No matter what brand lawn mower or type of lawn mower you own you are bound to run into problems sooner or later. That’s because every mechanical piece of equipment is going to experience failure with time due to wearing and damage caused by normal usage or lack of maintenance.
A Yard Machines lawn mower won’t start when there is a lack of fuel, lack of air, or insufficient spark. This may be due to old gasoline; a dirty carburetor; a clogged fuel line; a bad fuel pump, spark plug, switch, or battery; a plugged air filter or fuel filter; or a faulty ignition coil or starter solenoid.
Follow all safety precautions listed in the owner’s manual for your Yard Machines lawn mower to avoid injury.
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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.
This is Why Your Yard Machines Lawn Mower Won’t Start
Lack of Gas
I’m sure you know gas is required for a gas-powered lawn mower to start and run. I mention it only to serve as a reminder in case you skip this obvious item out of frustration.
Solution: Fill your gas-powered Yard Machines mower with fresh gasoline that has an octane rating of 87 or higher and an ethanol level of 10% or less.
If your lawn mower uses a 2-cycle engine, you must add a 2-cycle premium oil to the gas. Read more about the best type of gas to use in the guide “This is the Type of Gas Lawn Mower Use“.
Bad or Old Fuel
It not only matters what type of gas you run through your Yard Machines mower, but also how quickly you consume it. Old gas breaks down causing corrosion and restrictions in the fuel system.
Always use fresh gasoline and consume it within 30 days of purchase. If you are unable to use fuel this quickly, add a fuel additive to stabilize the gas so the shelf life lasts a little longer to combat the negative effects of ethanol.
Most gasoline includes ethanol, an environmentally-friendly alternative fuel. While ethanol is okay to run in most vehicles, it can be harmful to the small engines run in Yard Machines mowers.
Ethanol attracts moisture to the fuel that leaves behind gummy deposits and is corrosive to the fuel system. This ethanol and water mixture will also separate from the gasoline over time which can potentially damage the engine because this mixture will burn hot.
This is why you must not run any fuels through your lawn mower that include more than a 10% ethanol content. The less ethanol in your fuel, the better for the engine.
Yard Machines lawn mowers require unleaded gasoline with a minimum octane rating of 87 and a maximum ethanol content of 10%.
Straight gas is used in a mower with a 4-stage engine, while a gas and oil mix is used in a 2-cycle engine. If you are unsure of the type of engine your Yard Machines mower uses, refer to your operator’s manual.
- 4-stage (4-cycle) Yard Machines engine:
A 4-stage engine will have separate fill ports, one for engine oil and one for gasoline. Fill the fuel tank with fresh unleaded gasoline. - 2-cycle Yard Machine engine:
Some Yard Machine lawn mowers will use a 2-cycle engine. This type of engine will have one fill port for a gas and oil mix.
Yard Machine lawn mowers with 2-cycle engines require a gas-to-oil mix of 40:1 for mowers manufactured after 2002. Prior to this year, use a gas-to-oil mix of 32:1.
Never use straight gas through a 2-cycle engine as this will most likely ruin your engine. Use a good 2-cycle engine oil mixed with gasoline. 2-cycle engine oil is different than engine oil.
Solution: Remove the old fuel using a fuel siphon and add fresh fuel. Add a fuel additive like Sea Foam Motor Treatment to stabilize the gas, clean the fuel system and reduce moisture. Read more about why I use Sea Foam in my lawn mower here.
Bad Spark Plug or Loose Connection
A lawn mower may not start or may begin to run sluggishly when the spark plug is dirty, damaged, or wet. If it isn’t securely attached to the spark plug wire or gapped correctly, your mower can also experience starting problems.
Solution: Remove the spark plug and inspect it for signs of carbon buildup or damage. This may be a dark tip, burnt electrode, or broken porcelain.
You will need to replace a damaged spark plug or one that is excessively dirty. If the plug is in good condition and only a little dirty, you can use a wire brush to clean the spark plug.
I prefer to replace the spark plug with a new one because it is a crucial component to a good running mower Ma It’s also an inexpensive part.
Make sure the spark plug is gapped according to the engine manufacturer’s specifications. Install the spark plug and securely attach the spark plug wire.
Plugged Air Filter
Another very important maintenance part that needs to be kept clean or replaced regularly is the air filter. The air filter prevents dust and debris from entering the air intake and wearing the engine.
When the filter isn’t regularly cleaned, it can become plugged so a sufficient amount of airflow isn’t able to get to the engine.
