Too Much Oil In Lawn Mower? Read Our Easy Fix It Guide!
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What happens with too much oil in the lawn mower? Well, too much of a good thing can be bad for you! Right? Well, the same law applies to lawn mowers and engine oil. An overfilled lawn mower oil tank will lead to performance problems, failed starts, or an oily overflow mess. And much worse!
So, what other engine issues arise from putting too much oil in a 4-stroke lawn mower? And are these issues easy to fix?
Too Much Oil In Lawn Mower
Overfilling a lawn mower oil tank will negatively affect engine performance and possibly prevent the mower from starting. Too much oil in a lawn mower can easily clog the air filter, foul spark plugs, and potentially cause a hydro-lock, which could bend the connection rods in a multi-cylinder mower.
The way 4-stroke oil works in a 4-stroke walk-behind single-cylinder mower or a multi-cylinder lawn tractor is surprisingly straightforward:
- Lawnmower engine oil lubricates the engine and helps to keep it cool.
- The oil tank on a lawnmower feeds oil into the crankcase, where it is placed under pressure by the down-stroke of the piston during the combustion process.
- The air pressure forces the oil upwards to lubricate the piston and cylinder, as well as the crankshaft and con rod (piston push rod).
- The crankcase has a ventilation valve (breather) that releases pressurized vapor, which forms an oily mist.
- A rubber hose connects the ventilation valve to the mower’s air filter housing and carburetor air intake.
- The crankcase vapor passes through the air filter to the carburetor, where it mixes with the gasoline that fuels the engine.
What Happens When You Overfill the Oil In Your Lawnmower?
Too much oil in a lawn mower crankcase causes the vapor released via the ventilation valve to become oil-rich, which clogs the air filter, creating an overly rich air-to-fuel ratio that fouls the spark plugs and causes the engine to smoke and run poorly. Extreme over-oiling will stall the engine.
With too much oil in the mower’s oil tank, an excess amount of oil feeds to the crankcase, effectively reducing the volume (air space) of the crankcase, which increases the pressure in the crankcase during the piston down-stroke.
- The increase in pressure will force the excess oil through the ventilation valve into the air intake. From there, it will clog the air filter.
- The oil-rich vapor (potentially pure oil in extreme cases of over-filling) will enter the carburetor and blend with the gasoline that powers the engine.
- The overly rich air-fuel mixture will enter the combustion chamber and foul the spark plugs, causing the engine to sputter and stall.
- A severely over-filled lawnmower oil tank (and crankcase) will cause a hydro-lock, where the piston cannot move due to excess oil filling the combustion chamber (between the cylinder head and the piston crown).
- A hydro-lock has a similar effect to a seized engine – the engine stalls and won’t restart.
- Attempting to crank the engine of a multi-cylinder mower when hydro-locking has occurred could bend the con rods (piston push rods).
- Hydrolocked single-cylinder lawnmower engines generally don’t suffer con rod bending.
How Do You Know If You’ve Put Too Much Oil In Your Lawn Mower?
You’ll know you’ve put too much oil in your mower when:
- The oil on the dipstick is above the upper indicator line.
- Excessive smoke emits from the exhaust.
- The engine runs roughly and sputters.
- The engine stalls and won’t restart.
- The spark plug is oily.
- The air filter is oily.
Can You Put Too Much Oil In Your Lawn Mower?
Yes! You can put too much oil in a lawn mower if you fail to limit the volume of oil poured into the oil tank to the amount specified by the mower manufacturer. And filling oil into the mower directly from a large oil can without checking the dipstick as you fill the tank can lead to over-filling.
Note: Consult your lawn mower owner’s manual for the correct oil volume and grade.
Oil volume ballpark – Lawn mower oil volumes generally vary between 15oz to 20oz, ranging from single-cylinder walk-behind mowers to larger multi-cylinder ride-on mowers.
What Are the Risks of Overfilling a Small Engine With Oil?
The risks associated with overfilling a small engine with oil include the following.
- Bent con rods – which may require expensive engine repair!
- Your lawn mower air filter may spoil.
- Your lawn mower spark plugs risk soiling.
- Wasted oil – the ultimate sin for thrifty homesteaders!
What to Do When You’ve Put Too Much Oil In the Lawn Mower? Easy Fix!
