There’s nothing that grinds a weekend to a halt faster than a kid’s ATV that won’t start. You hear the engine turn over, but it just won’t fire up. That sinking feeling means you’re likely facing the classic polaris predator 90 no spark issue, a common but frustrating problem for many owners.
Don’t throw in the towel and load it up for a costly trip to the shop just yet. We promise to guide you through a logical, step-by-step diagnostic process that any determined DIYer can follow. You can pinpoint the exact cause of your ignition failure with just a few common garage tools.
In this ultimate guide, we’ll start with the laughably simple fixes that solve the problem 80% of the time. Then, we’ll dive deeper into testing each component of the ignition system, from the spark plug to the stator, giving you the confidence to tackle this job yourself and get that little ripper back on the trail.
First Things First: Safety and Basic Checks Before You Dive In
Before we start slinging wrenches, let’s cover the basics. Rushing into a diagnostic can lead you down a rabbit hole. A methodical approach always wins. This is one of the most important polaris predator 90 no spark tips we can offer.
First, ensure the ATV is on level ground in a well-ventilated area. Safety glasses are non-negotiable when working with tools and electrical systems.
Essential Tools for the Job
You don’t need a full professional shop, but having these tools on hand will make the job much smoother. You likely have most of them already.
- A good quality multimeter (for testing resistance and voltage)
- A spark plug socket and ratchet
- An in-line spark tester (highly recommended for safety and accuracy)
- Basic screwdriver and socket set
- Wire brush and contact cleaner
- Dielectric grease
The “Are You Sure?” Checklist (The Simple Stuff)
It sounds silly, but you’d be amazed how often the problem is one of these simple switches. Check them all twice before you proceed.
- The Key: Is the ignition key turned to the “ON” position? Yes, we have to ask.
- The Kill Switch: Is the handlebar kill switch in the “RUN” position? It’s easy to bump this switch by accident.
- The Tether Cord: This is the number one culprit for a surprise no-spark condition. The rear tether kill switch must have its cap fully seated. If the cap is missing or loose, you will get no spark. Wiggle it and make sure it’s on tight.
The Heart of the Spark: Inspecting the Spark Plug and Cap
If the basic switches check out, our next stop is the end of the line: the spark plug itself. This component lives a hard life and is a common failure point.
How to Properly Test Your Spark Plug
The best way to test for spark is with an in-line spark tester. It’s a cheap tool that connects between the spark plug and the plug wire, and it will light up brightly if a spark is present. It’s much safer than the old-school method.
If you don’t have one, you can use the traditional method, but be careful. Here’s how to polaris predator 90 no spark test the old way:
- Remove the spark plug wire and use your spark plug socket to remove the spark plug.
- Reconnect the spark plug to the plug cap.
- Using insulated pliers, hold the metal threads of the spark plug firmly against a metal part of the engine block or cylinder head. This creates a ground.
- Have a helper crank the engine while you watch the tip of the spark plug. You are looking for a strong, bright blue spark. A weak, orange spark is just as bad as no spark.
If you have no spark or a weak spark, try a brand-new, correctly gapped spark plug before moving on. They are cheap and a regular maintenance item anyway.
Checking the Spark Plug Cap and Wire for Damage
While the plug is out, inspect the spark plug cap (the “boot”). Look for cracks or corrosion inside. The cap should screw onto the wire. You can try unscrewing it, trimming about 1/4 inch off the end of the wire to get to fresh conductor, and screwing the cap back on tightly.
Your Complete Polaris Predator 90 No Spark Guide
Okay, the simple stuff didn’t work. Now it’s time to trace the problem backward through the ignition system. This is where your multimeter becomes your best friend. We’re moving from the plug to the coil, then the CDI, and finally the stator.
Step 1: Testing the Ignition Coil
The ignition coil’s job is to take the low voltage from the CDI and transform it into the high voltage needed to jump the spark plug gap. It’s a common failure point.
Most coils have a primary and secondary winding that can be tested for resistance. You’ll need to disconnect the coil’s wires to get an accurate reading. Check your service manual for the exact specs, but you’re generally looking for a low resistance (e.g., 0.1-0.5 ohms) on the primary side and a much higher resistance (e.g., 6,000-15,000 ohms) on the secondary side.
If you get an “OL” (open loop) reading on your multimeter, the coil is bad and needs to be replaced.
Step 2: Checking the CDI Box (The Brains of the Operation)
The CDI (Capacitor Discharge Ignition) box is the brain of your ignition system. It tells the coil when to fire. Unfortunately, it’s very difficult to test a CDI box directly without specialized equipment.
