It does not turn on

It doesn’t matter if you’re mowing your lawn, plowing your garden, or shoveling snow from your driveway with the snow plow, when it’s time to get the job done, nothing is more frustrating than when the machine won’t turn on. The more you pull the starter cord or press the starter button and hear the engine spin without starting, the more frustrating it becomes. The motors of the machines for external use are quite simple, but from time to time, problems will appear that can affect the motor at the time of operation.



Just like in a car, truck or SUV, the engine of outdoor machines needs three things to start and function properly: air, fuel, and a spark to ignite the air / fuel mixture. If any of these demands are not sent to the combustion chamber at the right time and in the right amount, the engine will not start.

The engine has a carburetor that mixes air with fuel and sends the mixture into the engine’s combustion chamber. Once in the combustion chamber, the mixture is ignited by a spark that comes from the spark plug. The explosion applies a force to the piston, which moves the cutter blade.

The engine will not start if the right amount of fuel and air is not sent to the combustion chamber, or if the spark plug does not produce a spark at the correct time to ignite the air / fuel mixture.

What to look for

The motors of outdoor machines are very simple machines and when they do not start, it is likely due to a lack of air, fuel or a good spark. Probable causes of the problem:

  • Dirty or clogged air filter – Before air enters the carburetor, it passes through an air filter to remove dust and dirt. During filtration, the filter can become clogged due to debris coming from the air and may not allow enough air to pass to the carburetor, thus preventing the engine from starting.

  • Dirty or clogged fuel filter: The fuel filter prevents dirt from entering the fuel into the carburetor, and like the air filter, it can become clogged and prevent enough fuel from passing into the combustion chamber by preventing the engine from starting.

  • Defective spark plug – A spark plug that has the electrodes dirty with fuel, carbon, dirt, or oil cannot produce a spark strong enough to ignite the air / fuel mixture, and the engine will not be able to start.

  • Defective Fuel – Ethanol-derived fuel can expire in 30 days or less. As the fuel dissolves, rubber and shellac form, which can clog the fuel lines and carburetor nozzle, and the engine will not be able to start.

  • Fuel Tank Cap – Most fuel caps have an air vent that allows air to enter the fuel tank as fuel is consumed. Sometimes this vent becomes clogged with debris and restricts the flow of fuel to the carburetor.

  • Fuel Lines – Broken or collapsed fuel lines can prevent fuel from entering the engine and prevent the engine from starting.

What to do

On most small industrial engines, the air filter can be accessed and removed without the use of tools. Check the owner’s manual and inspect the air filter; if it is dirty, it must be replaced. Remove and inspect the fuel tank cap and verify that the air vent is not plugged. If it is, the best option is to replace it. Also, if the fuel in the tank is old, it must be disposed of properly and replaced with new fuel. A good tip is to tape the fuel container and write the date it was purchased. Fuel life can be extended by using a fuel stabilizer available at any service station or auto parts store.

If engine parts need to be replaced, such as spark plugs or air filters, get a product from a reputable brand, such as Champion. Make sure you buy genuine parts and not low-budget knockoffs.


Once the engine starts the first time you pull on the belt or press the power button, you’ll be amazed at how quickly it completes tasks.

The content in this article is to be used for informational purposes only and not to substitute for the professional advice of a certified technician. You should consult with a certified technician if you have specific questions or concerns regarding some of the topics discussed here.

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