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What should I do when my lawn and garden engine loses power?


Whether you’re trimming around the trees in your yard, cutting firewood or power washing the deck, you count on your lawn & garden equipment to perform each time you start it up. A sudden loss of power makes it difficult for you to continue with your task. The power loss may be continuous or ebb & flow, but the result is the same – an unwelcome interruption to your work.


Like any gas-powered engine, your lawn and garden machine needs three things to power the combustion process

  • Air
  • Fuel
  • Spark to ignite the air/fuel mixture

Incorrect amounts of air or fuel will cause the engine to run sporadically or not at all, as will a weak or improperly timed spark. An engine not getting the right amount of fuel, air or a proper spark will exhibit a loss of power.

Man working on lawn mower engine



Dirty or Clogged Air Filter

The air filter cleans the air before it is drawn into the carburetor and when it does its job properly, may get clogged up with debris removed from the air. A clogged air filter may not allow a sufficient amount of air into the carburetor, reducing the power of the engine. 


Stale Fuel

Bad or dirty fuel will also cause your engine to lose power. Gas will go stale in as few as 30 days, especially fuel mixed with ethanol as it is in many areas. Ethanol attracts moisture over time and the moisture will dilute the gas. Other options include adding a fuel stabilizer to your tank or using canned fuel that contains no ethanol.


Dirty or Clogged Fuel Filter

Your engine’s fuel system has a filter to remove dirt from the fuel before it enters the carburetor. As with the air filter, when the fuel filter does its job, it will become less efficient and may become clogged, restricting fuel flow to the engine.


Tall Grass

Trying to cut grass that is too tall will cause your mower to lose power as it tries to move through the tall grass.


Improper Oil Level

Loss of power may also be caused by an improper level of oil. Too high of a level can lead to froth, introducing air into the lubrication system and reducing the ability of the oil to lubricate the moving parts. Too low of an oil level can also reduce your system’s ability to provide adequate lubrication, increasing friction and putting more of a load on your engine. 


Faulty Spark Plug

A pitted or fouled spark plug will cause inconsistent ignition, and fuel, carbon, dirt and oil on the plug electrodes will also result in an inconsistent spark and loss of power.



Change air filter if it’s clogged or dirty.


Replace fouled or dirty spark plug.


Unclog or replace gas cap if air vent is blocked.


Replace dirty or clogged fuel filter.


Replace old gas with fresh gas (properly dispose of old gas).


Check oil level and add if low.


Adjust cutting height of mower before cutting tall grass.

If none of these suggestions restores power to your engine, then it’s time to call on a professional mechanic who specializes in small engines. 

Learn more about lawn & garden maintenance products, find your part, or find where to buy your part today.

The content contained in this article is for informational purposes only and should not be used in lieu of seeking professional advice from a certified technician or mechanic. We encourage you to consult with a certified technician or mechanic if you have specific questions or concerns relating to any of the topics covered herein. Under no circumstances will we be liable for any loss or damage caused by your reliance on any content.

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