The best way to fix an overfilled lawn mower is to drain the engine oil from the oil tank, crankcase, and combustion chamber. Remove the air filter and spark plug and clean them to remove all traces of oil. Crank the engine several times with the spark plug removed to purge residual engine oil.
How to Fix a Failed Mower Engine Due to Oil Overflow?
Do you need to fix a lawn mower that’s stopped running due to oil overfilling? Then follow these steps.
Get the Right Tools, Including the Following:
- A jug or can of the specified oil for your mower.
- A spark plug wrench.
- A screwdriver or wrench. These tools help to remove the air filter.
- A wrench! Wrenches are perfect for removing the oil drain plug.
- Pliers to remove the ventilation hose.
- A solvent. It helps to clean the lawnmower spark plug.
- Detergent! Warm water with grease-cutting soap works fine. It helps to clean the air filter.
- A plastic funnel.
- An oil drain pump – but only if the mower lacks an oil drain plug.
- An oil drain hose – is critical for ride-on lawn tractors.
- An oil drain pan.
- A measuring jug.
- Paper towel.
Troubleshooting Your Lawn Mower – Step-by-Step
- Disconnect the spark plug boot and remove the spark plug from the engine.
- Remove the air filter cover and ventilation hose.
- Remove the air filter.
- Clean the spark plug.
- Clean the air filter and dry it with a paper towel.
- Lightly oil the air filter to prevent it from drying out and perishing.
Drain All the Oil From the Crankcase and Oil Tank – Step-by-Step
- Remove the oil drain plug (on the side of the engine or under the deck) and drain the oil into an oil drain pan (large mowers may need an oil drain hose to attach to the oil drain valve).
- Pump oil out of the oil tank (for mowers without an oil drain plug) into an oil drain pan or disposable bottle.
- Tip the mower on its side with the oil tank cap removed (for mowers without a drain plug). And drain oil from the oil tank and crankcase into an oil drain pan.
- Crank the engine several times to vent oil vapor from the spark plug hole and crankcase ventilation hose.
- Let the mower stand with the spark plug, oil drain plug, and air filter removed for 45 minutes to evaporate oil-vapor residue.
- Refit the cleaned spark plug, air filter, and ventilation hose.
- Screw in the oil drain plug.
- Pour the manual-specified amount of oil into a measuring jug (you can DIY a used canned fruit tin or similar).
- Fill the oil from the measuring jug into the oiling tank via a funnel.
- Allow the oil to settle for two minutes.
- Screw in the dipstick and oil cap.
- Unscrew the dipstick and check the level. Top up if necessary. But don’t go over the upper marker line on the dipstick.
- Screw on the oil tank cap.
- Crank the engine. The mower should start.
- Allow the mower to idle for a few minutes.
- Smoke will emit from the exhaust as the engine burns away the remaining oil residue.
- Stop the mower and check the dipstick. Top up the oil if necessary using the measuring jug.
- Cut the lawn!
Conclusion – Re-Oiled and Ready to Mow
If you’ve overfilled oil in your lawn mower, don’t beat yourself up – it’s a common mistake! And, the remedy needn’t cost much more than the price of a new can of oil.
Irrespective of what type of mower you own, having the right tools for the job and following our step-by-step oil overfill fix will get your mower back into the field. Pronto!
In the meantime, let us know if you have more questions about what to do if you put too much oil in the lawnmower.
We have tons of experience tinkering with lawn mowers, tractors, engines, and small farmyard equipment.
And we’re always happy to help troubleshoot.
Too Much Oil In the Lawnmower References, Guides, and Works Cited:
Dan is our qualified diesel fitter and automotive mechanic. He’s been fixing machinery for over 30 years and has a real passion for the old stuff. he loves reviving things that others have given up on. He’ll fix anything with a cable tie and fencing wire and has had his hands on everything from log skidders, trucks, agricultural implements, tractors, and huge mining gear to outboard motors. He’s plagued by OCD. but that makes him a helluva mechanic! View all posts
Paul writes for a living, about trucks mostly. He lives away from the city and off the road, nurturing his love for all things outdoors –- like tiny house construction, country cooking, bushcraft, woodwork and power tools, alternative energy, and minimalist living. If there’s a way to Do It Yourself, Paul wants to hear about it, and try it out. Then he’ll write about it, and share his story with blog readers around the world. Paul was raised on a South African homestead where he tended two horses, a Jersey cow, and half a mile of split pole fencing. At age 16, he bought a dirt bike, pirated a punk rock compilation, and commenced a blind-rise adventure that continues to this day where words, Wabi-Sabi, cooking, all-terrain tires, and all things to do with canvas and wood are his fodder. His overarching existential question is – “What more does a man need than a cast iron pot and a pair of loose-fitting trousers?” View all posts
Does My Mower Need Oil? – beginners guide with pictures
Engine oil is the most important item to check on your mower. Nothing kills an engine as quickly as a low oil level, but it’s important to get it right, too much oil is also bad for the motor.
