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14 Reasons a Lawn Tractor Starts Then Dies

A lawn tractor is a piece of equipment that will make property maintenance easier. You can cut the lawn, collect leaves, remove snow and even more tasks with your lawn tractor. When your lawn tractor stops running, you quickly realize how much you miss its functionality.

A lawn tractor will start then die when it isn’t able to get the air, fuel and spark required to create a combustion in the engine cylinder. A dirty carburetor, bad fuel, plugged air filter, faulty fuel pump, bad ignition coil and plugged mower deck can cause a lawn tractor to die after running.

Keep reading for more items that can cause your lawn tractor to die after it has been running. Always follow safety precautions as outlined in your lawn tractor owner’s manual before attempting to work on your tractor.

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Follow all safety instructions provided in your equipment operators manual prior to diagnosing, repairing or operating. Consult a professional if you don’t have the skills, knowledge or are not in the condition to perform the repair safely.

Reasons Your Lawn Tractor Starts Then Dies (FIXED!)

No one likes when their lawn tractor dies in the middle of the mowing season. Beginning each season with a full routine service can help prevent many problems that will cause your lawn tractor to die.

Lack of Fuel in Your Lawn Tractor

Everyone knows if you don’t have fuel, your lawn tractor will not run. However, when you’re frustrated and trying to figure out why your tractor died, you may forget the simple stuff like checking the fuel.

You may have developed a fuel leak causing your lawn tractor’s fuel tank to empty sooner than usual. Your lawn tractor may also die when running it on a hill. In this case, fill your fuel tank so you don’t continue to have troubles on the hill.

Fix: Add fresh fuel in your lawn tractor.

Bad Fuel in Your Lawn Tractor

Make sure you are using the right type of gas in your lawn tractor. A gas-powered lawn tractor requires an unleaded fuel with a minimum 87-octane rating and a maximum 10% ethanol content. This gas lasts about 30 days before it starts to break down and lose its effectiveness.

A corn-based product added to gas, known as ethanol, attracts moisture. This is not good for the small engine and fuel system in your lawn tractor. This ethanol and moisture solution can cause gumming and degradation of the fuel system causing fuel restrictions.

This solution will also separates from gasoline over time and sinks to the bottom of the fuel tank. Running this solution through your small engine can cause it to get extremely hot and shut down.

To minimize problems resulting from bad or old fuel, use fuel within 30 days. Add a fuel additive to stabilize your fuel when you are unable to use it within this time frame. A product like Sea Foam Motor Treatment stabilizes the fuel, reduces moisture and cleans the fuel system. Read more about the advantages of using Sea Foam in your lawn tractor here.

Fix: Drain your fuel tank using a fuel siphon to remove old fuel and place it in an approved container for recycling. Fill with fresh fuel and add Sea Foam Motor Treatment to reduce moisture and clean the fuel system. Run your lawn tractor for a few minutes to help get the treated fuel running through the fuel lines and components to help remove moisture.

Dirty Carburetor on Your Lawn Tractor

The carburetor is used to regulate the fuel to air mixture allowed to enter the cylinder to create a combustion. Components of the carburetor can gum up and stick so it doesn’t function as designed. The lawn tractor will run sluggish or shut down when it isn’t able to get the fuel it requires.

Fix: If you are somewhat mechanical, you can attempt to clean your carburetor to get it working again. There are a lot of little parts to work with. If you are not sure if you can handle it or would just rather have someone else take care of the issue, bring your carburetor to your local repair shop to be cleaned or rebuilt.

Read my steps on how to clean your lawn tractor carburetor here

Plugged Fuel Filter on Your Lawn Tractor

The fuel filter screens the fuel to keep dirt and foreign debris from entering and damaging the fuel system. The fuel filter can become plugged preventing fuel from flowing through the filter.

Fix: Replace the fuel filter. There is a right and wrong way to install a filter. Make sure the fuel filter is installed with the arrow, located on the side of the filter, pointed in the direction of the lawn tractor’s fuel flow.

Bad Fuel Pump on Your Lawn Tractor

Your lawn tractor requires the use of a fuel pump because the gas tank sits lower than the carburetor. It needs the fuel pump to work against gravity to get fuel to the carburetor.

Check for damage or leaking around the seams of the fuel pump. Overtime, fuel can cause the seams of the pump or the pump itself to fail. Internal damage will be hard to spot, so you will need to test your pump to check its operation.

Fix: To check your fuel pump, use the fuel shut-off valve located at the bottom of your fuel tank to start and stop fuel flow. Hose pinch pliers can also be used to crimp the hose to stop fuel flow.

First, check to make sure you are receiving fuel to the pump. With the fuel shut off, remove the line from the inlet port of the fuel pump and place it in a container. Start the fuel flow. You should have fuel running into the container. If there isn’t fuel running out of the hose into the container, you need to look for any blocked lines or plugged filter.

Once you have flow to the pump, reattach the fuel hose to the inlet port. Second, you’re going to check to see if you fuel pump is working to get fuel up to the carburetor. Do this by removing the fuel line from the carburetor and placing the end in a container.

Start your lawn mower and your fuel flow. You should be receiving a steady or pulsating flow of fuel out of the fuel line if your fuel pump is still in working.

If you aren’t getting fuel flow, shut off the mower and shut off the fuel valve. Make sure you don’t have any blockages in the fuel line to the carburetor. If nothing is plugged it’s time to replace the fuel pump.

Blocked Fuel Lines on Your Lawn Tractor

Fuel lines can get clogged from dirt and buildup left behind from old fuel. Use the methods above to start and stop fuel flow to check for blockages in the fuel lines. You should replace your fuel line if you notice the lines are becoming dry and cracked. You can purchase fuel line online or at your local hardware store.

