Table of Contents
Five Reasons Your Lawn Mower Won’t Start
How to Start an Old Lawnmower
Why Is My Lawnmower Turning Over But Not Starting?
Should I Buy a New Lawnmower?
Lawn Mower Not Starting Bottom Line
Five Reasons Your Lawn Mower Won’t Start
- Low Fuel
- Bad Spark Plugs
- Clogged Carburetor
- Broken Clutch
- Broken Gears
1. Low Fuel
A common reason why a lawn mower won't start is low fuel. While that might sound a bit too obvious, low fuel could be the reason your lawn mower won’t start, especially if you had previously used your mower for an extended period without refueling. In some cases, it might be that your tank has old fuel. Old gasoline loses its potency, so it won’t be able to combust. The result is that your engine won’t start. So the first thing you should do is make sure you have enough fuel and that it is not too old.
2. Bad Spark Plugs
A bad spark plug is another common reason why your lawn mower won't start. The spark plug is the component of your engine that creates the spark which ignites the gasoline. If you have the user manual, look up where the spark plugs are located. Make sure you handle the spark plugs carefully. You can buy a special solution from a hardware store to clean your spark plug from any moisture or grease. After doing that, try to start the lawnmower again. If that did not fix the problem, then you might need to buy a new spark plug. Make sure that you find one that is compatible with the type of engine that you have. Or else it will not work and could cause more damage. Your user manual should specify which kinds of plugs are compatible with your mower.
3. Clogged Carburetor
Another common issue that can cause a lawn mower to not start or to start and then die is a clogged carburetor. If your carburetor is dirty your lawnmower might start then die, or it might not start up at all. The carburetor mixes the fuel with air so that it can combust properly. If your engine does not get the right fuel/air mixture, then it cannot ignite, and your mower will not work. So we recommend checking the filter in your carburetor. The most common culprit is the air filter. Leftover gas can condense and solidify in the filter, so it is unable to pull in air. If the air filter is dirty, then the carburetor will not be able to draw air into the engine. It could also be that your carburetor is not attached properly and is not sealed, so air is leaking out after it is drawn in.
4. Broken Clutch
If your lawnmower starts but the blades are not working, then the problem could be your clutch. The clutch is the thing that diverts power from the engine to drive the blades. Without a working clutch, you won’t be able to work the blades properly. You can repair the clutch yourself, or you can get a professional to help. Unless you have previous experience working with lawnmowers, we would recommend getting a professional to fix it up and install a new piece.
5. Broken Gears
Broken gears can also be the cause of your lawn mower not starting, but this isn't that common. If you have checked all the other issues on this list but have had no luck, then the next thing to check is the gears. If your mower motor is rotating, but the engine is not working, then it could be a problem with bad gears. You can tell if the gears are busted if there is a slow response from the operating button. If your gears are the culprit, then we recommend getting a professional’s help to fix them. You can do this on your own, but we would not recommend that unless you have previous experience fixing lawnmowers.
How to Start an Old Lawnmower
- Prime the Engine: If your lawnmower has a primer bulb, press it several times to draw fuel into the carburetor.
- Set the Throttle: Move the throttle lever to the “start” or “fast” position.
- Engage the Choke: If your mower has a choke, set it to the "choke" or "start" position. This enriches the fuel mixture for starting.
- Slowly Pull the Cord: Gently pull the starter cord until you feel resistance, then give it a quick, strong pull.
- Repeat if Necessary: If the engine doesn’t start, repeat the priming and pulling process. Avoid pulling the cord repeatedly without a break to prevent flooding the engine.
If it doesn’t start after several attempts:
- Check Fuel Delivery: Ensure fuel is reaching the carburetor. You might need to clean the carburetor if it’s clogged.
- Check the Spark Plug: Verify it’s sparking. If not, it might need replacement, or there could be an issue with the ignition system.
- Inspect the Air Filter: Ensure it’s clean and does not restrict airflow.
- Review the Safety Mechanisms: Ensure all safety interlocks are engaged (e.g., the handle lever is pressed).
If it has been a long time since you last used your mower, it might take a bit to warm it up. Most of the time, when you store a lawnmower for a long time, moisture will build up in the fuel tank. Water in the tank dilutes the fuel and can also make the spark plugs not work properly. So if you are just using your lawnmower after a long hiatus, we recommend taking out the fuel tank and trying to get rid of any excess moisture in it.
Why Is My Lawnmower Turning Over But Not Starting?
The most common reasons for this are low fuel, a broken gas valve, or a bad choke fault. A broker spark plug could also be the culprit. You may also have to change the fuel pump if it does not get fuel to the ignition system. Another potential issue could be a blocked fuel line, which would hinder the flow of gasoline to the engine. If the air filter is clogged, it can restrict airflow and make starting difficult.
Should I Buy a New Lawnmower?
Before buying a new one, compare the cost of repairing the current lawnmower to the cost of buying a new one. If the repairs are minor and inexpensive, it might be worth fixing. You should also consider the overall condition of the lawnmower. If it has multiple issues or shows significant wear and tear, replacing it might be more practical. However, a clogged air filter or fuel line shouldn’t require you to purchase a new lawnmower because you can easily fix these issues.
Lawn Mower Not Starting Bottom Line
Without a doubt, your lawnmower not starting is a frustrating situation. Your first instinct is probably to take it in to get service. But before doing that, you should try to figure out the problem on your own. Oftentimes you can fix the issue and get the lawnmower to start again, saving yourself a good bit of money. You can usually troubleshoot common issues, such as a clogged fuel line or a clogged carburetor at home. However, if your mower has a broken clutch or broken gears, then you can consider getting it professionally fixed.