The Lawnmower or Zero Turn Starts Up but Quickly Fails to Operate

I’m sure you can relate to the frustration I felt when my lawnmower suddenly stopped working in the midst of the yard. Some of the most frequent causes of mower breakdowns in the middle of mowing are detailed here.

When a Simplicity riding mower or zero turn starts but quickly dies, it could be because of a clogged air filter, dirty carburetor, defective fuel pump, clogged fuel filter, dirty spark plug, bad ignition coil, wrong engine oil level, clogged cooling fins, or a clogged mower deck.

Read on for some other potential sources of your starting issues.

To avoid injury, use the Simplicity in accordance with the instructions in the user handbook. The ignition key and spark plug wires must be disconnected. Stop everything you’re doing until the engine is completely cool.

12 Causes of Your Simplicity Mower Starting Then Dying

Using Stale Gas Or The Incorrect Fuel For Your Simplicity Mower

There isn’t much time before gas starts to degrade. As soon as 30 days after your purchase, you can do this. This is why gas should be used within 30 days of purchase.

Ethanol is a component of most gasoline. This fuel is an alternative to traditional gasoline that can reduce harmful emissions. Even though ethanol has environmental benefits, it should not be used in your Simplicity small engine.

Water vapor in the air is drawn to the fuel system because ethanol is present. Over time, the ethanol and water combination will leave behind a varnish that clogs fuel filters or corrodes other parts.

Make sure you’re using gas that has an octane value of 87 or above and contains no more than 10% ethanol at all times. Avoid using E15 and E85 gasoline, which contain 15 and 85 percent ethanol, respectively.

You can extend the gas’s stability by using a fuel additive, such as Sea Foam Motor Treatment. This is an additive that should be used with new gas. The effects of used gas are not reversible.

For more information on Sea Foam’s benefits, see Use Sea Foam Fuel Additive in a Lawn Mower to Stabilize Fuel.

The ANSWER is to get rid of the stale gas in your Simplicity’s tank. Put in new gas and a fuel stabilizer made to keep the fuel system clean and prevent moisture buildup.

Simplicity Mower with Clogged Fuel Filter

To prevent debris and other contaminants from entering the fuel system, an inline fuel filter is installed in series with the fuel lines.

This is a wearable component that needs to be replaced every year. When it isn’t, debris might build up in the filter and impede gasoline flow.

Your Simplicity will sputter and eventually stop working if you don’t keep it fueled up.

FIX: switch out the fuel filter. Follow the direction on the filter’s plastic casing for proper installation. When installing, make sure the filter’s arrow points in the direction of gasoline flow.

Causes of Simplicity Lawnmower Fuel Line Clogs

You can clog your carburetor and gasoline lines in the same way. Water condenses in the fuel system when ethanol is present.

This sticky residue is left behind when the moisture evaporates and might clog the gasoline line. Because of this, the gasoline supply to the carburetor may become restricted or cut off altogether.

Find a blocked fuel line by opening and closing the fuel shut-off valve and observing the fuel flow.

The answer is to disconnect the fuel line from the mower and flush the blockage out once you’ve located it.

Clean the line by spraying carburetor cleaner. This is done to break up the obstruction. After that, you can try blowing compressed air into the gasoline line to see if that helps clear it out.

You should try again if necessary. If the blockage cannot be removed or if breaks appear in the gasoline line, you should switch it out with a new section of fuel line of the same diameter and length.

A Simplicity Lawnmower with a Bad Fuel Pump

When the carburetor is mounted above the fuel tank, a fuel pump is essential for moving gas from the tank to the carburetor. This is due to the fact that gasoline must be pumped in order to travel upward.

Your Simplicity could have stopped working due to a number of factors, one of which being a faulty gasoline pump. To transfer gas from the tank to the carburetor, a vacuum fuel pump makes use of the engine’s exhaust vacuum.

Damage to the pump, such as cracks, will cause it to stop working and necessitate replacement.

To figure out if the gasoline pump is broken, you can start and stop fuel flow with the fuel shut-off valve or clamps.

Once you’ve confirmed fuel is reaching the pump, you may check to see if it’s being pumped to the carburetor.

Take the fuel line off the carburetor and put it in a container. Begin operating the lawnmower while keeping an eye on the fuel line within the container.

When the fuel is flowing steadily or pulsates, you know the fuel pump is working properly. If your gasoline pump has developed cracks or is no longer functioning, you should have it replaced.

Simplicity Lawnmower with a Filthy Carburetor

The carburetor combines the fuel and the air necessary for burning. When the mower breaks down, it could die.

The varnish that builds up in gasoline systems over time can lead to problems like stuck or corroded internal parts. There is a widespread issue with ethanol-based gasoline.

When the engine isn’t getting fuel due to a clogged carburetor, the solution is to take it apart, clean it, and then reinstall it.

