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What should I do when my powersport engine loses power?


There is nothing like the freedom you experience when you go for a ride on your motorcycle, ATV, snowmobile or personal watercraft.  Powered by a two-stroke or four-stroke internal combustion engine, nothing is more frustrating than an engine that starts and seems to run fine for a time, but then loses power. The power loss may be continuous or it may come and go. Don’t wait for the loss of power to become permanent; it’s time to figure out what’s causing your engine to lose power.



Just like the gas engine in your car, truck or SUV, your powersport engine needs three things to run properly:

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

If any of these elements are not supplied to the combustion chamber in the proper amounts and at the proper time, your engine will not run as smoothly and may lose power at the most inappropriate times.

The carburetor mixes a proper amount of air and fuel together and directs the mixture into the combustion chamber. Your spark plug then sparks at the right time to ignite the mixture and the explosion applies a driving force to the piston. Incorrect amounts of air or fuel will cause the engine to run poorly, as will a weak spark.


If you’re experiencing a loss of power, you know it can happen at any time without any warning. Loss of power problems can be traced to:


Faulty Spark Plug

A spark plug fouled with fuel, carbon, dirt and oil on the electrodes will result in an inconsistent spark and loss of power.   


Clogged Air Filter

The air filter cleans the air before it is drawn into the carburetor and when it does its job properly, it may get clogged 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 your engine.


Bad Gas

Bad or dirty gas will also cause your engine to lose power. Gas can go stale in as few as 30 days, especially when mixed with ethanol as it is in many areas. Ethanol attracts moisture over time and the moisture will dilute the gas.


Improper Oil Level

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


Vapor Lock

Caused by fuel turning from liquid to vapor in the fuel line, vapor lock usually occurs after traveling at low speeds for long durations while high temperatures, weather and altitude can also play a role.



Replace fouled or dirty spark plugs.


Change air filter if it’s clogged or dirty.


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


Check oil level and add oil as necessary.


Make sure fuel line and tank have minimal exposure to engine and exhaust heat and that all heat shields and insulators are in place. 

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

Learn more about powersport 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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