This will not only cause a mower’s running and starting issue, but it will also cause a Yard Machine to overheat resulting in potential engine damage.
Replacing your air filter annually and cleaning it several times during the lawn mowing season will help protect your engine and allow it to run at its best.
Solution: Remove your air filter and inspect it. Clean the filter or replace it if necessary using the following steps:
Clean a Yard Machines paper air filter:
- Remove the air filter housing cover.
- Remove the air filter being careful not to allow dirt to fall into the air intake.
- Wipe out any dirt that remains in the housing.
- Tap the plastic or rubber part of the filter against a hard surface to loosen the dirt so it falls out of the filter.
- Once you have removed as much dirt as possible, hold the filter up to a light source. If you can see light through the paper filter, reuse the filter. If you can’t see light or if it is covered in oil, replace the air filter.
- Install either a clean reusable filter or a new filter.
- Reattach the air filter cover.
Clean a Yard Machines foam air filter:
- Remove the air filter housing cover.
- Remove the air filter being careful not to allow dirt to fall into the air intake.
- Wipe out any dirt that remains in the housing.
- Reuse the filter if it is in good condition and not brittle, forming dark spots, or has tears in the filter. Purchase a new foam air filter if you find any of these conditions.
- Wash a filter that is able to be reused. Use mild dish soap and water to remove dirt. Rinse until clear.
- Lay flat to dry.
- Once completely dry, coat with a foam filter oil and replace in the filter housing.
- Reattach the cover.
Plugged Fuel Filter
A fuel filter is used on your Yard Machines lawn mower to keep dirt out of the fuel system. The inline fuel filter is placed between the fuel lines to filter fuel as it comes out of the tank.
When the filter isn’t changed regularly, the filter will become plugged keeping fuel from passing through the filter. A lack of fuel will cause your lawn mower to fail to start.
Solution: If you are not getting fuel flowing through the fuel filter, replace the filter. You will find an arrow on the new filter that must be installed with the arrow pointing in the direction of the fuel flow.
Clogged Fuel Line
The sticky residue left behind by old fuel can clog the fuel lines. In order to identify a clogged fuel line, shut off the fuel supply by placing the fuel shut-off valve in the off position. You can also use hose pinch pliers if your mower doesn’t have a valve.
Identify a section of the fuel line to check for a clog. Remove the end furthest from the fuel tank and place it in a container. Make sure this container is placed lower than the fuel tank because fuel cannot run uphill with the assistance of a fuel pump.
Start the fuel flow and watch the fuel flow out of the line and into the container. If you aren’t getting sufficient flow, you will need to remove the clog or replace the fuel line.
Solution: Once you have found a restriction in a fuel line, shut off the fuel supply and remove the section of the fuel hose from your Yard Machines mower.
Spray carburetor cleaner into the tube to loosen the clog. Blow compressed air into the line until the restriction has been removed.
Repeat spraying carburetor cleaner and blowing compressed air as necessary. Once the clog is removed, reinstall the fuel line onto your mower.
When you are unable to remove the clog, replace the fuel line with a new section of the fuel line of the same diameter and length.
Bad Fuel Pump
The fuel pump exists to pump fuel to the carburetor when then the fuel tank sits lower than the carburetor. The pump is needed to push fuel up to the carburetor. Not all mowers will require a fuel pump.
A fuel pump, just like any other mechanical part, can fail over time. A likely cause is old fuel deteriorating the pump components.
Solution: To identify a failing fuel pump on your Yard Machines mower, first, inspect your vacuum fuel pump for cracks. If you see fuel outside of the fuel pump or cracks in the pump, the pump will need to be replaced.
Use the fuel shut-off valve or pinch pliers to stop and start fuel flow. Stop and start flow to make sure you are getting fuel to the pump.
Once you verify your pump is getting fuel, check to make sure that fuel is being pumped out of the pump in a steady or pulsating flow to identify whether or not your fuel pump is bad.
Clogged & Dirty Carburetor
The function of the carburetor is to regulate the right amount of gas with the right amount of air so your engine can create combustion allowing the mower to start and run. Carburetors can get crusty buildup and gummy deposits from using old fuel containing ethanol.
When the carburetor is no longer to regulate the fuel your engine receives, your Yard Machines engine will run rough or it may not even start at all.
Solution: If you are somewhat mechanical, you can try to clean the carburetor yourself, otherwise bring it to your lawn mower repair shop. You can find steps for cleaning your carburetor in this article.
