You’re mowing along like usual when your zero-turn mower begins sputtering and stops running. Of course, it never happens at a good time and most likely in the middle of cutting your lawn. So, now you need to find a fix so you don’t fall behind on your mowing.
A Gravely lawn mower will start and then die when old fuel is restricting fuel in the fuel lines, carburetor, and fuel filter. A clogged air filter, bad ignition coil, dirty spark plug, plugged mower deck and plugged cooling fins can also cause a Gravely mower to shut down while running.
Stay safe while diagnosing and repairing your Gravely. If you are unsure of your mechanical skills and don’t understand how to complete the repair, it’s best to contact a professional mechanic to avoid injury or creating bigger problems on your mower.
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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.
12 Reasons Your Gravely Lawn Mower Starts Then Dies
Bad or Old Fuel
The type of gas along with the age of that gas can negatively impact your Gravely mower. Most gas contains ethanol.
This is an alternative fuel that makes gas a little environmentally friendly. It’s okay to use in most vehicles, but it isn’t good for the small engine in a Gravely mower.
This is because ethanol naturally attracts moisture to the fuel system. This ethanol and moisture can cause corrosion and fuel restrictions due to the water content and leaving gummy deposits behind clogging fuel components.
Over time, this water and ethanol mixture will separate from the gas and sink to the bottom of the fuel tank. This can be damaging to your Gravely when this mixture runs at extreme temperatures through the engine.
Because gasoline begins to break down rather quickly, always purchase fresh gas and use it within 30 days. Add a fuel additive to stabilize your fuel to make it last a little longer if you are unable to consume it within this time period.
Running old gas or the wrong type of gas through your mower will cause fuel restriction and component failure resulting in a mower that dies after starting. Use an unleaded gas in your Gravely mower that has a minimum octane rating of 87 and a maximum ethanol content of 10%.
Never use gas that contains high levels of ethanol. A low ethanol content or ethanol-free fuel is best. For more information on the right gas to use in your mower, check out “This is the Gas to Use in Your Gravely Lawn Mower“.
Solution: If you find the fuel in your Gravely mower is old, drain the fuel tank using a fuel siphon pump. Refill the tank with fresh fuel with a fuel additive like Sea Foam Motor Treatment to stabilize the fuel, clean the fuel system and reduce moisture.
Read more about Sea Foam and why I use it in my lawn mower here.
Plugged Air Filter
You run your mower in dirty conditions and your Gravely tosses dirt and debris into the air. This can plug the air filter when it isn’t cleaned or replaced regularly. The airflow to the engine will become restricted and cause your mower to quit and shut down.
A Gravely mower requires clean air to run. The air filter is an important part of keeping your engine clean by preventing dirt from entering the air intake. I recommend replacing your air filter once a year when performing your routine annual service.
Keep the filter clean by removing and cleaning it several times throughout the mowing season. Never use your Gravely without an air filter, even if it’s for a short period while you source a new replacement filter.
Even a small amount of dirt in the engine can result in engine damage and a significant repair bill.
Solution: Clean your air filter by removing it from the air filter housing. Be careful not to let any dirt or debris fall into the air intake. Wipe out any dirt remaining in the housing and in the air filter cover with a dry cloth. Proceed with the following instructions:
Clean a Gravely Mower Paper Air Filter Element:
- Tap the filter against a solid surface to loosen and remove as much dirt as possible.
- Hold the filter up to a light source to check if you can see light shine through the filter. If you can, go ahead and reuse your air filter. If you cannot, you must purchase a new filter.
- Install the air filter and reinstall the cap on the filter housing.
Plugged Fuel Filter
A fuel filter is installed on your Gravely mower to strain the fuel as it leaves the fuel tank. It prevents dirt and other contaminants from entering the fuel system. Dirt and gummy deposits can clog the fuel filter when it isn’t regularly changed or the fuel is very dirty.
