of spark plug you need to fix your mower.
Spark plugs are made from a variety of different metals and materials, each of which has differing levels of durability. Copper spark plugs are the cheapest but also last the shortest amount of time, while spark plugs made from platinum or iridium are more durable and will last much longer.
Of course, the more durable the material, the more expensive the spark plug. A copper spark plug will usually be just fine for a lawn mower, and if you check it at least annually as part of your lawn mower maintenance, it’s quite possible that it lasts as long as the life of your lawn mower.
Walk-Behind Lawn Mowers
Walk-behind mowers have small engines that either come in a two-stroke or four-stroke variety. For these small engines, you’ll likely be using an L-head or side-valve spark plugs because the engines are called either L-head or side-valve engines.
These spark plugs may be smaller or made from different types of materials than automotive spark plugs, but it’s possible you can find the same spark plug in an automotive store. Your engine’s manufacturer can give you a list of suitable replacement spark plugs.
Lawn Tractor Spark Plugs
Lawn tractors are powered by much larger engines than walk-behind lawn mowers, being more similar to car engines (albeit on a much smaller scale). These engines, which are referred to as overhead valve engines because of their design, can range from 13 to 30 horsepower, though the larger, commercial use lawn tractors can have even higher horsepower ratings.
These engines will usually need a more durable spark plug than a small walk-behind mower, and you might have better luck finding a suitable replacement at an auto parts store.
Where Can You Buy Replacement Spark Plugs?
Replacement spark plugs are easy to find. As long as you have the part number your engine requires, you can visit most automobile parts stores or your local hardware store. The hardware store where you purchased your lawn mower is very likely to have the specific spark plugs designed for your engine model.
You can also have great luck finding replacement spark plugs on your engine manufacturer’s website. Usually, the manufacturer will let you look up your engine by model number, then will have links to be able to purchase suitable replacements.
There might be several plugs that will fit your mower, in which case you might choose according to customer reviews or cost. A spark plug for your push mower will probably cost you around 5.
Final Thoughts
Lawn mower spark plugs are designed for a specific engine, and different engine manufacturers require different size or spec spark plugs. If you have a lawn tractor, your engine is different as well and therefore requires different spark plugs. Spark plugs are built to withstand high amounts of heat and pressure, but they can become caked with engine debris or damaged after many uses.
If you need to replace a spark plug, your best bet is to check with the manufacturer of your lawn mower engine and buy the recommended part number. That way, you can keep your lawn mower starting smoothly and running well for years.
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How to Tell When it Is Time to Change Bad Spark Plug in a Lawnmower
A lawnmowers spark plug plays a critical role in how the engine operates. If it fails to fire, or doesn’t work properly, your lawnmower will not work.
But how to tell if a lawn mower spark plug is bad?
There are a few ways to diagnose a bad spark plug. The following article will explore Symptoms Of bad lawn mower spark plug, and When How To change a spark plug in a lawn mower.
- 1 What Does A Sparkplug Do?
- 2 What Are Some Signs Of A Bad Spark plug?
- 3 how to tell if a lawn mower spark plug is bad?
- 4 how to change a spark plug in a lawn mower?
- 4.1 Step 1: Disconnect the lawnmower’s sparkplug wire.
- 4.2 Step 2: Use the spark plug socket to carefully remove the spark plug.
- 4.3 Step 3: Examine the sparkplug, paying close attention to the electrode.
- 4.4 Step 4: Double-check the new sparkplug.
- 4.5 Step 5: Install new spark plug
- 6.1 Can Dust And Debris In The Fuel Tank Cause A Problem?
- 6.2 Cleaning Or Replacing the Air Filter
- 6.3 Winter Lawnmower Maintenance Helps Preserve The Engine And Spark Plug
- 6.4 Stabilize the Fuel
- 6.5 Clean the Deck
- 6.6 Spring Lawnmower Preparation Is Essential
- 6.7 Change The Oil
- 6.8 Lubricate the Moving Parts
What Does A Sparkplug Do?
It’s essentially an electrical device that directly draws power from a special induction coil that is connected to the flywheel of the engine.
When it is operating properly it ignites the fuel and air mixture in the combustion chamber. Without it, there is no way to burn the fuel and the piston that drives the mower’s blades simply will not work.
While spark plugs are designed to be durable, and their construction is quite simple, they do have a finite lifespan.
As they start to degrade, or physically deform from excessive use, the spark plug tends to fire intermittently.
What Are Some Signs Of A Bad Spark plug?
As time goes on a failing spark plug could make it much harder to start. This could manifest as a frustrating number of pulls on the drawcord.
