How to Start a Lawn Mower That Has Been Sitting

How to Start a Lawn Mower That Has Been Sitting

A lawn mower is a common tool for keeping your lawn looking its best. One of the most frustrating things that can happen to your mower is that it won’t start after being stored for a while. This could be due to the gasoline evaporating in the carburetor, or something as simple as insufficient compression in the engine’s piston.

Here, are some tips on how to troubleshoot this issue and get your lawn mower running again.

Check Air Filter

If your mower doesn’t start, this is a good place to start. Inspect the air filter, if it’s dirty, it could be causing fuel to leak, which could be the problem. Clean it by hand and use it to check the air pump. If you see air bubbles in the filter or air in the line, you know you need to replace it.

Pull It Apart: If the air filter isn’t the problem, you’ll likely have to take the mower apart. Carefully pull back the grip and exhaust tract and examine the engine. If you can, unscrew the power steering column. The inner workings of the engine will be hot, which means there’s not enough coolant in the system.

Start It Back: Up If all is well, the problem is probably the air filter. Take the mower apart again, this time ensuring the air filter is completely clean.

Adjust the Spark Plug

Although the timing belt is probably your first line of defense when it comes to starting your lawn mower, you may also want to check the timing belt itself. A properly installed timing belt will only allow you to run the engine for a limited amount of time.

If you inspect it, it should be in one continuous motion that doesn’t bind and prevent the engine from running. If your engine still won’t start after checking this component, then you probably need to replace the timing belt. If it is the timing belt, make sure that you replace it with a new one that’s suited for the engine of your lawn mower.

Check the Battery: Having a sluggish lawn mower that won’t start can happen when the battery is severely overcharged.

Recheck the Gasoline Level

When you first get your mower, check the level of gas in the fuel tank. If it’s low, you’ll need to add more. When there’s too much gas in the tank, the engine won’t run. Overcharging the engine will also make the mower won’t run, but it could also be due to a slow or stalling engine.

Plug the Carburetor: If your mower is running fine but just needs a little gas, put it in the stand for a minute or two. This will give you an idea of how much to add. Most small mowers can be refilled from a gasoline container.

Cleaning the Carburetor: Before you start, ensure that you clean out any oils, old gas, or other junk that is in the carburetor. Having this done can make a huge difference in whether or not the carburetor will accept the added fuel you just added.

Add More Fuel

The carburetor in your lawn mower isn’t designed to be used as an air cleaner, so to get it working again, it’s usually a good idea to add some fuel. Check your owner’s manual to see how much gasoline the mower requires, or if it has a switch to turn on the fuel pump.

If you don’t have a manual, check online for instructions on how to add more fuel. You should also check the level of fuel in your fuel tank before adding any fuel. Make Sure Your Piston is Tight. One of the most common issues that can cause a lawn mower to not start is that your piston is too tight.

You should always test this before you use your lawn mower by using a pry bar or ratchet set. Take the lawn mower out of the storage container and run it through the mower start-up sequence.

Compress the Engine with a Tool

There are two types of engines: oil- and gas-fired. Gas-fired engines require compressed air to operate, and when there is not enough, the engine won’t run. When the engine is completely cold and after you’ve been through the compression process, you should be able to start the mower, or you can run it on the battery.

But you can’t rely on the battery alone, as there may be any number of problems with the battery that make it more likely to fail. Check to see if the carburetor has been sitting for too long. Check the dipstick to make sure the jet is in the right place.

Once the carburetor is free from any other contaminants, fill the dipstick with a few drops of gasoline, then turn the engine over and let it run for several minutes.

Reset the Carburetor Float

The carburetor is part of the fuel system. The float controls the position of the fuel in the carburetor. The float is supposed to float the carburetor to the opening of the fuel port. If the float is not working, you can reset it by removing the carburetor oil drain plug.

You can then pour a few drops of engine oil into the float to make it float. Reinsert the drain plug and try starting the engine. If that doesn’t work, you can try pumping the gas a bit. In most cases, when this doesn’t work, the carburetor needs to be cleaned and the float resituated.

You can also use a car shop to check the carburetor and take care of this job. Tune the Drive Type A typical mower’s engine has several types of belts that cause it to move, especially the drive belts.


Either the carburetor has been blown out, the battery needs to be replaced, or it simply needs to be tested. As with anything, let the experts do their job and it will always be the best option.

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