Whether you’re hitting the trail on your ATV, motorcycle or snowmobile or taking on the waves with your personal watercraft, nothing can ruin a day of fun like a powersport engine that stalls. A stalling motor is an unreliable motor; it can leave you stranded on the trail or water. Without power, you may have to wait for someone to tow you and your machine. Don’t wait to get stranded; it’s time to get to the bottom of your stalling problem.
Just like the gas engine in your car, truck or SUV, your powersport engine needs three things to run properly:
- 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.
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.
A stalling engine may or may not give you any warning. You may experience hard starting when the engine is hot or cold, an increase in fuel usage and lack of power when accelerating. Stalling problems can be traced to:
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. Diluted gas may cause your engine to stall.
Dirty Air Filter
As the air filter cleans the air entering the carburetor, it will eventually become dirty or clogged and may prevent the proper amount of air from mixing with the fuel, causing your engine to stall.
Many gas caps also function as a fuel tank vent allowing air into the tank as the fuel is used. The vent may become clogged and preventing air from entering the tank, resulting in poor fuel flow into the engine.
There may be air getting into the engine through a leak in the intake manifold or head gasket. This air will change the air/fuel mixture in the engine and may cause your engine to stall.
Worn or Dirty Spark Plugs
Carbon, oil residue and pitting on the spark plug electrodes will cause a weak or inconsistent spark, resulting in poor ignition and possible stalling
Dirty Fuel Filter
As with your air filter, when the fuel filter does its job, it will become less efficient and may become clogged, restricting fuel flow to the engine.
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 old gas with fresh gas (properly dispose of old gas).
Change air filter if it’s clogged or dirty.
Unclog or replace gas cap if air vent is blocked.
Replace fouled or dirty spark plugs.
Change fuel filter if it’s dirty or clogged.
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 stalling, then it’s time to call on a professional mechanic who specializes in powersport engines.
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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