The most common diagnostic method is to test all other components first. If the spark plug, coil, and stator all test good, the CDI is the most likely remaining culprit. Before replacing it, carefully inspect the wiring harness plug at the CDI for any loose, corroded, or pushed-out pins.
Step 3: Inspecting the Stator and Pickup Coil
The stator, located behind the flywheel on the side of the engine, is what generates the electrical power for the ignition system. It has multiple windings, and if one of them fails, you’ll lose spark.
You can test the stator’s resistance values at its main connector plug without removing the engine cover. You’ll need a service manual for your specific year to know which color wires to probe and what the correct ohm readings should be. A reading that is way off or shows an open loop indicates a failed stator.
Common Problems with Polaris Predator 90 No Spark and Their Solutions
Over the years, we’ve seen a few recurring themes with these little ATVs. Understanding these common problems with polaris predator 90 no spark can save you hours of frustration.
The Notorious Tether Kill Switch
We mentioned it once, but it’s worth repeating. The rear tether pull-cord switch is responsible for a huge percentage of these issues. They get corroded, the cap gets lost, or the internal switch fails. For testing purposes only, you can often unplug this switch from the wiring harness to bypass it and see if your spark returns.
Corroded Connectors and Grounds
These machines live in the dirt and mud. Every single electrical connector is a potential failure point. Unplug every connection you can find in the ignition circuit, inspect for green or white corrosion, and clean them with a contact cleaner and a small brush. A bad ground wire from the engine to the frame can also cause all sorts of electrical gremlins.
Water Damage After a Wash or Creek Crossing
Did the no-spark issue appear right after a power wash or a deep puddle? Water has likely found its way into a connector, the spark plug boot, or the kill switch. Use compressed air to blow out all the connections and let the machine dry thoroughly.
Best Practices for a Healthy Ignition System: Your Care Guide
An ounce of prevention is worth a pound of cure. This polaris predator 90 no spark care guide will help you avoid future issues and keep the machine reliable for years to come.
Regular Cleaning and Inspection
Make it a habit to inspect the main wiring connections every few rides. Look for chafed wires or connectors that are starting to work loose. Keeping the machine clean helps you spot these issues early.
Using Dielectric Grease
This is one of the best polaris predator 90 no spark best practices. After cleaning any electrical connector, apply a small amount of dielectric grease before plugging it back in. This non-conductive grease seals out moisture and prevents corrosion, the number one killer of electrical connections.
Why Fixing is the Sustainable Choice
In a world of disposable products, taking the time to diagnose and repair your ATV is a truly sustainable polaris predator 90 no spark solution. You’re saving a machine from the landfill, learning a valuable skill, and avoiding the environmental impact of manufacturing and shipping a new vehicle. That’s a win-win-win.
Frequently Asked Questions About Polaris Predator 90 No Spark
Can a bad battery cause a no-spark issue on a Predator 90?
Yes, indirectly. While the stator generates the power for the spark itself, the battery is needed to turn the starter motor. If the battery is too weak to spin the engine over fast enough, the stator may not generate enough voltage to create a spark. Always start with a fully charged battery.
How do I know if my CDI box is bad?
It’s a process of elimination. There isn’t a simple resistance test for a CDI box like there is for a coil or stator. You confirm that the stator is sending a signal to the CDI, the kill switch circuits are okay, and the coil is good. If all those parts check out and you still have no spark, the CDI is the most likely failed component.
What are the resistance specs for the Predator 90 stator?
These specs can vary slightly by year. It is highly recommended to get a factory service manual for your specific model. Generally, you’ll be looking for a certain resistance between the trigger coil wires and another resistance value for the source coil wires. A manual will give you the exact wire colors and ohm ranges to look for.
With this guide, you have a clear roadmap to diagnosing that frustrating polaris predator 90 no spark problem. Remember to work methodically, start with the simplest solutions first, and never overlook the basics like the tether switch. Taking your time and being thorough is the key to success.
You’ve got this. That feeling of accomplishment when you hear that engine fire back to life is what being a DIYer is all about. Now get out there, solve the problem, and get that little rider back on the dirt where they belong!
- Can-Am Outlander Years To Avoid – A Mechanic’S Guide To Buying Smart - November 30, 2025
- Polaris Sportsman 570 Vs Can Am Outlander 700 – The Ultimate Off-Road - November 30, 2025
- Can Am Outlander Fuel Pump Problems – Your Complete DIY Diagnostic & - November 30, 2025