Verify that fuel is reaching the carburetor before assuming it is the source of the problem. If you aren’t, perhaps the fuel filter, fuel lines, or fuel pump are restricting fuel flow.

Carefully spray carburetor cleaner into the intake after removing the air filter.

The carburetor is likely to be at fault if the mower starts and runs normally while consuming the carburetor cleaner but suddenly stops working.

You can attempt to clean the Simplicity carburetor if you are mechanically minded. If you don’t feel comfortable cleaning or replacing the carburetor on your lawn mower, a repair shop can help.

Having Trouble With Your Simplicity Mower’s Gas Cap

Gas cap vents Simplicity mower gas tank. Breaking the cap or blocking the vent prevents air from escaping the gasoline tank, creating a vacuum.

It is the vacuum created by this that prevents fuel from escaping the tank and going to the carburetor. If your mower starts up, runs for a time, and then dies, and you can’t think of why, the fuel cap may be the problem.

Loosening the gasoline cap and letting air into the tank is a good technique to determine if the problem lies with the cap. Then, turn on the mower and let it run.

Try to recreate the issue by running the mower with a tightened fuel cap if the engine starts and runs normally. If the mower sputters and quits again, and won’t start unless you let air into the gasoline tank, the fuel cap is probably broken.

FIX: Get a new Simplicity fuel cap to swap out for the old one.

Simplicity Lawnmower Air Filter Clogged

A clogged air filter is all it takes for your Simplicity to stop down. In order for your engine to run well, you need to make sure it gets plenty of fresh air.

Engine overheating can occur if the air filter is clogged with particles like grass and dirt.

If you continue to mow with a dirty air filter, your mower may not only stop working, but the engine may be severely damaged as well. Keeping your engine’s air filter clean will help you avoid costly repairs or replacement down the line.

Avoid knocking loose dirt into the air intake when you pull the air filter out of its housing. To remove debris from a paper air filter, tap it against a hard surface.

Make sure the air filter lets light through by holding it up to a light. If you can still see light through the filter, it signifies that air is getting through.

If the air filter is black in color, broken, or if you can’t see light through the paper, it needs to be replaced.

Use a solution of mild detergent and water to clean a foam pre-filter. Once the primary paper filter has dried, install the pre-filter on top of it.

Some models of Simplicity lawn mowers call for a specific type of air filter. See this article on the many types of air filters for information on how to clean them.

Simplicity Lawnmower’s Damaged or Soiled Cooling Fins

Filth and grease can accumulate on cooling fins. If the fins are broken or clogged with debris, the airflow needed to keep the engine cool will be restricted.

Take off the top of the engine and clean the radiator fins. Fix the fins that are broken. Make sure the heat shield is fastened properly.

Removing the Simplicity Mower’s Dirty Spark Plug

Intermittent spark from a fouled spark plug might be the death knell for a lawnmower. Take out the plug and have a look at it.

The solution is to change out any spark plugs that are extremely worn or broken. If it’s in decent shape and only slightly dusty, a quick scrub with a tiny wire brush should have it ready for reuse.

If my lawnmower is having issues, I always check the spark plug first. When the mower’s spark plug needs replacing, it won’t break the bank.

Check that the spark plug wire is properly attached and that the space between the electrodes is correct. Both of these can stop the mower from functioning as well.

Causes of a Faulty Ignition Coil in a Simplicity Mower

As the temperature rises, the ignition coil in your lawnmower may malfunction and the engine may shut off. It’s possible for the coil’s windings to come unwound and cause a short.

If the ignition coil is malfunctioning, the spark plug will not receive a high enough voltage to ignite.

The solution is to use high-quality spark plugs. If you suspect a break in continuity and want to check your ignition coil, use an ohmmeter. If your ignition coil is malfunctioning, you should replace it.

The Oil Level in Your Simplicity Mower: Too Much or Too Little

Over-oiling the engine of a Simplicity lawn mower will cause it to die in the middle of cutting the grass. Because of the smoke, your engine may have to hunt for fresh air elsewhere.

Excess oil in a lawnmower engine can create serious problems, including engine failure and the need for a replacement unit.

If you don’t put enough oil in your Simplicity mower’s engine, it will overheat and die from the extra friction.

The ANSWER is to change the oil in the engine as per Simplicity’s instructions. Maintain proper oil fill levels at all times.

Simplicity Mower with Plugged Mower Deck and Unsharpened Blades

If the cutting deck of your Simplicity mower is clogged with debris or if the blades wear out, your engine will have to work harder than necessary.

If there is debris in the path of your blades, your engine may have to work more to propel the aircraft. Causes overheating and possible shutdown. If your mower deck is already clogged up, having dull blades is going to make things a lot worse for you.

Check for cracks or other damage on the mower deck as a possible solution. Clean the deck and sharpen the shears by scraping the surface. When mowing grass, always use the highest possible speed on your mower. Do not attempt to trim wet grass.