14 Reasons Your Ferris Lawn Mower Won’t Start (FIXED!)

A Ferris mower that won’t start can be frustrating especially when you don’t have a lot of time to complete your lawn care projects each week.

A Ferris mower won’t start when it can’t get the air, fuel, and spark required for your engine to run.

This can be due to old fuel; clogged fuel components; dirty carburetor; plugged air filter; bad spark plug, ignition switch, or ignition coil; bad battery; faulty charging system; or bad fuel cap.

Take all safety precautions outlined in your Ferris owner’s manual. This includes removing the ignition key, unplugging the spark plug wires, and setting the parking brake.

This article addresses gas-powered Ferris lawn mowers. If you have starting problems with a diesel Ferris mower, read my guide Reasons a Diesel Lawn Mower Won’t Start.

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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.

Reasons Your Ferris Mower Won’t Start

Fuel Tank is Empty

Of course, you know a Ferris lawn mower requires fuel to run. I only mention it in my list because, when you are frustrated, sometimes the simple things are missed.

You may have just forgotten to refill the tank or you may have developed a fuel leak and are going through fuel quicker than normal.

Solution: Check the fuel tank level and make sure you haven’t developed any leaks in the fuel system. Fill your fuel tank with fresh fuel.

Old Fuel

Gasoline can cause problems with your fuel system and engine. Using the right fuel and not allowing it to sit around for long periods of time will help reduce the damaging effects on the fuel system.

Gas for a Ferris Lawn Mower

Most lawn mowers Ferris offers in their product lineup are gas-powered mowers. A Ferris mower requires unleaded gasoline with a minimum 87-octane rating and a maximum of 10% ethanol content. Avoid using fuels with a higher concentration of ethanol.

Gas that has been sitting in your mower can begin to break down and lose its effectiveness as quickly as 30 days after purchase. When gas begins to break down, the ethanol and moisture it attracts will separate from the gasoline and sink to the bottom of the fuel tank.

This ethanol and moisture solution can degrade the fuel system; gum up and cause fuel blockages, and cause your engine to run hot.

These are a few reasons ethanol is not good for the small engine in your Ferris mower. I share more about the effects of ethanol along with best practices to care for the fuel in this guide.

Use Fresh Fuel in a Ferris Mower

Only use fresh fuel in your Ferris lawn mower. If you are unable to use your fuel within 30 days, add a fuel additive like Sea Foam to your fuel to stabilize it and reduce moisture. Read more about the advantages of using Sea Foam in your Ferris mower here.

Solution: When you have old fuel in your mower, drain the fuel tank using a fuel siphon. Add fresh fuel that includes a fuel additive to stabilize and clean your fuel system.

Fuel Cap Won’t Vent

The fuel cap used on your Ferris mower is designed to vent. Without this vent to allow air to pass through the cap, the fuel tank will act like a vacuum preventing fuel from leaving the fuel tank.

Remove the fuel cap and start your mower. If it starts and runs, reinstall the fuel cap and continue to allow your mower to run for a while. If it shuts down, you may have a plugged fuel cap.

Solution: Replace your fuel cap with a new Ferris fuel cap. You can try to clean your cap to get it to vent first. If that doesn’t work, you must buy a new cap.

Bad Spark Plug or Loose Connection

A fouled spark plug will cause your gas-powered mower not to start. Remove your spark plug and remove the dirt from the tip. If it appears very dark or your plug has a burnt electrode or broken porcelain insulator, you must replace your spark plug.

Spark plug wires that are not securely attached or a plug that isn’t gapped correctly can also contribute to your starting problem.

Solution: Remove your spark plug and inspect it for signs of carbon buildup or a cracked porcelain insulator. Replace with a new spark plug(s). Make sure it is correctly gapped and the spark plug wires are secure.

Plugged Air Filter

Your Ferris mower requires clean air to start and run. Operating your mower kicks up a lot of grass and dirt into the air. The filter prevents these items from entering the engine.

When the filter isn’t regularly replaced and cleaned, it can become so plugged that the mower will not start because it can’t get air.

Running your Ferris with a dirty air filter or no filter at all poses a significant risk of engine damage including overheating. This damage can result in a costly repair or even having to replace your engine.

Spending a little money and taking some time to keep your filter clean is a small price to pay to help protect your mower.

Solution: I recommend starting each mowing season with a new air filter. Keep your air filter in good condition by regularly checking and cleaning it throughout the mowing season. Check it more frequently when you are mowing in dry dusty conditions.

Steps to clean a Ferris mower air filter:

• Remove the air filter from the air filter housing.
• Wipe out any dirt remaining in the housing with a dry clean rag. Don’t allow dirt to fall into the air intake.
• Tap your air filter against a solid surface. Knock as much dirt out of the filter as you can get loose. Don’t use compressed air to clean your filter as this will damage a filter.
• Check for light shining through the paper filter element by holding it up to a light source.
• If you can see light through the paper, reuse the air filter. If you can’t, replace the filter with a new one.
• Install your air filter in the housing and reattach the air filter housing cover.

Clogged Fuel Filter

A fuel filter is used on your Ferris mower to strain the fuel after it leaves the fuel tank. This is to prevent dirt and other particles from entering the fuel system.

When dirt builds up in the filter, it will not allow fuel to pass through the filter so your mower won’t start.

Solution: A clogged fuel filter must be replaced with a new one. When installing a new filter, make sure the arrow on the side of the filter is pointed in the direction of the fuel flow. The arrow should be pointed toward the carburetor and away from the fuel tank.

