You may have a Toro Recycler, TimeMaster, or even one of those Guaranteed to Start models. No matter what type of push mower you buy or the kind of engine used on the mower, it’s highly likely you’re going to eventually have a starting issue.
The most likely reasons a Toro push mower won’t start are a dirty carburetor, clogged air filter, dirty spark plug, bad fuel cap, clogged fuel filter, sheared flywheel key, and old fuel.
I’ll go over more reasons for your mower issue below. Just make sure you take all safety precautions including removing the spark plug when performing repairs.
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.
15 Reasons Your Toro Push Mower Won’t Start
1. No Fuel
Your mower won’t start without sufficient gas in the tank. (Of course, you already know this.) When this happens, check to see if you have a fuel leak and that’s why you’re running out of gas sooner than you thought.
SOLUTION: Fill your gas-powered 4-cycle push mower with gasoline that has an octane rating of 87 or higher and an ethanol level no greater than 10%.
An older Toro push mower with a 2-cycle engine will require a gas and oil fuel mixture. You can read more about gas for 4-cycle and 2-cycle push mowers here.
2. Bad or Old Gas
Gas can begin to break down and become less effective as soon as 30 days after you purchase the fuel. The sticky substance left behind by ethanol and moisture in the fuel can begin clogging your fuel system including the fuel lines, fuel filter, and carburetor.
A quick way to determine the gas in your Toro fuel tank is old is to check its appearance and do a smell test.
Old gas will have a darker yellow appearance. This is very noticeable when you compare it to the color of fresh gas. It will also have a strong pungent odor.
Here are a few tips for selecting and caring for your gas:
- Only use fresh fuel with a minimum 87-octane rating.
- Don’t use gas that contains more than 10% ethanol.
- Store gas in a sealed gas container in a cool dry location. Gas attracts moisture from the air.
- Consume fuel within 30 days to minimize the effects of old fuel.
- Mix fresh fuel with a fuel stabilizer to keep fuel stable longer.
SOLUTION: Remove the old fuel. Mix a fuel additive with fresh gas and add it to the fuel tank. I have had good results using a product called Sea Foam Motor Treatment.
It cleans the fuel system, reduces moisture, and stabilizes the fuel. You can read more about why I use Sea Foam here.
3. Bad Fuel Cap
Without a vent in the fuel cap, the tank will act like a vacuum and restrict fuel from flowing through the fuel lines. Old fuel can cause clogging in the vent so air will no longer pass through the cap.
To isolate your cap as being the cause of your starting problem, start and run your mower for a while with the cap off and then with it on to see if your cap affects its running ability.
SOLUTION: You may be able to clean your fuel cap and unclog the vent. If you are unable to remove the clog, replace your cap with a new one.
4. Bad Spark Plug or Loose Connection
A spark plug may no longer work and cause intermittent starting and running issues. The spark plug is responsible for igniting the fuel and air mixture to start the engine and create power to rotate the mower blade.
SOLUTION: Check for a spark using a spark plug tester. If you aren’t getting a good spark, inspect the spark plug wire and spark plug condition.
- Remove the spark plug from the cylinder head and check its condition.
- If it is damaged, extremely dirty, or has burnt electrodes, you need to replace the plug.
- If it’s just a little dirty and in overall good condition, clean it with a wire brush. Be careful not to damage the metal.
- Check the gap and make sure it is to the manufacturer’s specifications.
- Install the good spark plug.
- Securely attach the spark plug wire so it makes a good connection.
5. Faulty Ignition Coil
The ignition coil is responsible for supplying voltage to the spark plug to ignite it. When it fails, the spark plug won’t fire.
Before you check for a bad ignition coil (also referred to as an ignition module), you must make sure the spark plug is good.
SOLUTION: Start by checking the spark plug wire. If it is cracked, worn, or has exposed wires, you should replace the coil. Exposed wires can cause the coil to ground out and fail.
