Common Engine Issues and Solutions for Lawn Mowers. Lawn mower fuel tank
Common Engine Issues and Solutions for Lawn Mowers
Owning a lawn mower is like owning a vehicle, sometimes you will experience common issues that are just a part of ownership. Below we will cover a few common engine issues such as what to do if you put the wrong fuel in the fuel tank, what happens if there’s water in the fuel and more. Along with these issues we will also review some solutions to ensure any engine issues are caught in a timely manner and can be fixed properly.
What happens when I mix regular gas with diesel fuel or kerosene in my lawn mower?
Sometimes mistakes happen! If you mess up and put diesel into your gas lawn mower, you can still save your lawn mower. Lawn mowers are low compression so a little bit of diesel shouldn’t hurt anything too much. However, there is a risk that it will cause the mower to smoke rather badly. The best thing to do is to drain your tank immediately, refill it with gas and replace the fuel filter. Once you do so, you should be good to go and can continue mowing. It may smoke for a few minutes as it clears out the remaining bad fuel but should clear up quickly.
It is not recommended to add kerosene to your gas lawn mower, but we also understand mistakes happen. If a little bit of kerosene is mixed with your regular gas, there will not be any noticeable short-term effects. If there is around 15-20% kerosene in your gas tank, your mower is going to run rough at some point, then quit running all together. Repairs will potentially be needed beyond removing the bad fuel and putting in a clean fuel filter.
The best practice is to have multiple fuel cans, each for a specific fuel type. Color coded cans are available (red for gasoline, yellow for diesel, and blue for kerosene), or you can label them with a permanent marker. It’s also a good idea to have a separate can for mixed fuel used in trimmers or chainsaws.
What happens if there’s water in my gas lawn mower engine?
Springtime is a very common season to find water in your mower from condensation in the gas tank. If this water is not addressed, it can get into your lawn mower’s engine and cause some major performance problems. Not only do you risk performance problems, but you also risk some major long-term damages as well. Some of these long-term damages include corrosion in the tank, carburetor and fuel lines. When excessive corrosion happens to these parts of the lawn mower, it becomes very costly to repair.
If water does happen to occur in the engine oil, you can drain it and avoid long-term damage. To drain the water, you will need to start with the crankcase on 4-stroke engines. If water comes out with the oil (it will look milky in color), you will need to add some light oil, turn the engine over a couple times using the starter, and drain it again. Remove the spark plugs first, to discharge any oil from the cylinders and to make sure it does not start during the process.
What does it mean if my lawn mower is smoking?
Sometimes you will notice your lawn mower is putting off black exhaust smoke. The gasoline to air mixture is regulated in the lawn mower’s carburetor. If there is not enough air getting into the carburetor, then there is a higher ratio of gasoline which results in black exhaust smoke.
If your lawn mower does start smoking like this, you do not need to panic. The most common cause of a smoking lawn mower is a clogged or dirty air filter. When the air filter is not clean, the carburetor is unable to pull the proper amount of air in to keep the correct ratio of gasoline to air. Once the mower is shut off, check and replace the air filter and give it another try.
Routine maintenance (at least once a year) is key to avoiding many issues. A fresh oil change and new filters are inexpensive, and far less than major repairs. Consult your operator’s manual for a list, or contact us for assistance.
Where can I find lawn equipment maintenance and repair services?
Finding lawn equipment maintenance and repair services for equipment does not have to be time consuming or overwhelming. The expert technicians at Koenig Equipment are trained to fully inspect your mower and repair any and all issues so schedule the service you need today.
Written by Boland Media
How to fix a plastic gas tank on a lawnmower, step by step
Most lawnmowers use a gas engine. They make the machine powerful with high endurance. If the tank is empty, you refill and continue. However, sometimes the plastic gas tank that contains the gas may get cracked. It can be hit by something, but the gases released by the fuel weaken the tank’s walls as well. This makes it more vulnerable to a crack over time.
Cracks can result in fuel leakage that can be hazardous. But a plastic gas tank can be fixed reasonably quickly and easily at your home.
How to fix a plastic gas tank on a lawnmower, step by step:
- Step 1: Remove the fuel out of the gas tank
- Step 2: Detach the gas tank from the lawnmower
- Step 3: Locate the crack on the gas tank
- Step 4: Clean the area around the tank
- Step 5: Fill the crack with melted plastic, or use glue or fiberglass
- Step 6: Reattach the fixed tank to the lawnmower
We recommend going through the entire article as all the details to the before-mentioned steps are discussed in more detail underneath.