You may choose to replace the carburetor if it appears to be in very bad condition.
Faulty Gas Cap
The gas cap isn’t just a regular cap. It is designed to vent to allow air to pass through the cap. When the vent becomes plugged, it will fail to start.
This is because the fuel tank will form a vacuum and keep fuel from flowing out of the tank.
You can identify a fuel cap problem by running your mower with and without the cap. If it starts and runs without the fuel cap, but dies after you let your mower run with the fuel cap on for a while, you most likely have a fuel cap vent problem.
Solution: Replace with a new Yard Machines fuel cap.
Bad Battery or Loose Terminals
Yard Machines riding lawn mowers use a battery. If that battery is weak or dead, it will not be able to start the mower. Loose cables and corroded terminals causing a bad connection can also result in starting and running problems.
A push mower or self-propelled mower will use a small battery when it uses an electric start. It will fail to start when the battery is bad or has a weak charge.
Solution: Test your battery with a multimeter. You will want a reading at about 12.7 volts. Charge your battery if it is lower than this level.
You can find more information on charging your battery here. If your battery does not hold a charge, you will need to replace it with a new battery.
Bad Safety Switch
Your lawn mower may use several safety switches in its operator’s presence control system. The switches are designed to kill the engine when the operator leaves the seat.
A faulty switch may not recognize when the operator is in or out of the seat on a riding mower or securely depressing the safety bar on a walk-behind mower.
Solution: You can temporarily bypass the safety switch to identify a bad switch. Do not operate a Yard Machines mower without the safety switch installed for your safety.
Always have safety switches installed and working on your equipment. Replace a bad switch.
Bad Ignition Switch
Some Yard Machines mowers have a key switch. You insert the key into your ignition switch and turn it only to find nothing happens. Your mower does not start.
The ignition switch can be the culprit. You can use a multimeter to test the ignition switch
Solution: Replace the ignition switch if it is bad.
Faulty Ignition Coil
The ignition coil provides voltage to the spark plug so it can fire and start the engine. The engine will not start if the spark plug isn’t able to fire.
Solution: After you verified your spark plug is in good condition, check the continuity of your ignition coil using an ohm meter. Replace the ignition coil if you find a break in the continuity.
Bad Starter Solenoid
A lawn mower solenoid is an electromagnetic switch that is like an on-off switch that actuates the starter motor to turn over the engine. A click or hum when turning your ignition key is an indication to check your solenoid.
Another indication your Yard Machines mower solenoid may be bad is when a wire attached to your solenoid gets hot and begins to smoke or melt.
Solution: Test your Yard Machines solenoid by following the steps here. Replace your solenoid if it is found to be bad.
Faulty Charging System
If your mower runs with a battery (on a riding mower), the charging system can drain the battery and not keep it charged causing your Yard Machines mower to not start.
While the charging system isn’t the main reason your Yard Machines won’t start, it can contribute to a weak battery. The charging system is important to keep your battery charged.
If you find your battery keeps dying and you have to keep placing it on a charger, you may have problems with the charging system. When a component of this system fails, your Yard Machines mower will not start because the battery will not provide enough power.
A bad stator or alternator can be the problem along with several other electrical parts. Read this article to test your charging system here using an ohmmeter.
Solution: If you believe the problem to be in your charging system, I suggest you allow a small engine mechanic to identify which part of the charging system is your problem.
Taking a guess at the problem and throwing parts at your mower can get pretty expensive.
Bad Starter Recoil
If you own a Yard Machines push mower without an electric start, a starter recoil is used to start the engine. The recoil can fail so you are unable to start your mower. A bad pulley; loose or missing spring; or broken clips can keep your recoil from working.
Solution: You can attempt to replace the spring and restring the recoil. If it does not work because other components in your recoil are damaged, such as the clips or the pulley, you are better off just replacing the recoil assembly.
Incorrect Starting & Operating Procedure
A Yard Machines mower has safety features that won’t allow your mower to start unless you follow their starting procedures which include setting your parking brake on a riding mower model.
Make sure the choke setting is correct. The choke restricts airflow allowing more fuel into the cylinder to start a cold engine. You must adjust the choke so it doesn’t continue to restrict airflow once the engine is warm or it will shut down.
Solution: Refer to your Yard Machines operating manual to ensure you are operating your lawn mower correctly so you don’t set off the safety features that won’t allow it to start.