In the case of a riding lawnmower, it could take a lot longer for the starter motor to turn the engine over, which could also start to tax it or even affect the life of the battery.
Wrong Spark plug Effects Coil Like this (LAWN MOWER Ignition Coil)
A badly degraded or deformed spark plug could cause the lawnmower’s engine to stall. This is especially likely to happen if it bogs down in tall grass.
A riding lawnmower with a hydrostatic transmission and a bad spark plug could potentially stall out completely when the engine is being taxed by doing something like cutting while going uphill.
how to tell if a lawn mower spark plug is bad?
If you are paying attention, you can usually notice if a lawnmower’s sparkplug is starting to go bad.
A pull mower might take an increasingly longer number of pulls, or a riding mower might take longer than usual to start when you turn the key.
A lawnmower with a bad sparkplug might also start to develop performance issues or consume more fuel than usual. This could even cause a lingering smell of raw gasoline while you are mowing.
A truly bad sparkplug might also show visible signs. Physically the center of the electrode should have a flat top. If you take the plug out and it looks rounded on top or there are some cracks, then it’s probably wise to replace it.
At the same time, some bad spark plugs will also look black from carbon or degraded excess gasoline.
In a pinch, you might be able to lightly clean the plug and gently adjust the gap between the electrodes.
While this might work once or twice, to get you through a mowing session, you should still consider replacing the plug.
how to change a spark plug in a lawn mower?
Spark plugs have a limited lifespan. So, it’s unrealistic to expect it to last forever.
However, making sure that you properly maintain the lawnmower’s engine and other components can reduce the conditions that can prematurely shorten the spark plug’s lifespan.
It’s also worth bearing in mind that seasonal maintenance is just as important as periodic in-season maintenance.
Beware Dust And Debris
Dusty, dry conditions can potentially affect how a lawnmower performs. Dust and even excessive airborne pollen can start to clog the air filter.
When this happens the fuel-air ratio in the engine’s combustion chamber can lead to premature carbon buildup in the carburetor or around the spark plug.
Can Dust And Debris In The Fuel Tank Cause A Problem?
At the same time dust that gets into the fuel tank through the breather on the gas cap or when you open the cap to refill the tank can become a problem.
As it settles lower into the tank these tiny particles can start to collect and congeal. If you run the tank low or completely dry during a long mowing session, this debris can be sucked into the fuel line.
Not only can this impede the passage of fuel into the system, but it can also start to clog the lawnmower’s fuel filter.
Cleaning Or Replacing the Air Filter
Air filters naturally clog over time. In a certain light, it’s their job. When it is functioning properly, the air filter is tasked with catching any dust and airborne debris before it makes it into the carburetor.
As debris starts to buildup, it can rob the lawnmower of the air it needs to efficiently ignite the fuel-air mixture in the engine’s combustion chamber.
Excess fuel and other debris can then damage or corrode the spark plug.
With some older, gas-powered trimmers and lawnmowers, the air filter is little more than a piece of soft flexible foam.
To clean it you simply loosen the long, threaded bolt that holds the lid in place. You can then wipe off any noticeable debris with a clean piece of paper towel or a shop rag.
If you have a can of air or a shop air compressor, you might be able to blow off any stuck-on debris.
Some newer gas-powered push mowers and riding lawnmowers have more sophisticated air filters and air cleaner systems.
In a case like this, you should check the part number in the owner’s manual. If you don’t have it, the air filter itself might have something stamped or printed on it.
When in doubt, you should be able to easily take it out and bring it with you to the auto parts store.
There are even some discount retail chains that have an automotive department stocked with common lawn mower air filters.
Winter Lawnmower Maintenance Helps Preserve The Engine And Spark Plug
If you live in a part of the country where it gets cold in the winter, or the grass merely goes dormant, then you will need to take some measures to ensure the lawnmower is stored away properly.
Stabilize the Fuel
Fuel stabilizer is very important when storing a lawnmower for the winter. Not only does it help prevent the octane of the gasoline from degrading, but it also reduces the chances of water settling out of the fuel.
Personally, I try to run the fuel tank very low on the last mowing session of the fall. Then I take a small siphon and suck out the last quarter of a tank of gasoline.
This helps suck out some of the dust and other debris that might have found its way into the tank during the summer.
Then I mix fuel stabilizer with fresh premium gasoline in a separate gas can. At that point, I fill the tank until it’s roughly half full.
This allows me to add fresh gasoline with the first session next spring. It’s not something critical, but it helps hedge my bets!
Clean the Deck
I also make it a point to clean away any lingering grass clippings and other organic matter from the underside of the mower deck.
Mice and other small rodents will sometimes be attracted to stuck on grass clippings during a particularly cold and harsh winter.
