The lifetime of a typical lawn mower is around 8-10 years. However, people still encounter many issues during this period. It's because lawn mowers and other gardening tools are not used daily.
Still, most of these issues can be resolved with simple fixes, such as checking the spark plug or air filter.
In this article, we'll discuss common issues why your lawn mower does not start. We'll also discuss its repair methods and the differences between electric & petrol mower issues. Lastly, we'll show you when it's time to replace your lawn mower.
Part 1. Common Reasons Your Lawn Mower Won’t Start
Mostly, a Lawn mower won't start due to issues related to the fuel system, spark plug, air filter, battery, safety devices, and grass collection box.
Here are the details of how these issues can prevent your lawn mower from starting.
- Faulty Fuel System: Most Lawn mower fuels lose value after 30 days. Other than that, a clogged carburettor, a dirty fuel filter, and a closed shut-off valve are common causes.
- Issues with Ignition: A damaged ignition coil, dirty spark plug, or corroded ignition wires will disrupt the flow of electricity. It fails to create a spark that ignites the fuel.
- Clogged Air Filter: A clogged air filter will restrict the airflow to the engine. It leads to a fuel-air mixture with excessive fuel and insufficient air for combustion.
- Faulty Electrical connections: Some lawn mowers have electrical systems for starting the devices. Loose connections in the battery terminals or ignition wiring will prevent the flow of electricity.
- Damaged Safety Devices: A malfunctioning safety device can trigger the safety system even when all other components are functioning correctly.
Part 2. How to Troubleshoot a Non-Starting Lawn Mower
You can troubleshoot a non-starting lawn mower by checking the fuel, changing the ignition apparatus, cleaning the air filter, and other simple actions.
Before we take a look at these issues in detail, grab these tools first:
- Spark Plug Wrench.
- Screwdrivers (Flathead and Phillips).
- Adjustable Wrench.
- Fuel Siphon Pump.
- Carburettor Cleaner.
- Safety equipment, such as gloves and Safety Goggles.
- Cleaning tools, such as a wire brush or rags.
- Battery Tester or Multimeter.
1. Examine the Fuel Level & Quality
Open the fuel tank of your lawn mower and examine the level and quality of its fuel.
If the fuel pickup of your lawn mower is not fully submerged, you just need to add more fuel to it. For a quality check, look for the colour, smell, or impurities in the fuel. If the fuel is more than 30 days old, it will appear cloudy, dark, or have a yellowish tint. It will also have a sour or stale odour with many sediments in it.
If you find any of these features, replace the fuel without any second thought. It’s always best to use a fuel with an octane rating of at least 87 RON or less than 10% ethanol content.
2. Check the Fuel Line & Filter
Locate the fuel filter of your lawn mower. This is usually located between the fuel tank and the carburettor. However, if the fuel filter is within the fuel tank, you will need a hook to pull it out.
Check for any debris or dirt in it. There’s a simple way to check if a fuel filter is clogged or not. A good working filter will allow light to pass through it easily. If the light can’t pass, then you need to replace the filter.
Now, look for any cracks or kinks in the fuel line. Blow through it to check for any obstruction. Try to clear any blockage, or you’ll need to replace the line if it’s severe.
3. Check the Spark Plug
First, unplug the spark plug wire to prevent any accidents. Take a spark plug socket and remove the plug gently. Check for any carbon deposit, oil, or cracked insulator of the plug. If there’s any sign of debris, clean it using a cloth dampened with petrol.
You also need to check the spark plug gap. If it’s against the manufacturer’s guidelines, you need to change the plug when a lawn mower won't start.
4. Clean the Air Filter & Carburettor
An air filter housing is mainly located on one side of the engine. Take a screwdriver and unscrew the cover. Gently remove the air filter and look for any debris or damage.
A paper filter can be easily cleaned by tapping on it gently or using a brush. If your lawnmower has a foam filter, wash it thoroughly with soap and water to remove any debris.
You’ll see the opening of the carburettor under the air filter. Spray the carburettor cleaner in these openings and clean them with a fine brush.
5. Look at the Power Supply (for electric start models)
If you have an electric lawn mower, check its battery terminal, battery voltage, or any loose connections.
A white or greenish buildup on the battery terminal is a red flag. You need to clean it with a solution of baking soda & water.
Use a multimeter to check the battery voltage. If it’s less than 12 volts, then recharge or change the battery when the lawn mower does not start. Also, inspect the wiring for any damage or loose connections.
Then remove the fuse from your lawn mower and look at it closely. A broken wire inside it indicates damage, and you need to replace it with a new one.
6. Unclog the Mower Deck
If the starter rope is hard to pull, it indicates that the deck is clogged. Tip the lawn mower on one side so that the carburettor is facing upwards.