Next, check the continuity of your ignition coil. I like to use a spark tester to verify I am getting spark and the coil is working. You can also use a multimeter. Replace the ignition coil if you find a break in the continuity.
6. Sheared Flywheel Key & Timing Problem
A sheared flywheel key will cause the engine timing to be off so the spark isn’t created at the optimal time to ignite the fuel and air mix. This can affect your Toro’s starting issue.
Check these things that may indicate a sheared flywheel key problem:
- Inspect the mower blade. If the blade is damaged, the impact that caused the damage may have sheared the key. (Remove the spark plug wire when working with the blade).
- Pull the starter rope. A potential sheared key will cause the rope to spring back. It doesn’t allow for a smooth even pull.
SOLUTION: Replace the sheared flywheel key.
7. Clogged Air Filter
A Toro push mower requires clean air to run. The air filter prevents dirt and debris from entering the air intake and contaminating the engine. Dirt in the engine can cause significant engine damage.
Never run your mower without an air filter even if it’s only for a short period of time while you source a new filter.
When an air filter gets clogged so air is no longer able to pass through the filter, your mower won’t start. It is important to regularly check the air filter and keep it clean. By checking, cleaning, and replacing this inexpensive part when needed, you can prevent an expensive engine repair.
SOLUTION: Carefully remove the air filter from the air filter housing so you don’t allow dirt to fall into the air intake. If you find dirt in the housing, wipe it out with a clean cloth. Follow one of the following procedures for your type of air filter:
Clean a PAPER push mower air filter:
- Knock out the excess dirt in the filter by tapping it against a solid surface.
- Hold the filter up to a light source and check for light shining through the paper element.
- Reuse the filter if you can see light pass through the paper. If you cannot, replace your filter with a new air filter.
- Install the air filter and attach the cover.
Clean a FOAM push mower air filter:
- Determine whether you can reuse your filter before cleaning it. If your filter has dark spots or is dry and brittle, replace the filter with a new one.
- If your filter is in good condition, proceed with washing it with mild dish soap and water to remove dirt from the filter.
- Rinse the filter and lay it flat to dry. Placing it outdoors in the sun will speed up the process.
- Once the filter is dry or if you are using a new foam filter, add a foam filter oil to lightly saturate the filter. You don’t want it dripping with oil.
- Install the filter into the housing and attach the cover.
8. Stuck Choke or Incorrect Choke Setting
The choke is used to regulate the amount of air pulled into the intake. You will find a choke plate that is closed to start a cold engine and opened to start a warm engine.
When the choke plate sticks and won’t move to the correct position, the Toro engine won’t start. You’ll find an auto-choke on most current Toro push mowers and a manual choke on older models.
SOLUTION: Remove the air filter so you can see the choke plate. Verify the plate will open and close. If it doesn’t, loosen the stuck choke by lubricating any linkages and choke shaft with carburetor cleaner.
- Manual-choke model
- Move the choke lever to the on position: The choke plate should be closed.
- Move the choke lever to the off position (on some models, this is placing the throttle in the fast throttle position): The choke plate should be open.
- Auto-choke model
- The choke plate should be closed when the engine is cold and moved to the open position when the engine warms.
9. Clogged Fuel Filter
The fuel filter’s function is the strain the fuel coming out of the fuel tank to prevent dirt from entering the fuel system and engine. If your fuel filter is clogged and prevents fuel from passing through it, it must be replaced.
SOLUTION: Replace a plugged fuel filter. You may find your mower uses an inline fuel filter placed between the fuel lines.
If you don’t see one there, you may have a fuel filter inserted into the bottom of the fuel tank. Remove the fuel cap and shine a flashlight to view the bottom of the tank to check for a filter.
A filter at the bottom of the tank requires you to drain the fuel tank. It’s best to use a fuel siphon pump or another method to avoid spillage.