A mower engine requires oil if the oil level reads below the low-level oil mark on the dipstick. A dipstick has two oil levels indicating marks, the upper mark indicates the full level, and the lower mark the low oil level. Add oil until it reaches the upper oil level mark on the dipstick.
In this post, you’ll learn how to check your mower oil level and also how to add oil including oil type and quantities. This post should have the subject covered pretty well, but if you need video help, check out “Mower oil check video”.
Checking Mower Oil Level
Checking the mower oil level should be undertaken before every use, it only takes a moment of your time and could potentially save you hundreds of dollars. Oil lubricates and cools your mower engine, when a mower runs out of oil, the engine builds so much heat it fuses the internal components together, a condition known as seizing the engine and its terminal. The process for regular walk behind mower and ride-on tractor mower is identical.
Checking the oil should be performed while the engine is off and the mower is parked on level ground.
To check mower engine oil level, follow these simple steps:
Locate – Locate the dipstick
Clean – Remove and clean it. To remove a dipstick, turn it anti-clockwise.
Read – Refit dipstick and remove to read dipstick level.
Locate Dipstick / Oil Filler
The dipstick is usually located on the side of the mower engine. The dipstick cap is generally marked with the word oil or oil can symbol and often a contrasting color. The dipstick is also the oil filler location.
Locate – Dipstick in yellow here.
Reading A Dipstick
The upper mark identifies the full level and the lower mark the low oil level. The upper and lower marks may be letters, words, holes, or stamped lines. Between the high and low marks, you may see a hatched area. This area denotes an acceptable oil level zone, however, it is always best to have the oil level reach the upper dipstick mark.
Dipstick Markings – Dipstick markings vary, but all follow the same principle – upper is full mark and lower mark is low.
Some dipsticks employ a hatched area in-between to identify an acceptable oil level zone.
It’s important to note, while there are many styles of high and low dipstick markings, there are just two main dipstick seat flavors, threaded or winged. Do not thread home a threaded type dipstick in order to dip for oil. Doing so gives an incorrect oil level reading. See pics below or check the oil check video here.
Threaded – Threaded dipstick seat
Threaded – Do not thread to check the level
Correct Oil Level – Oil level correct (Top hole). Nice work!
Oil Low – Oil level below the critical low oil level mark (lower hole). Add oil now.
Oil Too Full – Too much oil, remove excess oil.
Adding oil is simple, fill the oil through the dipstick tube. Some dipstick tubes may be small and awkwardly located, if that’s the case you’ll need a funnel (MacGyver funnel – cut the base off a plastic drinking bottle). When filling oil just remember to add a little and recheck the oil level, repeat until the oil level reaches the upper mark on the dipstick.
Adding too much all at once will cause the dipstick to read over the full mark. Overfilling is a common error and most think it can’t hurt any, but they are wrong.
Add a Little Check
While too much oil is better than too little, too much can still cause some problems. From empty, most mower engines won’t hold more than.65 of a quart. Ideally, a mower should get a tune-up once a year, which includes an oil change. I wrote a complete post with pics and instructions on the subject and you can check it out here.
You’ll also find a video on “Mower tune-up” here.
Symptoms associated with too much oil include:
- No start
- Pull cord hard to pull
- Starts and stalls
- Runs with lots white smoke
- Oil leaking from muffler
- General oil leaks
The first task before working your mower is to remove the spark plug wire, this prevents accidental starting. Removing oil can be a little messy, especially if you’ve just added a little too much. Knowing how much to remove is hit and miss. Most modern mowers will allow oil to drain by tilting the mower on its side, engine oil flows out through the dipstick tube. You can check that out in this video, it covers a mower tune-up.