Now examine the undersurface closely. If there are grass clippings, leaves, and other debris, remove them with a scraper.
After that, spray it with water to remove other debris. When it has dried, restart the lawn mower.
7. Check the Starter Buttons
If your lawnmower has a key ignition starter, you’ll hear a click when turning the key. If you can’t listen to it, then the solenoid is not working correctly. Replace the starter solenoid when the lawn mower does not start.
For push-button start systems, remove & reinsert the safety key. If the issue was due to a loose connection of this safety key, the lawn mower will start working again.
Part 3. Lawn Mower Won't Start After Winter
The primary reason is fuel degradation and moisture buildup during storage. According to the Outdoor Power Equipment Institute (OPEI), fuel can start to go bad in as little as 30 days.
During winter, the fuel stays in the lawn mower for months. This fuel separates and attracts moisture, especially if the ethanol content is high. The water, in turn, grabs dust particles, which clog the carburettor.
Moreover, the engine oil in the lawn mower thickens over time, and the spark plug also gets corroded.
So the next time you store your lawn mower for winter, drain all the fuel and engine oil from it. After that, run the engine until it stops, burning any remaining fuel.
Part 4. Differences Between Electric and Petrol Mower Issues
Electric lawn mowers mostly have issues related to the power supply system, motor overheating, and cord limitations. On the other hand, petrol lawn mowers face issues such as engine problems, including fuel issues, spark plug malfunctions, or air filter clogs.
Common Issues with Electric Mowers
- Electric mowers can easily overheat if not appropriately handled.
- The length of the cord limits the use of corded electric movers.
- Cordless electric mowers face charging & run-time issues.
- These mowers are more susceptible to water damage than petrol mowers.
Common Issues with Petrol Mowers
- They don’t work at maximum efficiency if the fuel has gone bad or the fuel lines are obstructed.
- The air filter gets clogged easily and requires regular cleaning.
- Lawn mower cranks but wontstart with a faulty spark plug.
- These mowers require frequent oil changes and are susceptible to oil leaks.
- Cleaning the fuel system and carburettor requires skill and takes a considerable amount of time.
Part 5. When to Repair vs Replace Your Lawn Mower
You can go for a repair if you:
- Have a new and well-maintained lawn mower.
- Encounters minor issues like a faulty spark plug or a clogged air filter.
- If the price of repair is less than the cost of a new lawn mower.
- If your lawn mower is under warranty. The repair cost is covered in this case.
The common price of a lawn mower repair:
- The average labour cost of repairing a lawn mower is between £30 & £50 per hour.
- A motor repair will require materials of about £20-£100.
- A rotary pusher repair will need more expensive materials, costing about £80-£500.
However, you need to replace your lawn mower when:
- You have an old lawn mower that requires numerous costly repairs.
- An expert examines your lawn mower and advises you to replace it.
- You do not have the warranty to cover the repair cost.
- You want to enjoy new technologies like self-propulsion, better blade guards, and other advancements.
If you are looking for a new lawn mower, check out the eufy Robot Lawn Mower E15.
eufy Robot Lawn Mower E15 - The Hand-free Option
The eufy E15 is an advanced robot lawn mower for hands-free lawn care. As a robotic mower, it is less likely to have the not-starting issue as long as it is charged.
It only takes 5 minutes to set up the lawn mower, and it will automatically map your lawn without any signal issues. Now you can sit and relax while the eufy E15 do the mowing and trimming for you.
The other interesting features of the eufy E15 are:
- Pure vision FSD technology with high-precision cameras: no wires or RTK station needed.
- Accurate obstacle avoidance with 3D perception system: avoids collisions in the garden.
- A maximum coverage of 800 m² (0.2 Acre).
- GPS tracking to prevent theft.
Conclusion
When the lawn mower does not start, it's due to issues related to the fuel system, spark plug, air filter, or electrical connections. This problem is more common when we take out the lawn mower after the winter season. The petrol mowers mostly have fuel system issues, while electric mowers encounter power supply errors.
You can resolve these issues with simple cleaning or changing the faulty parts. However, if your lawn mower is old and requires costly repair, it's time to get a new lawn mower like the eufy E15.
FAQs
What is the First Thing to Check if a Lawn Mower Won't Start?
The first thing to check if a lawn mower does not start is the fuel supply. If the fuel looks dark and cloudy with a sour odour, you need to remove this old fuel. Use a new one with at least 87 RON and less than 10% ethanol content.
Why is my Lawn Mower Turning Over but not Starting?
When a lawn mower fails to start after turning over, it indicates that issues are related to fuel, spark, or the air filter. It may be due to contaminated fuel, a clogged carburettor, a faulty spark plug, a damaged fuel solenoid, or a dirty air filter.
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