- 1 Materials Required:
- 2 Step 1. Remove all the fuel out of the gas tank:
- 3 Step 2: Detach the gas tank from the lawnmower:
- 4 Step 3. Locate the crack on the gas tank:
- 5 Step 4. Clean the area around the crack:
- 6 Step 5. Fill the crack:
- 6.1 – Method 1. Melt the area around the crack using a soldering iron:
- 6.2 – Method 2. By melting a small piece of plastic into the crack:
- 6.3 – Method 3. Use glue or fiberglass to fill the crack:
- 8.1 1. How can I tell if there is water in my lawnmower’s gas tank?
- 8.2 2. Why is my lawnmower isn’t getting any gas?
Materials Required:
The following materials will be required to assist you in fixing the plastic gas tank efficiently and successfully:
- Soldering iron
- Hacksaw
- Screwdriver
- Safety goggles
- Protection gloves
- Sandpaper
Step 1. Remove all the fuel out of the gas tank:
Step 1. Park the mower at a suitable location: Park the lawnmowers at a place that can deal with some gas spillage. When you remove the gas tank, it is always possible that some of the fuel spill on the ground.
Step 2. Remove the gas: Remove the gas tank’s cap. Empty the gas tank by disconnecting the fuel line. Another method would be to siphoning the gas from the tank. Make sure that that all the gas is entirely removed from the tank.
Step 2: Detach the gas tank from the lawnmower:
Step 1. Remove the gas tank: The gas tank is attached to the lawnmower’s body with some screws. Remove these screws with the help of a screwdriver, and detach the gas tank.
Step 2. Remove the fuel fumes from the tank: The fuel fumes also need to be removed entirely from the gas tank before starting the main procedure. Take an air compressor pipe and blow air inside the gas tank. This shall remove all the fumes from the gas tank.
The gas tank’s cap should remain removed during the entire process of the tank’s fix. This is done to avoid the creation of any internal pressure inside the tank.
Step 3. Locate the crack on the gas tank:
Step 1. Fill the gas tank with some water: In most cases, you will spot the crack easily. But when this is not the case, close the hole at the bottom connected to the fuel line. Fill the gas tank with water, and keep filling the tank until you spot the leakage point. If that does not work, you can try to increase the tank’s pressure with some help from an air compressor. Use some cloth to decrease the air leakage near the fill cap.
Step 2. Mark the leakage point: Mark the area around the leakage point or the crack using a marker.
Step 3. Remove the water from the gas tank: Remove the water you just used to find the crack from the gas tank, and let it dry.
Step 4. Clean the area around the crack:
Step 1. Position the gas tank on a flat surface: Place a wooden plank or something else below the gas tank, and position it in such a way that the crack faces towards you.
Step 2. Polish the crack’s surface: Grab a small piece of sandpaper and polish the crack so that the crack’s surface becomes even and it becomes more visible.
Step 3. Clean the area around the crack: You need to use soldering iron on the area around the crack, so that area must be clean. Clean the area around the crack by putting some rubbing alcohol on a cotton swab.
Step 5. Fill the crack:
There are three possible methods to fill the crack and, thus, fix the gas tank, depending upon the crack’s size and the thickness of the tank’s walls. All methods will be discussed in more detail below.
– Method 1. Melt the area around the crack using a soldering iron:
This method is used when the gas tank is made from thick plastic. Make sure that the plastic can be melted by trying it on a small part first. See if it indeed melts, and when dried, gets its strength back. When this looks ok the step-by-step procedure to use this method is as follows:
Step 1. Switch on the soldering iron: Switch on the soldering iron, and wait until it’s heated. If the soldering iron can be set at different temperatures, start with a low temperature first.
Step 2. Melt a small trench using the soldering iron: Melt a small trench on the crack in such a way that the soldering iron doesn’t go through the tank; instead only melts the surface.
Step 3. Scoop the plastic into the trench: Now, melt some plastic surrounding the trench, and use a small tool to push this melted plastic into the trench and the crack. Keep doing this until the groove is filled with melted plastic completely.
Step 4. Recheck for any leakage: Fill the fixed gas tank with gasoline, and close the tank’s cap. Shake the tank and check if the leakage exists. Let us tell you something; you won’t see any leakage if you have applied this method step by step.
– Method 2. By melting a small piece of plastic into the crack:
This method can be used when your gas tank doesn’t have thick plastic walls. The step-by-step procedure to apply this method is as follows:
Step 1. Cut a tiny piece of plastic: Some gas tanks have additional plastic around the area of screw holes. Using a hacksaw, cut a small piece of plastic from this area. If extra plastic isn’t available on the gas tank, you may cut a tiny piece from any other thing at your home, which isn’t of any use to you.