Older mowers will have a regular oil drain plug under the mower where the blade is located and that type is messy. I prefer to use an oil extractor siphon, which makes the task simple and you use it on other jobs like draining the gas tank. If you need a siphon, I recommend the Briggs Stratton oil and gas siphon, it’s good quality at a fair price and you can check it out on the “Small engine tools page”.
Oil extractor, the preferred method.
Mower Oil Type
Mowers will run perfectly well with car engine oil. It is of course better to use the oil type specified by the engine maker 5W30 or 10W30 works great for mower engines.
- Briggs and Stratton oil type – 5W30
- Honda oil type – 10W30
- Kohler oil type – 10W30
- Tecumseh oil type – 5W30
- Kawasaki oil type – 10W30
Check out the Amazon link below for lawnmower oil delivered to your door.
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.
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This Happens When You Don’t Change Oil in a Lawn Mower
You forgot to change the engine oil in your lawn mower. Now you want to know what damage can happen to your engine. I have seen many failed lawn mower engines due to running dirty oil in my years as an outdoor power equipment service manager.
There are many people who are under the misconception they don’t need to change the engine oil in their lawn mower. This is so not the case. The oil in the engine does more than people think.
If you don’t change the oil in your lawn mower, the oil becomes very dirty and breaks down. The oil loses its cooling agents and detergents which can cause significant damage to your engine.
People often don’t think about putting money into their mower until the mower doesn’t start or encounter other engine problems. Give your mower a little bit of attention once or twice a year and you will be surprised how long that mower can last you.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
What Does Engine Oil Do in a Lawn Mower?
The average lawn mower’s small engine only holds about 3/4 to 1 quart of oil. This engine oil is usually an SAE30 weight oil. That little amount of oil has a lot of work to do in such a small space.
Remember, it’s only getting cooled by the air revolving around the engine. That means if it’s 80 degrees outside, your oil is already going to be that warm.
Oil will break down over time. All the cooling agents and detergents in the oil will eventually disappear or break down. The ingredients in our oils are designed to do a lot of things:
- Acts as a cooling agent that keeps the internal parts of your engine cool while it is building heat from friction
- Acts as a buffer between moving parts. These moving parts build heat in the engine.
- Acts as a cleaner. It keeps carbon and broken down oil from clogging up oil passages in the internal routes of the engine. If these routes get plugged oil cannot get through which can damage the engine.
What Happens When I Don’t Follow Manufacturer’s Oil Change Guidelines?
Most small engine manufacturers say engine oil should be changed every 25 to 50 hours of use. The hourly interval depends on the capacity of the engine and how hard it gets used.
Sometimes when you use the mower harder and longer than normal the temperature of the engine will rise considerably. Running oil in an engine to higher-than-normal temperatures is when weak oil has a chance to fail.
When the oil in your engine gets overheated it becomes black and thick in consistency. This thick black oil bakes onto the internal parts of the engine. Oil can no longer flow over and around these parts as easily as it was designed to.
Taking time to change your engine oil regularly will ensure your engine lasts more than a couple of years. The price of a quart of oil is a pretty inexpensive insurance policy. Think about all it does to protect the engine and its components.
Should You Replace the Engine or Replace the Lawn Mower?
Remember, if you don’t change your engine oil you could end up with the expense of replacing the engine. The engine is the main component of your lawn mower. If it fails, you need to consider a couple of options before making an additional investment in your mower.
Should you replace the engine or replace the lawn mower? You will want to take the expense of a new engine and the life span of the mower into account when deciding to make a significant engine purchase.
An engine can be replaced in a lawn mower without too much trouble with the installation. The cost will be the biggest factor you will want to consider before purchasing a new engine.
A replacement engine will cost anywhere from 200.00 up to 2,700.00 depending on the manufacturer and horsepower.
Replacement engines can be purchased online or from your local engine dealer. Engines can look similar when shopping on the internet, but it may not be the correct engine you need. Make sure you have your model and spec number to purchase a compatible engine.
You will also need these same numbers if you want to order parts for your engine. If you are unsure whether you are selecting the right engine online, you may want to purchase from an engine dealer.
The knowledgeable staff at the dealership will be able to assist you in finding an engine that will fit. You should consider, in addition to cost, the condition of your mower.