Remove the fuel line from the bottom of the fuel tank and then remove the narrow fuel filter. Replace it with a new clean one.
10. Clogged Fuel Line
A push mower fuel line can become clogged by dirt and the sticky substance left behind by old gasoline. This keeps fuel from getting to your carburetor and to your engine. Read more about identifying a clogged fuel line here.
SOLUTION: Remove the fuel line, spray carburetor cleaner into the tube, and use compressed air to blow air through the tube until the line is free of dirt and gummy residue. Repeat as necessary. Replace the fuel line with a new line when you can’t remove the clog.
11. Dirty Carburetor
Your mower uses a carburetor to regulate the amount of gas mixed with air allowed into the cylinder to form combustion.
The additives added to fuel, including ethanol, can cause gummy substances to form in your carburetor. The substance clogs the small parts in your carburetor restricting fuel.
SOLUTION: If you are somewhat mechanical, you can try to clean the carburetor on your push mower. If you are not, have a local repair shop perform the work.
You may choose to replace the carburetor if it appears to be in very bad condition. Have a small engine repair shop clean the carburetor if you don’t want to attempt the cleaning or rebuilding the carburetor.
12. Bad Toro Safety Switch
The safety switch is designed to kill the engine when the operator is no longer present. If you let go of the bail lever, the engine stops.
A faulty switch may not recognize when the bail lever is engaged to start the Toro mower. Refer to your operator’s manual for other types of safety switches that may be used on your model lawn mower.
SOLUTION: Follow the cable down to the switch to make sure the switch is properly grounded to stop the mower when the bail lever is released.
Make sure it isn’t grounded when the bail lever is pulled against the lever to start and operate your Toro push mower.
Do not operate your mower without the safety switch installed for your safety. Always have safety switches installed and working on your equipment. Replace a bad switch.
13. Bad Recoil
Manual start Toro push mowers utilize a recoil to start the mower. The recoil can break and you are no longer able to start your mower.
SOLUTION: If the rope is no longer wrapped around your recoil, you may be able to restring it to get it working again. You may have a broken pulley, spring, or clips that need to be replaced.
If you find broken parts, you should price out the parts in addition to the whole recoil assembly. It may be more cost-effective to replace your recoil.
14. No Engine Compression
Poor compression will lead to a starting and running issue. It is an indication of an engine problem like head gasket, valve, cylinder wall, or piston ring damage.
A simple check you can do to tell if you are getting any compression is to remove the spark plug wire and slowly turn the blade in reverse to the compression stage. You should feel some resistance indicating there is some compression.
While this is a good initial quick check, it won’t tell you if you have sufficient engine compression. To check compression you’ll have to complete a compression test or a leak-down test.
Note: On engines with an automatic compression release (ACR), it’s best to do a leak-down test unless the manufacturer provides specifications for compression testing an ACR.
Additional Things to Check on an Electric Start Toro Mower
15. Bad Battery or the Wiring is Loose
Push mowers with an electric start require a power source like a battery. Make sure your cables and battery terminals are secure.
Clean any corrosion you find on your terminals using a baking soda solution (2 cups water to 3 heaping tablespoons of baking soda). Once you confirm you have a good connection, continue testing the battery.
SOLUTION: Test your battery with a multimeter. Replace a bad Toro battery.
16. Bad Ignition Switch
Your lawn may have an ignition switch that has failed. If you press the ignition switch and nothing happens, you need to check your switch using a multimeter.
SOLUTION: Replace the ignition switch if it is bad.
17. 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 Toro solenoid may be bad is when a wire attached to your solenoid gets hot and begins to smoke or melt.
SOLUTION: Replace your solenoid/starter if it is found to be bad.
18. Blown Fuse
The fuse is used to protect the electrical system. Check for a blown fuse that can keep your Toro push mower from starting. You will find the fuse near the battery.
SOLUTION: Replace a blown fuse with a fuse that has the same amperage.