A clogged fuel filter will prevent a sufficient supply of fuel from passing through the filter into the fuel line. This will prevent the engine from getting the fuel it needs to keep running. It can begin to run sluggish and die.
I recommend replacing the fuel filter on your Gravely mower annually.
Solution: If you find your fuel filter is plugged, stop your fuel flow, remove the filter, and install a new one. You will find an arrow on the side of your fuel filter.
Make sure this arrow is pointed in the direction of the mower’s fuel flow. This means a correctly installed fuel filter will point toward the carburetor and away from the fuel tank.
Clogged Fuel Lines
As I mentioned earlier, old gas can leave behind sticky gummy deposits that can clog the fuel lines preventing fuel from flowing to the engine. This will cause your Gravely lawn mower to die while mowing.
Check each section of the fuel line by shutting off your fuel flow using the fuel shut-off valve. You can also use pinch pliers to crimp the fuel line to stop the flow.
Isolate a section of the fuel line you need to check. Remove the end of the line that is furthest from the fuel tank and place it in a container. Start your fuel flow. (Make sure the container is placed lower than the fuel tank because fuel cannot run uphill without the help of the fuel pump).
If you find you have sufficient flow into the container, shut off the fuel flow and reattach the fuel line. Continue checking additional sections of the fuel line. If you don’t find a problem in the fuel lines, keep checking the other fuel components for a restriction or failure.
Solution: When you don’t get good fuel flow from the fuel line into the container, check each section of the fuel line and the fuel filter that could have a blockage. Once you isolate the blockage to a specific section of the fuel line, shut off your fuel flow and remove that section of the line from the mower.
Spray carburetor cleaner into the line to help loosen the blockage. Follow this by blowing compressed air through the line to remove it. Repeat as necessary. If you are unable to clear the blockage, replace the line with a new fuel line.
The carburetor’s main purpose is to regulate the amount of fuel mixed with air to form combustion. When the carburetor doesn’t work properly, your mower can start and then die.
The carburetor becomes dirty from running old fuel that sits in the carburetor causing gummy and hard deposits to form. This can cause components on your carburetor to stick or clog so it is no longer able to function properly.
Solution: Before you tear your carburetor apart, make sure you are getting fuel to the carburetor. Once that is confirmed, remove your air filter and spray carburetor cleaner into the air intake. Start your Gravely.
If you find it starts and then dies after burning the carburetor cleaner, disassemble the carburetor and clean it. Follow the steps in this guide to clean your carburetor.
Plugged or Broken Cooling Fins
Your Gravely mower can start and then die when your mower’s engine gets hot. Check your engine cooling fins. They may be plugged with debris or broken.
The cooling fins exist to push air around your engine block and cylinder head to keep it cool. Plugged cooling fins can restrict the amount of air circulating around your engine.
Solution: Take caution working around your hot engine. Remove any debris stuck in the cooling fins. Replace any broken fins. Clean debris around your engine and engine shroud. Ensure your heat shield is attached securely.
Insufficient Engine Oil Level
Your mower requires a specific amount of engine oil in the crankcase for the engine to run at its best. Most people know you can develop problems when your engine oil becomes too low, but don’t know you can also have problems if there is too much oil in the crankcase.
Too Much Engine Oil
Next, check the engine oil level in your mower. Too much engine oil in your Gravely lawn mower will cause pressure to build in the crankcase. This can cause your mower to overheat and shut down.
Remove some engine oil through the drain plug or oil filter. You can also use an oil evacuator or turkey baster to suck oil through the engine oil fill area.
You can also remove a little oil from the oil filter or drain plug. Check the engine oil level on the dipstick. Continue to add or remove oil until the oil level is at the full line on your dipstick.
Too Little Engine Oil
You may have developed an engine oil leak or have a problem in your engine where it is using or burning oil. When you don’t have enough oil to keep the internal engine parts sufficiently lubricated, friction starts to build creating heat.
This heat can overheat your engine and cause it to die. The heat can be so hot, your internal engine parts will start to melt.