Are you going to have to put a lot of money into the frame, shell, or deck of the lawn mower anytime soon? It may be more cost-efficient to purchase a new mower rather than put additional investment into an old mower.
Why am I Always Adding Engine Oil to My Mower Each Time I Mow?
It’s always good to check the level of your engine oil before you mow. If you find yourself always adding oil to your engine before you go out and mow that’s not always a drastically bad thing, but it’s also not a good thing. You need to find out why you always have to put oil in your engine.
You may be adding oil to your engine each time you mow because you have an oil leak, your engine is burning oil or your engine is using oil. You need to identify which one of these scenarios applies to your engine oil loss.
- Oil Leak – Look over the engine area to find signs of an engine oil leak. Once you find the cause of the leak, replace the gaskets from which the oil is coming leaking. You will also want to inspect your filter if your mower uses one. Make sure your oil filter is sealing properly.
- Burning Oil – Check for a plugged air filter. A plugged air filter will cause oil to burn from the engine making the engine work harder. You can clean the air filter or replace it is very dirty and unable to be cleaned.
- Using Oil – An engine can be using oil due to overheating while in use. It can also be an indication of a valve or ring problem. You need to take your mower to a repair center for an engine diagnosis.
Items Needed for an Engine Oil Change
Selecting the Correct Engine Oil
Make sure you select the correct engine oil before your oil change. Most gas-powered small engines will use SAE30 oil with the exception of Kohler engines.
What happens to oil in a lawn mower when you never change it? THIS!
Kohler engines will need a 10W-30 due to the hydraulic lifter inside the engine. Most engines take 3/4 of a quart and up to 2 quarts for larger engines.
Oil Collection Container
Find an item to collect the oil in. A drain pan is best. If you don’t have a drain pan, find a container that has a large enough capacity to hold the used oil and will not leak all over the floor.
Also, make sure you have a closed container for the used oil to take to a recycling center.
You can use empty oil containers. Do not use milk or soda containers. Never dispose of engine oil in the landfill, in your drain, or on your property.
You will need to get the correct size socket or wrench to remove the oil plug. Some plugs are square while others will be a hex plug in varying sizes. A funnel will make adding new oil a lot easier. You will also need a filter wrench if your engine uses a filter.
If your engine is a better type of engine, it will have an oil filter on it. Find a compatible filter for your engine. Refer to your owner’s manual for OEM filters.
If you choose to use an aftermarket filter, there are several websites available to cross reference the OEM filter part number to an aftermarket part number. I always use an OEM filter on my lawn mower engine.
If you choose to use an aftermarket filter, my customers have had good results using Stens brand.
Other Helpful Supplies
Cardboard or newspaper is useful to keep oil from getting on your work surface. It is also good to have rubber gloves and rags on hand.
Details on How to Change Engine Oil in a Lawn Mower
For more in-depth information on changing engine oil in a lawn mower, refer to one of the information topics:
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What Happens If You Don’t Change Oil in Lawn Mower
Since most small motors are designed with no oil filter, dirt from combustion and intake dust build up and degrade the oil and its lubricity. Then, the dirty old oil starts performing its functions less effectively and requires a change to bring back the lawn mower to its full and efficient capacity. But, what happens if you don’t change this oil? Despite the fancy advertising, no oil lasts more than a year as its functional properties are exhausted. The degraded oil allows for increased wear within the engine parts, and eventually, results in permanent damage when the engine seizes. Considering this potential harm, how soon should you change your oil? What oil should you use? How long can the engine run before permanent damages? Let’s delve into the simple 30-minute maintenance service that could save you from replacing your mower or make it last years.
Do You Really Need to Change Lawn Mower Oil?
Due to the numerous heated and continuously moving parts, internal combustion engines are reliant on lubrication to ensure they continue to work without tearing apart or grinding to a halt. Once your lawn mower is oiled, its efficiency improves, its lifespan extends, and you deal with fewer repair costs. Simple engines, no matter how small, such as those in lawn mowers, feature many moving parts designed to operate at very high speeds and temperatures. Changing the oil in your lawn mower ensures you get rid of dirt and debris, which slow down and ruin your engine. It is therefore paramount that you follow the manufacturer’s guidelines when it comes to oiling your lawn mower.
When Change the Oil in Your Lawn Mower?
Considering you are out for the best performance of your lawn mower, changing oil is an essential undertaking that works best scheduled, regularly, and following the manufacturer’s guidelines.
