Polaris Sportsman 90 No Spark [6 Reasons & Its Solutions!]

Are you having trouble with your Polaris Sportsman 90? Many riders have had the same problems with their beloved off-road vehicle, where sparkings suddenly stop.

We will explore the six most common reasons behind the Polaris Sportsman 90 no spark issue.

The main reasons behind no spark are faulty and dirty plugs, damaged wires, wide or narrow gaps, and bad ignition coils and stators. The solutions vary from cleaning and repairing to straight replacement. It is good to perform regular maintenance to avoid such issues.

The necessary fixes and suggestions will get you back in the driver’s seat in no time, so keep reading on!

How Do You Diagnose No Spark On An ATV?

ATV No Spark Problem Fixing

If there is no spark on an ATV rider, the engine will not start. The engine needs the spark to ignite the fuel and create the power needed for the ATV to run.

The spark is usually caused by a spark plug, which may need to be replaced if it has malfunctioned or worn out. As a result, the ATV will not be able to power on, and the rider will not be able to ride the ATV.

However, there is more to it, and we will explore further to solve specific issues. 

6 Reasons Behind Polaris Sportsman 90’s No Sparks Issues

There are many reasons why Polaris Sportsman 90 may experience no sparks. Here are six of the most common ones indicated with symptoms and solutions.

Faulty Spark PlugEngine Sounding RoughReplace The Spark Plug
Dirty Spark PlugSlow AccelerationClean And Lubricate The Spark Plug
Damaged Spark Plug WiresProblems Starting The EngineReplace The Wires
Gaps In Spark PlugsPoor Gas Mileage Or Loss Of PowerAdjust The Gaps
Bad Ignition CoilVehicle BackfiringReplace The Ignition Coil
Bad Stator Poor Engine Performance Or The Machine Won’t StartStator Test For Necessary Repair Or Replacement

Since this is a summary of all the insights that can be found, let’s head forward in detail! Each reason will follow the symptom where the necessary fixes are provided. 

Reason 1: Faulty Spark Plug

The most common reason for a faulty plug is that it has become fouled, which can happen when it gets coated in oil or carbon deposits.

If the electrode on the spark plug becomes too covered in deposits, it can prevent an adequate spark from being created. Therefore, do not use the vehicle until the necessary fixes are made. 

Symptom: Engine Sounding Rough

The faulty plug will result in poor engine performance, and the engine will make rough sounds while riding. Out of all the models, 2002 and 2005 Polaris Sportsman, 90 ATV owners have been known to report this issue.

Solution: Replace The Spark Plug

You can do the replacement process in a few steps:

  • When replacing a spark plug, first ensure that the engine is turned off and cool. 
  • When ready, locate the spark plug wire and remove it from the spark plug. Be careful not to damage the wire while doing it.
  • Then, use a socket wrench from the tool set to remove the spark plug from the engine(our pick: DEWALT Mechanics Tools Kit and Socket Set). 
  • Be sure to hold onto the old spark plug so you don’t lose any pieces.

At the end of it, insert the new spark plug into the engine and tighten it with the wrench. Reattach the wire to the plug and start up your ATV!

Reason 2: Dirty Spark Plug

If the air filter is not properly cleaned or replaced, it can cause dirt and dust to enter the engine and clog the spark plugs. In case the engine is not properly lubricated, it can also cause the spark plugs to become dirty.

This is a common issue among all the Polaris Sportsman 90 models from 2002 to 2008. Such issues usually cause increased emissions and fuel consumption.

Symptom: Slow Acceleration

A dirty spark plug will cause a decrease in acceleration because it can lead to a lack of spark. The dirt prevents the fuel and air from combusting properly, decreasing power and acceleration. 

Solution: Clean And Lubricate The Spark Plug

Here are some points to consider while applying the fix:

  • The spark plug should be cleaned with a wire brush to remove any corrosion or dirt. 
  • You can perform a deeper cleaning with soap and water by rinsing the surface with a wet cloth. 
  • The plug should then be lubricated with light oil(our pick: 3-IN-ONE 100355 Multi-Purpose Oil). To do so, you have to remove the spark plug. After that, you can apply a light coat of oil to the threads of the spark plug.

This shall bring the spark plug back to life, and the spark will happen. 

Reason 3: Damaged Spark Plug Wires

At any point in the operational journey of the ATV, the wires can become loose and start to rub against the exhaust pipe. This damages the wires while also causing insulation, leading to a short circuit.

Other causes of damage can include constant exposure to moisture and extreme heat.

Symptom: Problems Starting The Engine

Damaged spark plug wires cause problems with starting the engine because they can interrupt the flow of electricity to the spark plugs. This can cause the engine to misfire, making it difficult to start.

Solution: Replace The Wires

The simple solution is to replace the wires; you don’t want to keep the old wires anymore. Here are the two steps you can take to install new spark plug wires by replacing the old ones: 

  • Remove the old ones by unplugging them using wire removal tools
  • Plug in the new spark plug wires after removing the old one, matching the correct wire to the correct plug.

The simple tool you need to use is a wrench, and you will be good to go. 

