Lawn Mower Won’t Start: Key Things to Know

By PropertyClub Team
Jul 17th 2022
You’ve just taken your lawnmower out of your garage, and when it’s time to start mowing the lawn, it won’t start. It's a common problem to have, but there's often a quick and easy fix if you can diagnose the problem. Some of the most common reasons a lawn mower won't start include low fuel, spark plug issues, a clogged carburetor, a broken clutch, or broken gears.

hash-markTable of Contents

Reasons Your Lawn Mower Won’t Start
How to Start an Old Lawnmower
Why Is My Lawnmower Turning Over But Not Starting?
Lawn Mower Not Starting Bottom Line

hash-markReasons Your Lawn Mower Won’t Start

1. Low Fuel

It might sound a bit too obvious, but 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

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 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

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. 

hash-markHow to Start an Old Lawnmower

If it has been a long time since you last used your mower, it might take a bit to warm them 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. 

hash-markWhy Is My Lawnmower Turning Over But Not Starting?

If you pull the cord and hear your engine turn over, but your mower is 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. 

hash-markLawn Mower Not Starting Bottom Line

Without a doubt, your lawnmower not starting is a frustrating situation. When you notice that your mower isn’t working, your mind will start racing with questions. 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.