Blockage in Your Fuel Line  

You can develop restrictions on the fuel lines. This is often the result of running old fuel through your Ferris mower. Gummy deposits are left behind and can clog the fuel lines restricting fuel flow. This will result in having starting and running problems in your mower.

To identify a blockage in a fuel line, you will need to start and stop fuel flow while checking each fuel line section. Use the fuel shut-off valve located at the bottom of your fuel tank or pinch pliers to crimp the fuel line to start and stop the flow.

With your fuel flow stopped, remove the end of a section of the fuel hose furthest from the fuel tank and place it into a container.

Start your fuel flow and check the fuel coming out of the hose and into the container. Make sure the container is placed lower than the fuel tank. Fuel cannot flow uphill without the assistance of a pump.

Solution: Once you find a clogged line, you need to remove the blockage. Do this by removing the line from your Ferris. Spray carburetor cleaner into the line to help loosen the blockage.

Then use compressed air to blow air into the line to remove the blockage. Repeat this process until the clog is removed.

If you are unable to dislodge the clog, you will need to replace your fuel line. You can purchase a mower fuel line at your local hardware store or online. I do recommend replacing your fuel lines, even if you don’t find a clog in them if the fuel lines are dry and beginning to crack.

Bad Fuel Pump on a Ferris Mower

A fuel pump can fail over time. Old gas sitting in your fuel pump can degrade it causing it to fail. The fuel pump will no longer be able to build pressure and push fuel to the carburetor causing your Ferris to not get fuel.

Check for leaks on your fuel pump. If you don’t find a leak, you will need to perform a couple of tests to make sure your fuel pump is operating properly.

To do this, first, verify you are getting fuel to the pump by using your fuel shut-off valve or pinching pliers to crimp the fuel line to stop fuel flow. You may have already completed this when checking for fuel line blockages.

Once you have verified you are getting flow to the pump, check to make sure fuel is being pumped out of the pump. Do this by stopping fuel flow, disconnecting the fuel hose from the carburetor, and placing it in a container.

Start your fuel flow and start your mower. Watch the fuel output coming out of the hose. You are watching for a constant or pulsating fuel flow.

Solution: Replace the fuel pump on your Ferris lawn mower if you are not receiving a constant or pulsating flow out of the pump.

Dirty Carburetor

It is common for a carburetor in your Ferris lawn mower to become dirty and clogged from running old fuel and fuels containing ethanol. The function of your carburetor is to regulate the mixture of gas and air required to create combustion in the engine’s cylinder.

When your carburetor is gummed up, your engine won’t get the fuel and air it needs to start. A dirty carburetor will need to be cleaned and any failed components must be replaced.

Solution: If you are a little mechanical you should be able to handle disassembling the small parts in your carburetor to clean your Ferris lawn mower’s carburetor.

If you are unsure about cleaning your own carburetor, you can have your local small engine mechanic clean your carburetor or you can replace it with a new carburetor.

Clean the carburetor by taking it apart and using carb cleaner to clean the carburetor including the float bowl and needle. You can find steps for cleaning your carburetor here. If your carburetor is too dirty to clean adequately, you should replace it.

Bad Battery, Loose Cables, or Corroded Terminals

Your Ferris will not start with a bad battery that won’t charge or fails to hold a charge. Loose cables or corroded terminals can also contribute to staring problems. Confirm your battery terminals are not corroded and are attached securely to the battery.

Solution: Clean corroded terminals in a baking soda solution containing 2 cups of water and 3 rounded tablespoons of baking soda. Use a wire brush to scrub the terminals clean.

Test your battery with a multimeter. You need a reading of about 12.7 volts. Place on a charger to charge your battery if your reading is less than this.

Read more about the steps and items needed to charge your battery here. If your Ferris battery does not hold a charge, you will need to replace it with a new battery. 

Bad Safety Switch

Your Ferris lawn mower uses several safety switches designed to keep the operator safe. The manufacturer installs safety switches to prevent your mower from starting without your parking brake being engaged.

It also has a safety switch that disengages your mower deck and shuts off your mower if it no longer senses the operator is present. Consult your owner’s manual for additional safety switches on your Ferris mower. When these switches fail, your Ferris mower will fail to start.

Solution: Test a Ferris switch using a multimeter. You can temporarily bypass the safety switch to identify a bad switch but only do this for troubleshooting purposes.

Never operate a mower without the safety switch. Never run a mower when a safety switch is bypassed. A safety switch can save you from serious injury and you never know when you’re going to need it.

Faulty Ignition Switch or Ignition Coil 

You insert the key into your ignition switch and turn it only to find your Ferris doesn’t start or even turn over. The ignition switch or ignition coil could be the problem.

Solution: You can use a multimeter to test the ignition switch. Replace the switch if bad. After you have checked your spark plug is working, check the continuity of your ignition coil using a multimeter. Replace the ignition coil if you find a break in the continuity.  

Faulty Charging System

While the charging system isn’t the main reason your Ferris mower won’t start, it can contribute to a weak battery that prevents the mower from starting.

When the charging system fails to charge the battery, the battery may not be able to start the mower the next time you go to use it. 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: Have your local Ferris dealership or lawn mower small engine repair shop check the charging system to isolate the problem. If you don’t have experience with charging systems, you will most likely just be replacing electrical items until you find one that works.

This can get very expensive because most parts stores won’t let you return electrical parts if you find a part your purchased doesn’t resolve your starting problem.

Incorrect Operating Procedure  

Ferris implements safety precautions with their lawn mowers that require certain steps to be followed when starting and operating the lawn mower.

Solution: Refer to your Ferris operating manual to ensure you are operating your lawn mower correctly, so you don’t set off the safety features that shut off your lawn mower.