Reason 4: Gaps In Spark Plugs

There can be too wide or too narrow gaps in the spark plugs because the electrodes on the spark plug are dirty or corroded. Also, after a long time of use, the plugs may move out of position when corrosion density infiltrates. 

The size of the gap between the electrodes in a spark plug directly affects the performance of the ATV. 

Symptom: Poor Gas Mileage Or Loss Of Power

A larger gap will cause less current to flow through the plug, resulting in decreased power and gas mileage.

Solution: Adjust The Gaps

The electrodes will need to be cleaned or replaced to fix the problem. You can clean the way described before with a wet cloth mixed with soap and water. However, for the replacement, take assistance from qualified mechanics.

Here are a few points:

  • You can adjust the gaps by using a feeler gauge to set things evenly. 
  • In contrast, If the gap is too wide, you can use a wire brush or a grinding stone to narrow it. 
  • If the gap is too narrow, you can use a file or sandpaper to widen the gap.

As you are not doing this work every day, take good assistance from those who do it every day and so the quality of finishing will be better. 

Reason 5: Bad Ignition Coil

The ignition coil goes bad due to wear and tear, exposure to moisture, and electrical problems. Usually, the lifespan of an ignition coil is around 100,000 miles, especially in the latest 2006 to 2008 Polaris Sportsman 90 models.

If your Polaris has crossed that mileage, the ignition coil can cause no spark in the system due to the fuel and air mixture inside the engine igniting prematurely. 

Symptom: Vehicle Backfiring

When an ignition coil experiences a failure, it can cause the vehicle to backfire. This is because they misfire when the spark plugs fail to receive the correct amount of electricity. 

Solution: Replace The Ignition Coil

To replace the ignition coil, you must remove the old one and follow a step-by-step process. For the entire process to happen, You will need a socket wrench set, a flat-head screwdriver, a spark plug socket, and a replacement ignition coil.

And so, the process will go like this:

  • For this, you must first disconnect the battery’s negative terminal. This will help avoid any accidental sparks when working on the ignition coil. 
  • Once the battery is disconnected, you can remove the spark plug wires from the ignition coil. Clips or connectors usually hold the wires in place and release them to pull them free.
  • After that, remove the mounting bolts holding the ignition coil. These bolts can usually be undone with a socket wrench. 
  • You can lift the ignition coil out of its housing after removing the bolts.

Installation of the new ignition coil is simply a reversal of these steps. Be sure to reconnect the battery’s negative terminal once the installation is complete.

Reason 6: Bad Stator

ATV Bad Stator

On many occasions, the stator may overheat if it is not adequately cooled. This can happen if the ATV is ridden for extended periods at high speeds or used in off-road conditions where there is a lot of dust and dirt.

A bad stator can also damage other electrical system parts. The stator is responsible for providing power to the ignition system. If it is bad, it can cause a loss of spark due to insufficient power being delivered to the ignition system.

A faulty stator can also cause a loss of spark due to the stator’s output being distorted or misfiring.

Symptom: Poor Engine Performance Or The Machine Won’t Start

A bad stator can cause poor engine performance. The vehicle will not start because it disrupts the spark plugs’ electrical flow, causing a misfire or reduced power. 

Solution: Stator Test For Necessary Repair Or Replacement,

First, remove the stator from the vehicle to conduct a stator test to repair or replace a bad stator. After removal, test the stator for continuity using a digital electrical testing multimeter(our pick: Klein Tools Digital Multimeter Electrical Test Kit). Also, inspect the wiring to see if the system needs repair or replacement.

If the stator is old, an expert opinion would tell you to replace the stator rather than repairing. The process of replacing is similar to what was explained before with the ignition coil. However, it is good that a qualified mechanic does the job. 

How To Avoid No Sparking Issues On ATVs

2003 Polaris Sportsman 90 Maintenance

Avoiding no-sparking issues on ATVs is an essential step in ensuring safety and efficiency. To ensure that your ATV is in good working condition, here are the things you can do:

  • Frequently check to ensure the spark plug wire is firmly connected to the spark plug and the ignition coil.
  • Regularly clean the air filters.
  • Ensure the ignition timing is set correctly.
  • Check if all electrical components and cables are properly grounded.
  • Keep checking if the ignition coil works properly and delivers the correct voltage.

These simple maintenance ideas will help you prevent any electrical malfunctions inside the vehicle.


How do you check a spark on an ATV?

To check a spark on an ATV, remove the spark plug, connect a tester to it, and ground it on the engine block. Next, pull the starter cord and look for the spark between the spark plug and the tester electrodes.

Will a CDI box cause no spark?

A CDI box is responsible for creating a spark in the ignition system, so if it is not functioning correctly, there will be no spark. This can be caused by a faulty CDI box or an electrical issue with the wiring.

How do you check a spark with a multimeter?

To check a spark, connect the positive lead of the multimeter to the spark plug terminal and the negative lead to the spark plug body. Then, set the multimeter to ohms and measure the resistance of the spark plug. See if the resistance level is higher or lower than what is recommended. 


On various models, the Polaris Sportsman 90 no spark can be solved easily when you follow the directions provided. Don’t forget to consult professionals to ensure a durable and long-lasting machine, giving you the best times.

This is it for now. We must go now, goodbye!


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