Dad's Guide When Your Gas-Powered Lawn Mower Is Not Starting
Maintaining a lush and trimmed lawn can be strenuous and time-consuming. However, when the grass in your yard starts to grow rapidly, you may be compelled to trim your lawn. Nobody wants their yard to look untidy.
Not only is an untidy lawn unsightly, but the long grass can also harbor dangerous pests. That’s why lawnmowers are a necessity. These machines provide an easy way for homeowners to trim their lawns. However, what do you do when your lawn mower is not starting? The sound of your prized trimmer struggling to turn on can make anyone worried.
However, before you panic and rush to the repair shop, you should first identify what the problem is. You may even be able to fix the issue. Continue reading to learn why your lawn mower is hard to start and how to fix these issues.
Safety Tips Before Working on the Lawn Mower
Is your lawn mower hard to start? Before checking your lawn mower for faults, it is essential to follow safety tips to ensure you don’t get hurt. Let’s highlight five safety tips to adhere to before examining your lawn mower.
1. Remove any ignition sources
When working on the tank or fuel lines, stay away from ignition sources like naked flames, cigarettes, sparks, etc. Additionally, make sure there is adequate ventilation to prevent vapor buildup. Don’t leave rags soaked in gas lying around, as they could catch fire.
2. Remove the spark plug or disconnect the lead
If you’re going to be working on the engine’s underside, ensure all the controls are turned off. The spark plug lead should be disconnected, and the engine should be cool. Furthermore, remove the spark plug from the engine before turning the blade for maximum safety.
3. Read the instruction manual
The manufacturer’s instruction manual contains the best way to operate and repair the machine, with helpful safety and maintenance tips. After all, the manufacturer is in the best position to highlight how to safely operate and maintain the machine.
4. Turn off the fuel tap
Consider turning off the machine’s fuel tap especially if the lawn mower is placed on its side or plug side up. Some engines have an overflow in the float bowl, and fuel can leak out through this vent. Also, when the engine is not horizontal, the float may not function properly. This will cause the carburetor to overflow into the engine’s intake manifold. Note that fuel that leaks and touches a hot engine can start a fire. Pay attention to these precautions to ensure there are no injuries.
5. Drain the fuel tank
If your repairs involve turning the machine at a steep angle, draining the machine’s fuel may be necessary. You don’t want fuel leaking through the fuel cap. This will not only waste fuel but also be a possible safety hazard.
Common Reasons Why A Gas-Powered Lawn Mower Is Hard to Start
Here, we’ll discuss seven common causes of your lawn mower not starting. We’ll also outline how to fix these issues so you can turn on your machine and start mowing!
1. Old or bad fuel
Gas can degrade and lose effectiveness as soon as 30 days after purchase. As a result, the sticky residue left by moisture and ethanol can clog the fuel system, including the carburetor, fuel filter, and fuel line. If you’re not going to use the fuel within 30 days, we recommend adding a fuel stabilizer. This will preserve the quality of the fuel and prevent any damaging obstructions.
How to fix it: Drain the old fuel and fill the tank with new fuel. Use a fuel additive to clean and stabilize the fuel system.
2. Faulty Spark Plug or Loose Connections
A faulty spark plug can make your lawn mower hard to start or not start at all. Clean or replace the plug if you notice the tip of the spark plug is very dark in color. This dark color is a result of carbon buildup, which can affect the ignition of the spark plug. In addition, a damaged spark plug with a burnt electrode or a broken porcelain insulator must also be replaced.
We recommend changing the spark plug of your machine to minimize the risk of your machine seizing up when it is needed. Starting issues can also be caused by loose spark plug connections. So, ensure the plug is properly connected before checking and changing the plug.
How to fix it: Remove the spark plug and look for signs of carbon buildup or a cracked porcelain insulator. Then, clean the spark plug with a wire brush or sandpaper. However, if you don’t want to go through this hassle, replace the spark plug with a new one. Ensure that they are gapped properly and that the spark plug wires are correctly connected.
3. Clogged Fuel Filter
A clogged fuel filter could be the reason your lawn mower is not starting. The function of the fuel filter is to “filter” the fuel from the fuel tank to prevent dirt from entering the lawn mower’s engine and fuel system. If the fuel filter is clogged and doesn’t allow fuel to pass through, the machine will not start because it requires a proper supply of fuel to function. Therefore, you need to replace the fuel filter.
