ATVs are designed to provide you with a seamlessly exhilarating ride across rough terrain. However, they can also be a source of unnerving experiences, such as when they idle too high. When this happens, the vehicle’s engine begins to sound louder than usual and the ATV might start shaking. Thankfully, high idling is not the end of the world because, as is the case with most ATV issues, it can be fixed fairly easily.
What are the signs of an idling ATV?
The most obvious sign that you have an idle issue with your ATV is when it is louder than usual. A loud ATV, especially when you are revving the engine, likely means that your vehicle is idling high or idling rough.
Another sign that your ATV may be idling high is if it is drinking more fuel than usual. This happens because when your car is idling, the engine remains on and uses up its stores of fuel.
Finally, high idle problems might be a problem if your vehicle gets jolted into gear. A good automatic ATV should shift into gear smoothly, without any trouble. However, if you have an idling problem, you will find this transition to be far less smooth than usual. Instead, you will experience your ATV jolting or jerking into gear, which can lead to an unpleasant drive.
What does a high idle indicate?
A high idle suggests that your ATV continues to run even when it is in an idle position. It means that your ATV is revving too quickly, when in a parked or neutral position. When it is idling high, it indicates that the idle speed is high as it is registering more revolutions per minute.
For smaller engines, you should expect the RPM to be around 750 when the engine is warm. If it is significantly higher than 500 (coming in at 900 or more), it suggests that the engine is still running and failing to idle properly.
What causes high idle speed?
There are a few different things that can affect your ATV's idle speed. Once you are able to identify the source of the problem, it is easy to fix in most cases. In order to help you identify what exactly is causing the high idle speed in your vehicle, we have collated this list of the most common causes of idling problems in ATVs.
A vacuum leak is one of the most common carburetor problems. It occurs when the seal between the carburetor and the engine is not properly working, as a result of which the vacuum that should be maintained is compromised. When the seal starts to malfunction, air begins to enter the engine, which creates what is known as a lean mixture.
Not only will this cause your ATV to idle high, but it will also cause your vehicle to start jerking more than normal, which can be dangerous as it means that you won’t be able to control it properly. It is fairly easy to identify a vacuum problem, as you can visually inspect whether or not the seal is intact. If you cannot see an obvious problem, you can buy a vacuum tester, which will confirm or deny whether you have a problem with your vacuum seal.
Clogged pilot jet
A clogged pilot jet, like a vacuum leak, is also caused by fuel coming in contact with air. However, unlike the latter, where you have too much air mixing with your fuel, if your pilot screw is clogged, you will get too little air coming into your fuel. This will create a lean mixture and your ATV will idle high.
It is often difficult to clean your pilot jet because the component is too small. This is why it is beneficial to seek the assistance of a mechanic who can remove the small jet and use tools to clean it and get your engine speed back to normal.
Idle screw in wrong position
Your idle speed screw is the component whose job it is to control how much air enters the fuel. If you have accidentally re-positioned the screw, it will mean that the wrong amount of air will enter the fuel mixture, which will cause the engine to idle.
This is a simple problem to fix. All you need to do is find your vehicle's instruction manual, which will let you know how the idle set screw should be positioned. You then need to simply return the screw to its original position, and you will have the correct mixture of air and fuel to return to regular engine idle speed.
Dirty air filter
The aim of an air filter is to ensure that only clear air makes it to your engine. In order to achieve this, the air filter collects any debris or contaminants that make their way into the vehicle through the air, and filters them out.
A dirty air filter will be inefficient, thereby allowing more and more debris and dirt to enter the fuel. When this happens, the ATV will idle high. If your air filter is dirty, all you need to do is swap it for a new one. We recommend regularly installing a new air filter in order to avoid this becoming a problem.
Throttle cable issues
Issues with the throttle cable, sometimes called choke cable, can also cause your ATV engine to idle. If your cable is stuck, there is a good chance that it could be causing extra air to enter the fuel. This can be resolved by unsticking the cable.
Although this might require some work, it is a relatively easy process. All you need to do is apply some lubricant to the throttle cable and continuously move it up and down using pliers. Doing this will get movement back into the cable until it can freely move on its own again.
Changes in the temperature can be a cause of high idling. When the weather is warm outside, the fuel vaporizes with ease, which allows the ATV to run smoothly. However, when the weather gets colder, the fuel thickens, thereby making it harder for the engine to adequately pump it to where it needs to be. This might cause high idling, or similar issues.
Before checking for all of the other possible causes of high idling, consider the possibility that the sole cause of your vehicle playing up might be the weather. If that is the case, you will not need to do anything to your ATV, but wait for more favorable conditions.
How do I adjust the idle on my ATV?
How you adjust the idle on your ATV will depend on the specific model that you have, as each has slightly different requirements. This is why it is important to consult your user manual before making any changes. However, the universal idle adjustment tool is the airscrew.
The idle screw, or idle air control valve controls how much air is let into the fuel, but sometimes it can be misaligned. Therefore, if you are sure that there are no structural issues with your ATV, but it is idling high, you should adjust the airscrew. Simply read your manual to find out where exactly your screw should be sat and adjust it to that position. Once you have done this, your engine idle should disappear and you will be back to riding as usual.
Shop for ATV accessories
Owning an ATV is all about customization. Once you have the vehicle running safely, with no idling problems, you want to make it your own. The best way to do this is by adding accessories to your vehicle that will set it apart from other ATVs and endow it with its own unique personality.
At Perfex Industries, we offer a wide range of ATV accessories. Whether you want to protect the bottom of your vehicle with a skid plate for safer driving or add suspension kits to your wheels to give your ride a bounce, we are the one-stop shop for all of your ATV needs.