To ensure the lawn mower’s reliable and long-lasting service, replace the oil and oil filters (if your mower contains any) at least once during every mowing season or after about 50 hours of use. This applies to when the manufacturer does not provide details. Otherwise, the owner’s manual provides guidelines specific to your model.
You should also keep track of your oil levels using the dipstick, a reliable way to ensure you always have clean and sufficient amounts of oil in your mower. Overfilling the oil in a bid to ensure you don’t have to refill it regularly is one good way to ruin your engine. The excess oil may drown the crankcase or cause the engine to overheat. Although it isn’t as bad as having bad oil, it continuously affects your engine.
How to Know If Your Lawn Mower Needs Oil?
Lawn mowers burn oil much more quickly than cars. If you’re cutting tall or wet grass, make sure you are using even more oil. Most manufacturers recommend checking your oil regularly to ensure your lawn mower is always running efficiently and with a cold engine.
A cold engine is one whereby you’ve let the engine time to drain oil into the crankcase so you can get a better reading of your oil levels. However, the process of checking both the hot and cold engines is generally the same, so no need to worry about the technicalities.
Here is how to check your lawn mower’s engine oil level, whether it does or doesn’t feature dipsticks.
Lawn Mowers without Dipsticks
Some lawn mowers may not feature a dipstick to help you find out the oil level. This may look like it makes the process tougher, but it is actually much easier to do with such lawn mowers. Here is how it goes:
- Wipe the area around the cap with a clean rug, as with all openings to the engine components.
- Remove the cap without breaking the mechanism. On engines featuring a dipstick, this piece is attached to the cap, which rotates into a groove to lock. This may simply be a pop-off and on the cap.
- Check the oil level in the fill hole. The oil should be near or at the top of a slot used to indicate the highest level.
- Top up the oil until it is at the same level as the top of the slot, replace the fill cap, and lock to ensure no dust nor dirt gets in.
How to Change Oil in a Lawn Mower?
Now that you’ve checked your oil level and have discovered it needs a change, how do you go about it? Do you siphon it out or is there some special machine to do it? Well, the process is fulfilling for some as a weekend activity but requires a bit of hands-on.
The tools you’re going to need are:
- Some newspapers or plastic sheets to cover the work area.
- A socket wrench or spanner fitting the drain plug
- A spark plug wrench
- A shallow container for the drained oil
- Some pieces of cloth for cleaning up
- Bricks or some timber to raise the lawn mower off the ground.
- Find some open or sizable area, like the floor of your garage or your driveway.
- Place the protective materials, such as newspapers, to ease the cleaning once you are done.
- Run the lawn mower for some time to warm up the oil. This makes the oil less viscous and more fluid so you can drain it more easily. Do this to drain the gas tank as well so there won’t be any spills while you work on the lawn mower. About 15 minutes of warming should do the trick, so add just a little amount of fuel to run for that short time.
- Shut down the engine and disconnect the spark plug. This ideally ensures the engine doesn’t start, should you mistakenly turn the blade.
- Drain the old oil into a container. It may require you to simply unscrewing an oil drain plug on the underside of the sump or tilting the lawn mower and draining it through the oil fill plug. Check the instructions from your manufacturer’s guide to ensure you use the recommended draining method.
- Place the drain plug back, remembering to tighten it right, but not too tight, as you could split it if it is plastic or ruin the thread on the sump if it is metallic.
- Make sure you use a funnel to channel the oil without making a mess when you add the recommended type and amount of oil.
What Oil Should You Use for Your Lawn Mower?
Different manufacturers usually recommend specific oil types for their products depending on the engine’s size and technology. However, some general specifications can help you out in case you are in limbo. The following are some guidelines to help out.
If you have a small or medium-sized mower, you will probably need about 17 to 20 ounces (500 to 600 mL) of oil, depending on the measurements used in your region. For most engines, SAE 30 or 10W30 multigrade oil efficiently supports their running. For the larger engines, you may have to use 15W40, which is more viscous when hot.
Changing Oil for the Winter
One often overlooked practice conducted by lawn mower owners is the de-winterizing process. This involves, among other activities, the changing of oil to ensure the engine’s components do not get ruined over the winter. However, although the process is simple and shouldn’t take more than a day, it extends your lawn mower’s life by multiple years.