How to fix it: Replacing the clogged fuel filter is the solution to this issue. You will find a small arrow on the side of the filter. Install the filter with the arrow pointing in the direction of the fuel flow. In addition, the arrow should point away from the fuel tank and toward the carburetor.
4. Dirty Carburetor
A lawn mower’s carburetor controls the amount of fuel mixed with air that is allowed to combust in the cylinder. Fuel additives, such as ethanol, can cause sticky substances to clog your carburetor. This will restrict the flow of fuel entering the machine’s cylinder and cause difficulty when starting the machine.
We recommend changing the spark plug of your machine to minimize the risk of your machine seizing up when it is needed. Starting issues can also be caused by loose spark plug connections. So, ensure the plug is properly connected before checking and changing the plug.
How to fix it: If you have experience dismantling your mower, you can remove the carburetor and clean it with a compressed air can. However, if you are not sure how to remove or clean your carburetor, you can take your lawn mower to the nearest repair shop. If cleaning the carburetor doesn’t work, you may need to replace it.
5. Clogged Fuel Line
As we mentioned earlier, dirt and sticky substances left behind by old fuel can clog the lawn mower fuel line. This will prevent fuel from entering the engine and carburetor, leading to the machine not coming on or turning off immediately after it comes on.
How to fix it: Detach the fuel line, spray carburetor cleaner into the tube, and use compressed air to blow air into the tube until it is clean of dirt and any residue. If the fuel line can’t be completely cleaned, we recommend replacing it with a new one.
6. Faulty Ignition Switch or Coil
It is not uncommon for lawn mowers to have safety mechanisms such as safety switches built into the system. These safety switches are designed to stop the engine when the operator leaves the machine and the mower deck is engaged
While this mechanism reduces the likelihood of terrible accidents, it can also be the cause of the mower not starting. A faulty switch may fail to detect when the operator is in or out of the seat, resulting in the mower not starting.
How to fix it: If the ignition switch or coil is faulty, replace them.
7. Damaged Safety Switch
It is not uncommon for lawn mowers to have safety mechanisms such as safety switches built into the system. These safety switches are designed to stop the engine when the operator leaves the machine and the mower deck is engaged.
While this mechanism reduces the likelihood of terrible accidents, it can also be the cause of the mower not starting. A faulty switch may fail to detect when the operator is in or out of the seat, resulting in the mower not starting.
How to fix it: First, refer to your machine’s owner’s manual to learn more about the safety mechanism. Fortunately, you can temporarily bypass the safety switches on most lawn mowers to identify if a bad switch is the main culprit. However, ensure you don’t operate the lawn mower without the safety switch installed and operational for your safety.
Read our guide if you’re interested in knowing more reasons why your lawn mower won’t turn over.
Conclusion
We understand it can be frustrating when trimming your yard is hindered by a faulty lawn mower that doesn’t start. That’s why we’ve highlighted the most common causes of this issue. Luckily, you can quickly fix most of these issues.
However, if you’re not confident about fixing the lawn mower by yourself, you can employ the services of an expert repairer. So, check these components on your machine to identify why your lawn mower is not starting, and fix the responsible components so you can give your greens a much-needed trim!
Frequently Asked Questions
1. Why is my lawn mower smoking?
The most likely cause for smoking is excess oil in the engine. Other reasons include a blown head gasket, damaged cylinder or rings, etc. We recommend taking your lawnmower to a repair shop to fix.
2. Why does my lawn mower turn over but not start?
If you start the engine and hear it slowly revving, but the mower eventually does not start, the most common causes are low fuel, improper choke placement, faulty spark plug, or a broken gas valve. Moreover, if the fuel pump is not delivering fuel to the ignition system, the machine may not turn on. Therefore, you may need to repair or replace these components.
Tyronne Finney
Tyronne is a seasoned writer for Dad's mowers. Since finishing his apprenticeship Tyronne has spent the last ten years working in his own small engine repair business. Over his career, Tyronne has seen and repaired and serviced just about every yard tool imaginable.
In the weekend, Tyronne takes time off to spend time with his new daughter.
