Can Am Ds 90 No Spark – Your Complete Step-By-Step Diagnostic Guide

There’s nothing more frustrating than getting your kid’s Can-Am DS 90 ready for a day on the trails, only to have it crank and crank but refuse to start. You pull the plug, ground it against the engine, give it a kick, and… nothing. That empty feeling of seeing no blue spark is a real bummer.

But don’t start loading it back on the truck just yet. You’ve come to the right place. Here at FatBoysOffroad, we believe in empowering you to handle these jobs yourself. We’re going to walk you through a logical, step-by-step process to diagnose and fix your can am ds 90 no spark issue, just like a seasoned tech would in the shop.

In this comprehensive guide, we’ll cover the essential tools you’ll need, critical safety checks, and a systematic approach to testing everything from the spark plug to the stator. Our goal is to give you the confidence and knowledge to pinpoint the problem and get that mini-quad ripping again.

Safety First: Pre-Flight Checks Before You Dive In

Before you grab a single wrench, let’s talk safety. Working on any machine, especially with fuel and electrical systems, requires respect and caution. A few minutes of prep can save you a world of hurt.

Stable Ground: Make sure the ATV is on a level, stable surface. You don’t want it rolling away or tipping over while you’re working.
Disconnect the Power: Always disconnect the negative (-) terminal on the battery first. This prevents any accidental shorts that could damage electrical components or give you a nasty shock.
Ventilation is Key: If you end up needing to run the engine (once you have spark!), make sure you’re in a well-ventilated area, preferably outdoors. Exhaust fumes are no joke.
Fire Safety: Keep a fire extinguisher (rated for electrical and chemical fires) within arm’s reach. It’s a cheap insurance policy for your peace of mind and your garage.

Gearing Up: Essential Tools for Your No-Spark Mission

You don’t need a full professional shop to tackle this job, but having the right tools makes the process infinitely easier and more accurate. Guesswork is the enemy of electrical diagnostics.

Here’s your essential toolkit:

Inline Spark Tester: This is non-negotiable. It’s the safest and most reliable way to confirm a no-spark condition. It plugs in between your spark plug and the plug wire and has a small window where you can clearly see the spark (or lack thereof).
Digital Multimeter: This is your best friend for any electrical work. You’ll use it to test for continuity, resistance (ohms), and voltage. Don’t be intimidated; we’ll show you exactly how to use it.
Spark Plug Socket & Ratchet: You’ll need the correct size socket to remove and install the spark plug.
Basic Hand Tools: A good set of sockets, wrenches, and screwdrivers will be needed to remove plastics and access components.

The Spark Trail: A Systematic Can Am DS 90 No Spark Guide

The key to solving a can am ds 90 no spark issue is to follow the path of electricity logically. We start at the end point—the spark plug—and work our way backward. Don’t just start replacing parts; test, don’t guess. This is the core of our can am ds 90 no spark guide.

Step 1: Start with the Obvious – The Spark Plug & Cap

Over 50% of “no spark” issues are caused by something simple right here. Don’t skip this step!

First, unscrew the spark plug cap and use your spark plug socket to remove the plug. Look at its tip. Is it black and sooty (running rich)? Wet with fuel (flooded)? Or is the white ceramic insulator cracked? Any of these can stop a spark. When in doubt, start with a fresh, correctly gapped NGK plug.

Next, use your inline spark tester. Attach it to the spark plug cap and ground the other end to a clean, unpainted part of the engine block. Crank the engine. Do you see a consistent, bright blue light flashing in the tester’s window? If yes, your problem isn’t spark—it’s fuel or compression. If no, continue down the list.

Step 2: Check the Kill Switches and Safety Tethers

Youth ATVs are loaded with safety switches, and they are the most common electrical culprits. These switches are designed to break the ignition circuit, killing the spark.

Handlebar Kill Switch: It sounds silly, but make sure the red rocker switch on the handlebars is in the “RUN” or “ON” position. It gets bumped easily.
Keyed Ignition: Is the key on? Wiggle it a bit. A worn-out ignition switch can have dead spots.
Tether Kill Switch: This is the number one cause of a surprise no-spark condition. The small cap on a cord, usually located on the rear grab bar, must be fully seated. If that cap is missing, loose, or the switch itself is faulty, you will never get a spark. Unplug it and use your multimeter on the continuity setting to test the switch itself.