Fix: To clear the line, remove the fuel line from your lawn tractor. Spray carburetor cleaner into the line to help loosen the clog. Next, blow compressed air through the line to remove the blockage. Repeat spraying carburetor cleaner and blowing air through the line until the line is no longer plugged.

Reinstall the unblocked fuel line. If you are unable to clear the fuel line, purchase and install new fuel line.

Bad Fuel Cap on Your Lawn Tractor

Something as simple as a fuel cap can cause your lawn tractor mower to die. Fuel caps are designed to vent. When the vent is blocked, a vacuum is created in the fuel tank which restricts the amount of fuel flowing through the fuel tank. 

Fix: Remove your fuel cap and start your lawn mower. Allow your run. If your lawn tractor no longer dies, replace the fuel cap and continue to allow your mower to run for a while. If your mower dies with the cap in place, the cap can be your problem.

You can try to see if you can clean the cap to allow it to vent. If you cannot, you need to replace the fuel cap.

Plugged Air Filter on Your Lawn Tractor

Your lawn tractor engine requires air to run. The air filter keep dirt and grass from entering the engine. This filter must be changed and cleaned regularly. When it becomes plugged, your lawn tractor is starved of fuel and will shut down after running.

A plugged filter doesn’t only cause your engine to shut down, but it can result in your engine to overheat causing internal engine damage

Fix: I recommend starting each season out with a new air filter. Clean your filter several times through the mowing season.

Follow these steps to clean a paper air filter element:

  • Remove the filter from the air filter housing.
  • Wipe out any dirt that is left in the housing using a clean dry cloth. Don’t let any dirt fall into the air intake.
  • Tap your air filter against a solid surface. What you are trying to do is loosen as much dirt as possible to remove it from the filter. Never use compressed air to clean your filter. This can damage it.
  • Hold your filter up to a light source to see if you are going to be able to use it again. If you can see light shine through the paper element, reuse the filter. If not, purchase a new filter
  • Install the filter and replace the cover on your filter housing.

Dirty or Damaged Cooling Fins on Your Lawn Tractor

Cooling fins can become damaged or packed full of grass and mud. When this happens, the fins are no longer able to circulate the air around the engine block to keep it cool. When this happens, your Husqvarna could die in the middle of mowing.

Fix: Remove the engine cover and clean the cooling fins. Replace any damaged fins. 

Insufficient Engine Oil in Your Lawn Tractor

Not only can too little oil in the crankcase cause your lawn tractor to shut down, but too much oil can do the same.

Too much oil in your lawn tractor can cause your engine to smoke and die while mowing. The smoke can clog your air filter causing your engine to look elsewhere for air. Too much oil in your lawn mower can cause significant damage including internal engine damage and the possibility of having to replace your engine.  

Too little oil in your lawn tractor will cause additional friction in the engine that can cause your engine to overheat and die. 

Fix: Check the engine oil level using the oil dipstick. To get a good reading on the dipstick, wipe the stick off with a dry clean cloth and reinsert into the crankcase. Remove and read the level as indicated on the stick.

When your oil level is too high, remove a little oil to correct the oil level. You can do this by draining a little oil from the drain plug or oil filter. You can also use an oil evacuator or even a turkey baster to remove a little oil.

If your oil level is too low, you can change your engine oil and fill it with fresh oil. This may not fix the problems you have from running your tractor with low oil. Most likely, if your lawn tractor overheated and shut down due to low oil, you have caused engine damage. You should have a small engine mechanic troubleshoot your engine problem.

Dirty Spark Plug or Loose Wires on Your Lawn Tractor

A fouled spark plug covered in carbon or oil can cause your lawn tractor to run intermittently and die. Loose spark plug wires or a plug that is gapped incorrectly can also cause running problems.

Fix: Remove the spark plug and clean it if necessary. If the plug is very dark in color, has a burnt electrode or cracked porcelain, you are better off replacing it with a new plug. Make sure it is gapped correctly and the wires are securely attached.

Bad Ignition Coil on Your Lawn Tractor

The winding on the ignition coil can separate and short out when the lawn tractor gets hot. When this happens, the spark plugs are unable to get the voltage they require to create spark. This can cause your lawn tractor to die after getting hot.

Fix: Identify a bad ignition coil using an ohm meter to check for a break in continuity. Replace the ignition coil if you find a break.

Choke is in the Wrong Position on Your Lawn Tractor

A choke on your lawn tractor allows more fuel into the combustion chamber by restricting air flow. This is needed to start a cold engine. If you leave the choke on after your engine heats up, your lawn tractor will die.

Fix: Make sure to adjust the choke to the correct position once your tractor heats up.

Plugged Mower Deck & Dull Blades on Your Lawn Tractor

A mower deck that is packed with grass and other debris can cause the engine to have to work harder because it needs to rotate the blades through the buildup under the deck. Running dull blades can also have the same effect putting more load on your engine that can eventually cause it to shut down.

Fix: Inspect your lawn tractor mower deck for any damage. Scrape the deck to remove debris and sharpen the blades. Always run your lawn tractor at full throttle when cutting grass. Avoid cutting wet grass. 

Still Having Problems with Your Lawn Tractor?

You can encounter many different types of problems with your lawn tractor as it ages. I have put together a guide to help you quickly identify the causes and solutions for the type of problem you are encountering. I cover common problems like a lawn tractor not starting, smoking, cutting uneven, vibrating, dying after running, and more.

Check out my guide: Common Lawn Tractor Problems & Solutions.

If you encounter a problem you don’t feel comfortable troubleshooting or repairing, contact your local lawn tractor dealership or repair shop for assistance.