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What Should I Do If My powersport Engine Hesitates or Has Poor Acceleration?


When you engage the throttle on your ATV, motorcycle, snowmobile or personal watercraft, you expect your machine to respond by taking off. When your powersport engine hesitates or has poor acceleration, it’s a problem that can leave you stranded on the trail or water.

Many powersport machines are designed for seasonal use, meaning that for part of the year they are in storage. Any engine not used on a regular basis and stored for an extended period of time can experience problems like poor acceleration or hesitation.



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 stall at the most inappropriate times.

Poor acceleration or hesitation may be a sign that your spark plug is worn or dirty or the incorrect type of plug is being used. Examples of poor acceleration include an absence of response or a delayed reaction when you twist the hand throttle or shift the thumb lever.



Improper Spark Plug Type
Spark plugs come in a variety of types for different driving, or riding conditions and the plug in your engine may not suit your type of riding.


Dirty or Worn Spark Plug(s)
Carbon, oil residue and pitting on the spark plug electrodes will cause a weak or inconsistent spark, resulting in poor ignition and poor acceleration. 


Clogged Air Filter
A clogged air filter may not allow a sufficient amount of air into the combustion chamber, making the air/fuel mixture overly rich and causing poor acceleration.


Bad Gas
Bad gas will cause your engine to run erratically. Gas can go stale in as few as 30 days, especially gasoline mixed with ethanol as it is in many areas. Ethanol attracts moisture over time and the moisture will dilute the gas causing your engine to run poorly.


Dirty Carburetor
Bad fuel may also cause harmful gum or varnish deposits to form inside your carburetor restricting or clogging vital carburetor passages and jets, resulting in uneven fuel supply and poor acceleration.



Double check that the correct spark plug is installed.


Replace fouled or dirty spark plug(s).


Change air filter if it’s clogged or dirty.


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


Have carburetor cleaned.


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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