Polaris Sportsman Bad CDI Symptoms!

Thousands of miles of bumping down the highway may take their toll on a vehicle’s suspension. A black box may be damaged or destroyed by heat as well. Finally, if you find it difficult to use, it should be verified thoroughly.

And you’re here to know what are the Polaris sportsman’s bad CDI symptoms.

Bad CDI might refuse to start because of a loose connection. This might fail to begin. This will happen if gasoline is low. Backfiring and misfiring are the two major troubles you might face. Polaris sportsman might be overheated. Insufficient fuel might cause this to stall or lose power.

Don’t get too stunned after noticing any Polaris sportsman bad CDI issues. It can be fixable. Just pay attention to the following details.

Let’s dive into the oceans of details-

Possible Polaris Sportsman CDI Symptoms & Problems

So, the first thing you’re wondering what are the symptoms of bad CDI box? Well, there are multiple reasons that you might face. You may also think, how do you diagnose a bad CDI? Nothing to worry about.

Polaris Sportsman CDI

You can fix those troubles with easy hacks and proper guidance. But, for now, let’s figure out what major trouble you can possibly face.

Loose Connection

Polaris offers three possible causes and treatments for a non-starting engine. First, owners should check for low battery voltage by charging the battery to 12.8 VDC.

The solenoid or the battery may have loose connections, causing the issue. However, owners should make sure that everything is secure before proceeding.

Failing to Begin

You may need to check ATV’s fuel supply as a last resort. Fill the tank if that is the case. Then press the cycle key three times for five seconds each time. The engine should start if gasoline is low.

Alternatively, the gasoline may include water or be too old, necessitating a complete drain and refill. Spark plugs should be checked and changed if required. If they are faulty or are not receiving any spark, you might face troubleshooting.

Polaris suggests that customers see a Polaris dealer for three additional possible issues.


Some of the causes of an engine backfiring include a weak spark or corroded. It can also be soggy gasoline, faulty ignition connections, or an improper spark plug gap.

Spark plugs should be checked, cleaned, and replaced as necessary. The proper gap distance should be established.

All linkages should be examined and adjusted once the fuel has been drained and replenished. Consult a Polaris dealer if you suspect any additional issues. Such as improperly placed spark plug wires, wrong ignition timing, or exhaust leaks.


Can bad CDI cause weak spark? It is conceivable that the spark plugs need to be checked. It should be cleaned or changed if the engine stalls, misfires, or operates erratically. If the battery voltage is low, this might be the problem.

There may also be faulty or water-filled gasoline that must be emptied and changed. Moreover, A rider’s engine may stall if he or she starts and stops the bike too quickly.

In this instance, a rider should wait until the engine has warmed up completely before starting it up.

The reverse speed restriction does not function if the fuel filter is clogged. Maybe the spark plug wires are worn or damaged. And the electronic throttle control is not working. If there is any other mechanical issue, contact your local dealer.


A clog in the screen might cause the Polaris Sportsman’s overheat. The debris must be cleared away before any additional work can be done. The radiator might be clogged. If the radiator fins are dirty, the owner may clean them with a garden hose.

Using forceful hoses might damage and distort these fins. Hence Polaris advises against this.

Putting an End to or Losing Power

Insufficient fuel might cause the Polaris Sportsman to stall or lose power. A vehicle’s cycle key needs to be turned to its “on” position three times before it may be restarted.

It may be necessary to investigate the last option. Replace a gasoline vent line that has been damaged or obstructed.

Also, if the gasoline is watered down or wrong, the engine will shut down. Spark plugs should be cleaned and changed if required. Ignition connections should be checked and adjusted. A trip to a Polaris dealer is necessary if your engine continues to lose power.

Possible causes include broken spark plug wires, a reverse speed limiter or electronic throttle control problem, or another mechanical failure.

Easy Solutions to Polaris Sportsman Bad CDI Troubleshooting

Now that you know the possible symptoms and problems, You can solve them easily. Don’t worry I have the solutions too! Have a look.

Polaris Sportsman Bad CDI Troubleshooting Fix

Clear the Bank

Make sure the bank is entirely clear of combustible substances like gasoline. Starting the ATV may generate air and fuel to operate the engine. You must first check to see whether the battery is completely drained before proceeding.

CDI Module should be Removed

Find the black box usually beneath the pilot’s seat. Identify it by the two plugs and a bullet connection it possesses. Remove it as quickly as possible to get to the interconnects below it.

You may and should consult the service handbook at this point. To uninstall the CDI module, you must rigorously follow the instructions indicated in the text. You may do this without inflicting any significant damage due to a lack of preparation.

The black box’s resistance should be measured with an ohmmeter with the ATV switched off. Cool before doing this step.

The Resistance Test is a Must

The electrical resistance of an ATV might vary depending on the model. This technical characteristic can be seen on the coil.

Therefore, you should look for it to determine what register is typical. If the resistance values are observed, you can tell if a coil has been damaged. Do not match those stated on the coil.

You may also examine the technical characteristics part of your owner’s handbook. See the vehicle’s allowed resistance level.

Measuring the Resistance of the Primary Coil

This is the principal winding resistance of the CDI module distributor.

Secondary Coil Resistance Testing

A connection between the ignition coil’s main wire. Its distributor must be made by touching both its exterior and internal contacts.

A CDI module must be changed. The main and secondary winding registers may not meet the prescribed technical criteria. A process referred to as secondary winding resistance.

You might wanna know, can you bypass a CDI box? The answer is No. Unless you’re a professional, it is better to avoid it.


If you are finally done checking, and it’s impossible to fix, purchase these suggested ones to replace.


What happens if CDI is not working?

A defective CDI box’s obvious symptoms might go in many different ways. This makes it difficult to identify. Sparks may not even appear when a faulty CDI is to blame. Misfires, hard starting, sluggish performance, and even stalling are all signs that your CDI box will fail.

How do I know if my CDI box is bad?

When anything goes wrong with your engine’s running, you may notice misfiring. You’ll also see dead cylinders, backfire, strange behavior on the tachometer, and other issues. Warming up the bike may exacerbate the situation. In other cases, the engine may not even be able to maintain low RPMs.

How do you test a CDI?

You’ll first need to hook up the multimeter’s leads. For digital multimeters, the beeping sound is audible. Make sure the ground and other sites are connected by measuring for continuity. You shouldn’t hear any noises if your CDI is operating properly.

Bottom Line

I hope you are now clear about your Polaris Sportsman bad CDI Symptoms. Contact a professional if you think the issues are too much to care for yourself.

Its lifespan is determined by how it is used and maintained. This portion and its delicate parts will be sensitive to driving and climatic circumstances.

The longevity of whatever we value depends on how well we care for it.

Best of luck!

Mark Williams

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