The following steps should help ensure your lawn mower starts with ease after winter ends:
- Change your oil. After the mowing season, your old oil is full of soot, gasoline, moisture, and acids, which can corrode the engine’s components over the winter. Thus, change your oil and run the lawn mower for a few minutes to coat the components with clean coats of oil.
- Drain or brim your gas following your manufacturer’s instructions. The leftover gas could corrode your carburetor or clog the fuel system. Follow the model’s manual as some manufacturers recommend completely filling up with fresh, stabilized gasoline.
Add fresh stabilized fuel – Don’t add stabilizer to old fuel as it won’t bring it back to life. A stabilizer should be added to fresh gas instead. The process is simple. Add fuel stabilizer to an empty fuel can. Add fresh fuel and thoroughly mix the stabilizer into the fuel. Fill the lawn mower with this gas to ensure the fuel filling the carburetor bowl is stabilized gas. You can then top off the gas tank and store the mower.
What Happens If You Run Your Mower Without Oil?
While you regularly need to refill your lawn mower’s gas tank, oil never comes up in one’s mind. It is reliant on a schedule or change in season and might sometimes not be the most reliable way to keep your engine healthy, as you might easily forget or get held up on other activities like work, shopping, or traveling. So, what happens if your lawn mower runs out of oil?
Oil is an essential part of all engines, whether large or small. Its key function is to keep the moving parts lubricated to reduce friction between them and keep the engine’s temperatures under control. If the engine oil runs out, friction between the moving parts of the engine will increase, causing overheating, fusing of pistons, and seizing of the engine. This damage is almost always irreversible.
Since most lawn mowers are made as simple as possible, they will even start without oil, and you’d be very lucky to notice any problem early on. If it’s dirty and contains old oil, you can replace it. And if it’s fresh but finished, you can simply top it up. Unusual noises and engine knocks are signs you need to do some repairs as some damages have already been done.
How to Know If Your Engine Has Seized?
After running a mower and hearing noises and the mower turning off on its own, cross your fingers because you could have caused your engine to seize. In this case, pull the starter cord. If it is moving, the engine is turning, and thus, the mower is still good. This is, however, not foolproof as sometimes the engine will not seize until it has cooled down.
Another way to check if the engine has seized is to try and turn the cutting blade. Make sure to take out the spark plug first lest you lose a finger or two. If it turns, the engine is still good. On the other hand, if it is jammed in place, start budgeting for a new mower.
How Long Can Your Lawn Mower Run Without Oil?
Domestic lawn mowers seize quicker as they sit for long periods between uses. Thus, the oil settles in the sump. The difference is however negligible as both commercial and domestic mowers will seize up in less than five minutes.
If you are lucky enough to notice and shut it down before the engine seizes, top up the oil before it cools and seizes up. This is, however, not reliable, and most times, the engine seizes up as it cools anyway. One thing to note is that lawn mowers will not smoke due to having too little oil. Smoke is caused by the lawn mower burning off excess oil, hence why low oil levels will not cause smoke emission.
Will Your Lawn Mower Automatically Shut Down Because of Low Oil Levels?
Considering most lawn mowers do not have an oil switch, they do not automatically shut down. The more modern models, however, may have a switch to ensure damage is prevented by low oil levels. However, it should only back up your regular oil maintenance practice. This will ensure you also run on clean oil, which in turn, ensures you enjoy your lawn mower much longer.
Your lawn mower’s engine may start even if you have zero oil in it. While the newer models are designed not to start if their oil checking mechanism fails, most models will start. You’ll probably hear a knocking noise right on start up, which will give you a very short window to shut it down and prevent any irreparable damage.
Once your engine seizes up, your chances of repairing this damage are very slim and costly. You may even shut it down in time but have it seize as it cools. The damage usually consists of parts fuse rendering the engine into a hunk of pretty much worthless metal. Disassembly and lubrication are a good trial, although, for the most part, the lawn mower is usually a write-off.
All machines with moving parts, from bicycle gears to motorized engines or sewing machines, need oil to ensure the parts do not grind to piles of metallic ash. A lawn mower is no different despite its compact size. It is, therefore, good practice to follow a schedule and constantly check the oil levels before and after prolonged use to ensure you do the minimum, if any, intentional damage to it.
How to check your lawn mower’s oil level