Here’s the bad news: If your engine shuts down because of a lack of engine oil, chances are significant damage was done. Your best solution here is to take your mower to an experienced small engine mechanic to tear down your engine and perform tests to determine how much damage was done.
Bad Spark Plug
A dirty or fouled spark plug on your Gravely can cause it to run sluggish and die. Not only will a dirty plug cause this problem, but a plug that is damaged, not properly gapped, or doesn’t securely have the wires attached can cause your mower to stop running.
Solution: Clean your spark plug tip. If you find the tip of your spark plug is very dark, has a burnt electrode, or is damaged, replace your spark plug. Make sure the plug is gapped following the engine manufacturer’s specifications.
Securely attach your spark plug wires. Spark plugs are not very expensive. These should be replaced annually.
Bad Ignition Coil
The winding on the ignition coil can separate and short out when your mower is hot. When this happens, the spark plugs are unable to get the voltage they need to create spark. This can cause your mower to die after it’s been running for a while.
Solution: Identify a bad ignition coil using an ohmmeter to check for a break in continuity. Replace the ignition coil if you find there is a break.
Incorrect Choke Position
The choke reduces the amount of air your engine receives. This is used when starting a cold engine to allow more fuel and less air to form combustion.
Solution: The choke lever must be placed in the off position after the engine is warm to allow additional airflow or the mower will die.
Bad Gas Cap
A gas cap that can no longer vent allowing air to pass through the cap can restrict fuel flow and cause your Gravely mower to shut down. When the vent in the gas cap is plugged, the fuel tank forms a vacuum not allowing gas to flow to the engine.
Run your mower with and without the cap for periods of time to see if your cap is the cause of your Gravely mower dying.
If you remove your fuel cap and your mower starts and runs and then replace your cap and your mower eventually shuts off, you may have a problem with your cap.
Solution: You can try to clean your fuel cap to remove the clog or just replace it with a new fuel cap.
Plugged Mower Deck
A mower deck that is plugged full of debris can cause your Gravely lawn mower to shut down. This is because the engine must work harder to turn the blades through a deck full of debris. This can cause your engine to overheat and shut down.
Solution: Prevent this from happening by regularly scraping your deck to keep it clean. Avoid mowing in wet conditions as wet grass clumps and sticks to your mower deck. You can try using a deck spray to minimize grass buildup.
Deck sprays are not a miracle product that prevents all buildup, but they can minimize the amount of debris collecting under the deck.
Why is My Gravely Lawn Mower Battery Not Charging?
Make sure you are running your Gravely at a high engine speed. Don’t allow your mower to idle for long periods of time. It requires the power of the engine to charge your battery.
If you continually have to charge your battery and have confirmed the battery and wiring are in good condition and securely attached, you may have a problem with the charging system.
Solution: There are some steps you can take to check the condition of your battery and charging system which I explain in this article. If after performing these tests, you find you have a bad battery, replace your battery.
When you find the charging system isn’t working right, I highly recommend having an experienced mechanic diagnose and repair the problem.
There are so many components that can cause the charging system to fail that, unless you know the charging system, parts can be thrown at it hoping it repairs the issue. Electrical components can get expensive and they most likely can’t be returned because they are electrical parts.
Still Experiencing Problems with Your Gravely Lawn Mower?
Own a lawn mower long enough, you’ll start running into problems with it starting, not continuing to run, smoking, leaking gas, giving a bad cut, vibrating, or another issue.
To help you save time and money, I have put together a guide to help you troubleshoot the next problem that develops on your Gravely mower.
You can find this guide at Common Gravely Lawn Mower Problems & Solutions.
If you are unsure how to perform diagnostics and repairs on your Gravely lawn mower safely, it’s best to have a professional complete the repairs.
This will help you avoid personal injury or additional damage to the mower. Your local Gravely lawn mower dealership or lawn mower repair shop will be able to help you solve your problem.