When they do, they have a knack for chewing on things that they shouldn’t. This includes spark plug wires!
In the case of a riding lawn mower or lawn tractor, I will pull the battery out and bring it into the house.
A battery that is exposed to freezing conditions without proper charging can slowly degrade.
Spring Lawnmower Preparation Is Essential
Spring weather can be fickle. When the trees don’t have any leaves, a rainy day that gives way to a few days of sun can bring your grass out of dormancy with a fervor.
One day you just look outside only to find that things have gotten out of control.
Change The Oil
In a moment like this, it can be tempting to run out to the garage, dump the old gasoline for the snowblower into the lawnmower and just pull the cord.
While you might get away with it once or twice, it’s likely not very good for the long-term lifespan of your lawn mower spark plug or your carburetor.
After a long winter sitting in the garage, your lawn mower’s engine likely needs an oil change, the air filter needs to be cleaned or replaced, and it could do with a good dose of fresh fuel.
If you didn’t add fuel stabilizer to the tank when you put it away, you should add some Iso Heat or a similar fuel conditioner to address any potential water separation in the tank.
Lubricate the Moving Parts
If you have a lawn tractor or riding lawn mower that won’t start, you should also grease the pulleys and bearings. A simple grease gun and two healthy pumps on every zerk fitting will improve operating efficiency.
While this won’t have an appreciable impact on the spark plug, it’s still a wise move for maintaining your investment.
If your riding lawnmower has a battery, you need to make sure it is properly charged before you install it, and try to start the mower for the first time.
From his childhood obsession with gardening to the decade he spent operating a hobby farm, Eric has developed over four decades of experience in self-sufficiency. Not only does this include the organic elements of growing and tending plants, but it also includes a wealth of experience in lawn care, landscaping, and gardening equipment.
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How to fix, maintain be safe with chainsaws, lawn mowers, engines DIY tools and kits. Maybe some beer talk.
Replacing a spark plug for a lawn mower
Lawnmowers are basically engines with a lethal blade that spins around cutting grass as long as there’s gas in the engine and a spark plug that’s combusting the fuel.
But if your spark plug looks like the one above and it’s overworked and corroded, it’s probably not firing properly and it’s time to replace it.
You can tell if your spark plug needs replacing can include:
You may also discover you are using more fuel than you consider is normal for the operation of your mower.
This is a key reason to ensure are spark plug is changed regularly as using excess fuel costs you money and you could be spending it on a chainsaw instead!
The classic problem is of course that the spark plug has failed and you cannot start the engine at all!
If the plug is misfiring, you may notice you may feel combustion is not efficiently happening. This occurs due to the aging of the plug.
As a spark plug ignites, there’s a ‘gap’, in which its reach occurs. This gap eventually widens as a result of repeated use under extreme temperatures, normal wear, and tear. If the ‘gap’ is becoming too large, the unit’s efficiency declines and combustion becomes erratic.
How to replace the spark plug in your lawnmower
What is the correct spark plug for my lawnmower?
This was a good question to ask because even though several different spark plugs may screw into your mower, if it is not the correct type your engine will likely suffer performance problems.
If you don’t know off the top of your head what kind of spark plug is in your mower. look for the number on the ceramic and match it to the brand. The internet is your friend.
Indeed, you can also take the whole unit into a service agent or hardware store and compare so you have like for like.
The best trick is to look at the user manual of the lawnmower for advice.
It is not imperative that use you use your mower brand’s spark plug. You can use a generic substitute or another brand as long as the size and type are correct.
Generally speaking a tried and true brand like a Briggs and Stratton spark plug will work well in most engines.
Battery-powered lawn mowers, like the Greenworks push mower, of course, do not need plugs!
Where is the spark plug on a lawn mower?
Need to know where is the spark plug on a lawn mower? Learn how to maintain it to keep your machine running reliably.
If you’re wondering “Where is the spark plug on a lawn mower?”, it’s likely your machine has broken and you’ve got an overgrown lawn waiting to be cut. Even worse, maybe it stopped working mid-trim, leaving your grass half-mown.
Repairing your lawn mower isn’t just about getting your garden looking neat and tidy. It’s also a great way to save time and money, because you won’t have to research the best lawn mowers or best riding lawn mowers and splash out on a new model. Mending a damaged machine will also help save a repairable tool from going to waste, which is better for the planet.
Lawn & Gardening Tips : How to Clean Lawn Mower Spark Plugs
Even without a breakdown, experts recommend that you regularly check and clean the spark plug, replacing it each year to ensure your mower always starts reliably – so keep reading to find out how.
What is the spark plug?