Step 2. Switch on the soldering iron: Switch on the soldering iron, and wait until it’s heated.
Step 3. Melt the cut piece into the crack: Place the tiny plastic piece you have just cut on to the crack. Now using a soldering iron, melt this piece, and force the melted plastic into the crack. Keep doing this until the crack is filled with melted plastic.
Step 4. Recheck for any leakage: Fill the fixed gas tank with gasoline, and close the tank’s cap. Shake the tank and check if the leakage exists. But we bet that you won’t see any leakage if you have followed the steps mentioned above correctly.
– Method 3. Use glue or fiberglass to fill the crack:
If melting plastic does not work well in your case, you can fill the crack with something else. You can try to use a glue that can cope with gas. Another material would be fiberglass. Clean the environment from the crack well, and use sandpaper to roughen the area. Then use glue or fiberglass to repair the crack.
Step 6. Reattach the fixed gas tank to the lawnmower:
You have now successfully fixed the lawnmower’s plastic gas tank and can fill in the fuel without worrying.
Related Questions:
How can I tell if there is water in my lawnmower’s gas tank?
- Left in the rain: The presence of water in the gas tank is one of the main reasons which halts the lawnmower from starting. It may not be only because the lawnmower was left out open in the rain but also because the gas in the tank condenses, thus creating moisture.
- Sudden stall: One of the water-contaminated fuel indications is that the lawnmower suddenly stalls during its operation.
- Smoke from the engine: Another indication is the emittance of a comparatively more significant amount of smoke from the lawnmower’s engine, resulting from low fuel combustion inside the piston chamber.
- Check with a flashlight: A flashlight can also check the presence of water inside the gas tank. Take the lawnmower in a shady area or indoors, and then shine the light on the tank. Water being heavier than fuel, settles at the tank’s bottom and forms tiny bubbles. These bubbles can easily be spotted with the help of light.
- Drain the gas: Such contaminated gas must be drained from the gas tank immediately, as water can corrode the engine and carburetor’s metallic parts. After the drainage of water-contaminated fuel, dry the gas tank completely using compressed air.
- Keep the gas cap closed: It is also advised to keep the gas tank’s cap closed to avoid the entrance of any moisture inside the tank.
Why is my lawnmower isn’t getting any gas?
There might be multiple reasons that stop the supply of fuel to the lawnmower. A few significant causes, along with their solution, are mentioned below:
- Check for cracks: First of all, you need to check the gas tank for any breakage or cracks. The cracks cause fuel leakage, and thus the lawnmower can run out of fuel within minutes. You need to fix the gas tank or buy a new one in this case
- Clogged filter: Another reason that may cause this issue is a clogged filter. There is a filter between the carburetor and the fuel tank, which stops any dirt or debris from entering into the carburetor. This filter may get clogged with time and eliminates the fuel supply to the lawnmower. The filter must be cleaned, in this case, to continue the supply of fuel to the lawnmower
- Closed valve: Some lawnmowers have a valve that stops the fuel supply to the carburetor. It is often turned off at the end of the season or when the lawnmower needs to be repaired. Make sure that this valve is not turned off
- Clean the carburetor: Despite multiple efforts to halt the entrance of dirt into the carburetor, old gasoline can still form a film inside the carburetor, thus stopping its working. A malfunctioned carburetor will stop the supply of fuel to the lawnmower’s engine. You need to open the carburetor and clean it from inside using gasoline and a brush gently.
Final Remarks:
You don’t need to buy a new gas tank if it’s a little cracked, thanks to the methods mentioned above that can be used to resolve your problem. Gasoline leakage not only drains the fuel faster but can also be hazardous as it is highly flammable. So, it’s advised to get it fixed as soon as possible. Also, don’t forget to wear protective gloves to protect yourself from unnecessary burns and cuts. Safety goggles must also be used to protect your eyes from toxic fumes. All the tools used in the process must be kept out of children’s reach to avoid accidents.
How to Get Water Out of a Lawnmower Gas Tank, step by step
Even when you check the weather forecast or rain radar regularly, it is always possible that you unexpectedly get into a shower. When you quickly get inside, you leave your lawnmower outside, and it will get wet. Usually, this is not a problem, but when water or moisture somehow get into the fuel tank, it is a different story.
It is always suggested to store your lawnmower in a nice safe shelter, so your machine is safe from environmental hazards. Keeping it out in rainy weather or a damp shed may cause it to quit working at some time. If you have forgotten to store your lawnmower after using it, it is exposed to some rainy weather, and it does not start. It can be an indication that water has seeped into the gas tank. To fix this, you have to remove all the water from it.
How to get the water out of a lawnmower gas tank, step by step:
- Step 1:Diagnose if there is Water in Your Lawnmower
- Step 2: Disconnect thespark plug
- Step 3:Siphon the diluted gas
- Step 4: Dry the tank
- Step 5:Drain the oil
- Step 6: Empty the carburetor bowl
- Step 7: Dispose of all the diluted oil
- Step 8: Refill the tank
- Step 9: Use a fuel additive to combat moisture in your tank
Once you have realized that there has been water contamination to your lawnmower’s gas tank, there is no need to panic. The problem is not difficult to fix. Make sure you do not ignore the problem, as it can cause severe damage to your engine. Long term damage to the lawnmower may include corrosion in the tank, fuel lines, and the carburetor.
Water in the lawnmower’s gas tank can be due to it being left out in the open when it was raining, and some rainwater seeped into the gas tank. Another possibility is that your lawnmower is stored in such a warm place during daytime and is cold at night that it makes a partial vacuum that sucks moist air into your tank. There it condenses and settles down at the bottom of the tank.
Although lawnmowers are made waterproof, there is always the chance for accidents like these to take place, particularly when the lawnmower is older.
Get the water out of the lawnmower gas tank in 9 easy steps.
Step 1: How to diagnose if there is water in your Lawnmower.
The first thing to do is to confirm that your lawnmower has water contamination in its gas tank. If your lawnmower has one (or more) of the following problems after being exposed to rain or a damp environment, there is a high chance it is caused by water in your gas tank:
– Hard Starting
Water is denser than gas, sinks at the bottom of the gas tank, and most of the lawnmowers’ models draw gas from the tank’s bottom. Hence, when you start the lawnmower, the gas tank’s water will go into the carburetor before fuel and cause problems.
– Poor Performance
When the quantity of water in the fuel is not very significant, the engine will start fine. But the water can result in poor performance and will not accelerate like it should when throttled.
– Continuously starting and sputtering
When the water in the fuel tank is in small amounts, the engine will start smoothly, but your mower may suddenly sputter or stall or completely stop running. Often it may yet start again, but the same thing may happen again.
– Fuel System Damage
If you notice any problems in the performance caused by the accumulated water in the lawnmower’s fuel system, check your engine as soon as possible. If you are too late, it may inflict significant damage to your engine. You can protect your lawnmower from any damages such as corrosion or rust over time.
– Smoke coming from the engine
Sometimes you may also notice an unusual amount of smoke coming out from the engine, which can be due to poor combustion in the piston chamber.
Step 2: Disconnect the spark plug.
The first thing you must do is to remove the spark plug for safety purposes.
Step 3: Siphon the diluted gas.
The second step is to siphon the diluted gas out of the lawnmower. For this purpose, insert the siphon tube of a hand-pump into the gas tank of the lawnmower. Insert the drain tube of the pump in the container where you will collect the diluted gas. Now pump the device and extract all the gas from the tank.
Step 4: Dry the tank
Although you have extracted the gas, there may still be a little water attached to the walls inside the tank. So, carefully dry the tank with a dry piece of cloth, or you can also use compressed gas or by spraying it with a WD-40.
Step 5: Drain the oil.
Now the next step is to drain the oil. Tilt the mower by propping up the front of the mower on blocks. And pun a collecting pan under the machine’s drain plug, which is located at the underside of the mower.
Unscrew the plug with a wrench, and wait for all the oil to drain out into the pan. If there is no drain plug, lift the carburetor from the side on which the air filter or the carburetor is located and pour the oil out from the oil fill hole.
Step 6: Empty the carburetor bowl
Now empty the carburetor bowl. It is a metal cylinder that is usually located on the side of the mower. Wipe thoroughly all around the bowl with a dampened rag with carburetor cleaner to not let the dirt from falling once it is removed.
Also, place a rag under the bowl to catch the liquid. There will be at least one set bolt present. If you find a second offset bolt, then it is a drain plug.
If there is no drain plug, then unscrew the bolt and pour out the carburetor bowl’s contents.
Step 7: Dispose of all the diluted oil.
Collect all the diluted gas and the oil and dump them at the local hazardous waste recycling facility.
Step 8: Refill the tank
Now reconnect the fuel line and refill the tank with fresh gasoline and engine oil.