The spark plug provides the ignition source for a gas-powered lawn mower engine. It sends an electrical current to the combustion chamber which holds the compressed fuel. This current ignites the fuel, triggering combustion and firing up the engine. If you drive a gasoline vehicle, it will also have a spark plug, as spark plugs are an essential component of a traditional combustion engine. While we recommend seeking help from a mechanic if your car or truck needs a new spark plug, replacing this part on a lawn mower is a relatively easy job you can do at home.
On most of the best lawn mowers (such as walk-behind models), the spark plug is typically located near the front of the engine. Spark plugs are usually concealed behind a rubber cap, which protects the part from dust and debris, including stray grass cuttings. This is connected to a short wire, about a quarter-inch thick. It should be easy to find the spark plug on your mower once you have disconnected this wire, which you can do by hand.
On the best riding mowers, the spark plug is also located near the front of the engine, underneath the hood. You will probably need to unscrew and remove the engine cover to access the spark plug. Once uncovered, you’ll see that the spark plug is near the front of the engine, covered by a cap and connected to a short wire, just like on a push mower.
If you’re unsure, check the owner’s manual to see where is the spark plug on a lawn mower from a specific manufacturer.
Signs of a failing spark plug
Trouble starting the engine. The most common sign of a faulty spark plug is difficulty starting the mower’s engine. If using a push mower, you might find you’re having to pull the starter rope more times to get it going. On a riding mower, you may notice that the engine doesn’t start reliably when you turn the key.
Using more fuel. A faulty spark plug could be the reason you are refilling your lawn mower’s gasoline tank more frequently. If the plug isn’t sparking properly, the fuel won’t burn as fully or as efficiently, which can increase your mower’s fuel consumption. You might also notice an odor of gasoline when using the mower caused by the fuel not fully burning.
Engine cutting out. If the engine cuts out immediately after starting, or runs for a while then stops (leaving you with a half-mowed lawn), the spark plug could be the culprit. You might also notice the engine sputtering or popping.
Visible damage. If you examine the spark plug and spot any signs of damage, it will need replacing.
How to check spark plugs
After locating the spark plug on your mower, you need to remove it to check it. Bryan Clayton, CEO and co-founder of GreenPal, says, “Pull off the wire that goes to the top of the spark plug and use a spark plug wrench to take it out. Then you can look at the tip of it and see if it’s dirty or burnt. If it is, you need to clean it or replace it.”
Other common indicators of wear and tear can include a center electrode with a rounded top (this should be flat), cracks in the porcelain sheath that protects the spark plug, or pitting on the firing electrode. A spark plug that’s in good condition will be a light gray or tan color. If the spark plug is covered in black carbon residue or wet from gasoline, it will need a thorough clean.
How to clean spark plugs
Lawn mower spark plugs are inexpensive to buy, so you might find it’s easier to simply replace a dirty spark plug rather than cleaning it. Spark plugs are also readily available from hardware stores or online retailers, which means you won’t have to search too hard to find a replacement.
However, if you need to use your mower and can’t get to the store or wait for a new spark plug to be delivered, it’s possible to clean the existing spark plug. Perhaps you also want to avoid buying new parts when it’s not entirely necessary, to help reduce waste and save money. Either way, it’s easy to clean spark plugs in a few simple steps;
Use rubbing alcohol to cut the grease
Dip the tip of the plug in rubbing alcohol to cut through any oily residue. You can also use a brake cleaner or degreaser.
Scrub the spark plug clean using a wire brush.
Rinse with rubbing alcohol or your chosen cleaning product.
Scrub again if required, then dry the spark plug.
If the spark plug is still dirty, repeat the process until clean.
Keep in mind that cleaning the spark plug may not fix it, as the fault may be electrical. If you refit the clean spark plug and the lawn mower engine still won’t start or continues cutting out, you will probably need to replace the spark plug.
How to replace spark plugs
Before replacing your mower’s spark plug, you’ll need to work out which one to buy. Bryan Clayton says, “You need to get a new one that’s the same as your old one. You can write down the code on your old one, check your manual, or take it with you when you go to buy a new one.” As he explains, most spark plugs have a code on the side which makes it simpler to track down the correct replacement. Most manufacturers produce spark plugs that can be used across mower brands, but if you are unsure, consult the owner’s manual.
Whether you have a walk-behind or ride-on mower, fitting a new spark plug should be quick and simple;
Before inserting the new spark plug, apply a very small amount of anti-seize grease (available from hardware stores). This should ensure the spark plug is easier to remove in the future.
Use your fingers to thread the spark plug into place.
For a secure fit, tighten the spark plug another half or three-quarters turn using a spark plug wrench.