Step 9: Use a fuel additive to combat moisture in your tank
If you live in an area where moisture is a problem using a fuel additive could be the right solution. An example of such a fuel additive is HEET. It is specially made to remove water from your gas tank.
This method may be more costly, but if it means you can avoid damage, your lawnmower will be avoiding it is more than worth it.
Note: Make sure that there is more gas than water in your tank. Else the fuel additive will not work. Check the fuel additive manual for more information.
Related Questions:
1) How did the water get into my gas tank when I never left it out in the rain?
Although your lawnmower has never been left out in the rain or may not have been in contact with water, water still enters the gas tank by condensation.
This phenomenon occurs in the winters, usually when you leave your lawnmower in a damp and humid place.
For this issue, you should tightly close the opening of your tank so that no water can seep in. Also, try not to store your lawnmower in such places and try to buy a plastic cover for your lawnmower.
2) Why is my lawnmower oil milky?
If the oil color from your lawnmower is ‘whitish milky,’ then it is contaminated with water. The oil with greenish milky color is because of the presence of antifreeze in it. If the addition of water to the oil is due to condensation of water in the engine, then the milky white color should disappear when you warm the landowner.
3) Are lawn mowers waterproof?
A lawnmower can not be completely waterproof. However, water can still be used to clean your land mowers. Landowners are designed to tolerate a little bit of rain on the lawnmower’s engine.
After the rain, turn on the mower and heat it for a few minutes. The engine’s heat will evaporate the water and clear the moisture, which will protect the motor from the rust.
Final Remarks:
Although your lawnmower may be waterproof, water can still enter your lawnmower’s gas tank (by the causes mentioned above). The best way is to drain out the water contaminated fuel and refill it with the new one. The alternate yet slightly more expensive method is to use the fuel additives. Both of these methods are fine, and you should choose which one fills your needs.
So the best way to avoid this inconvenience is to keep your lawnmower at a dry place in winters. You can also buy a plastic cover to protect it and be sure to close the opening of the tank tightly. Taking serious precautions is better than facing severe damages to your machine or following a rigorous step to fix it.
Is It Bad for A Lawn Mower to Run Out of Gas?

Spring is here. The April sun melts the snow and ice, and before you know it, it’s time to prep your yard for summer. That means busting out the lawn mower to give your grass a much-needed trim.
Unfortunately, lawn mowers don’t have fuel gauges. So, it’s difficult to tell when it’s time to fill up on gasoline. You’d think that the solution to your problem is simple, right? You simply have to refill the tank, and you’re good to go. But, for some reason, your mower won’t start even after you fill it.
Don’t worry. Keep reading to learn what the problem may be and how to get your mower running like new.
Your Lawn Mower Has a Dirty Carburetor
So, your lawn mower isn’t starting after running out of gasoline. One of the first things you should check is your carburetor.
When you run through your gas tank, your mower will start sucking up the debris that’s sitting at the bottom of your fuel tank. While your mower should have a fuel filter, the sediment lying at the bottom of the tank is usually so fine that it can get through the filter.
All you have to do is clean the carburetor bowl to fix this problem. Typically, you can locate the carburetor bowl just behind your mower’s air filter.
If draining the carburetor bowl doesn’t work, you most likely have a failed carburetor that needs to be replaced for your engine to start correctly.
There Is an Airlock in Your Lawn Mower’s Fuel System
An airlock is one of the common causes why your mower won’t start after running out of fuel.
An Airlock occurs when air replaces fuel in the fuel lines. As you refill your fuel tank, you could push the air towards your mower’s carburetor, which keeps the new fuel from reaching the engine.
To fix this problem, ensure you fill your fuel tank to the very top with new fuel or try draining the carburetor bowl as described above.
You’ve Filled Your Lawn Mower with Bad Fuel
Another reason why your mower may not be starting is that you refilled it with bad fuel. If not treated with stabilizers, most fuels only have a shelf life of about three to six months. So, if you’re using gasoline from last summer, you may want to replace it.
If you believe bad fuel is the culprit, drain your fuel tank and replace it with new fuel.
Refill Your Lawn Mower Properly with EZ-POUR /h2>
Are you fresh out of fuel? Do you need a safe, reliable, and clean way to refill your lawn mower? Well, EZ-POUR has the solution for you. To fill your lawn mower and other small lawn equipment, we recommend using our Replacement Fuel Spout Vent Kit.
We also offer several other styles of spouts perfect for refilling hard-to-reach tanks and tanks with narrow or wide openings, all quickly and efficiently. Visit our website today to see more of what we have to offer!
Combined Manufacturing, Inc. 18451 Centaur Rd.Wildwood, MO 63005