Step 3: Inspect the Ignition Coil

The ignition coil is a small transformer that converts the low voltage from your electrical system into the thousands of volts needed to jump the spark plug gap. It’s usually a small black box or cylinder mounted to the frame with the thick spark plug wire coming out of it.

Set your multimeter to measure resistance (Ω). You’ll perform two tests:

Primary Winding: Disconnect the small wires going to the coil. Touch one multimeter probe to each of the small terminals. You should see a very low reading, typically between 0.2 and 1.5 ohms.
Secondary Winding: Touch one probe to one of the small terminals and the other probe inside the spark plug cap (make sure it’s touching the metal contact). You should see a much higher reading, usually between 5,000 and 15,000 ohms (5kΩ – 15kΩ).

If either reading is “OL” (open loop/infinite resistance) or way outside the expected range, your coil is likely bad.

Step 4: Test the CDI Box (Capacitor Discharge Ignition)

The CDI is the “brain” of the ignition system. It takes signals from the stator and pickup coil and decides exactly when to tell the ignition coil to fire. It’s a little black box with a wiring harness plugged into it.

Unfortunately, you can’t reliably test the CDI box itself without special equipment. However, you can test the signals going into it and coming out of it. This is one of the most valuable can am ds 90 no spark tips we can offer. You’re confirming everything else is working, and if it is, the CDI is the likely culprit by process of elimination.

You’ll need a wiring diagram for this, but generally, you’ll check for AC voltage coming from the stator while cranking, a small AC pulse from the pickup coil while cranking, and you’ll check for continuity on the kill switch wire to ground.

Step 5: Digging Deeper – The Stator and Pickup Coil

This is the most involved step. The stator and pickup coil live inside the left-side engine cover, sometimes in engine oil. The stator generates the power for the ignition system, and the pickup coil (or pulser coil) sends a timing signal to the CDI.

Find the wiring harness coming from the engine case. Unplug it. Using your multimeter set to resistance (Ω), you can test the components right from the plug. You’ll need your service manual or a reliable online source for the correct wire colors and resistance specifications.

Typically, you’ll measure the resistance of the source coil (powers the CDI) and the pickup coil. If you get a reading of “OL” or a value far from the spec, you’ve found your problem. Replacing a stator is a more advanced job, but entirely doable for a careful DIYer.

Step 6: Don’t Forget the Wiring Harness!

Before you order any parts, do a thorough visual inspection of the entire wiring harness. Look for wires that have been rubbed raw against the frame, chewed by mice (a common problem!), or have green, corroded connectors. Pay special attention to the main frame ground wire. A loose or corroded ground can cause all sorts of electrical gremlins, including a no-spark condition.

Common Problems with Can Am DS 90 No Spark & Quick Fixes

Feeling overwhelmed? Let’s boil it down. Before you tear the whole engine apart, check these common culprits that account for the vast majority of issues:

Faulty Tether Kill Switch: The cap is loose, missing, or the switch is internally broken.
Fouled or Bad Spark Plug: It’s a cheap and easy replacement. Just do it.
Handlebar Kill Switch is Off: Don’t laugh, it happens to everyone.
Spark Plug Cap Isn’t Seated: The cap should click firmly onto the top of the spark plug. Sometimes they vibrate loose.
Corroded Connector or Bad Ground: Look for the easy-to-reach plugs and the main ground wire from the battery to the frame. Clean them up.

Best Practices for a Healthy Ignition System

Once you solve your problem, you want to keep it from happening again. Adhering to some can am ds 90 no spark best practices will save you headaches down the road. Think of this as your long-term can am ds 90 no spark care guide.

A key part of a sustainable can am ds 90 no spark approach is to diagnose before you replace. Throwing parts at a problem is expensive and wasteful. By testing each component, you only replace what’s actually broken. This is an eco-friendly can am ds 90 no spark strategy that also saves you money.

Regular Plug Changes: Change the spark plug at least once a season, or more if you ride frequently.
Use Dielectric Grease: Put a small dab of dielectric grease in the spark plug boot and on all major electrical connectors. This keeps moisture and corrosion out.
Secure the Harness: Use zip ties to ensure the wiring harness isn’t rubbing against the frame or engine, preventing future shorts.
Proper Storage: If storing the ATV for a long period, keep it in a dry place and connect the battery to a tender to keep it healthy.

Frequently Asked Questions About Can Am DS 90 No Spark

What’s the correct spark plug gap for a Can-Am DS 90?

The standard spark plug gap for most DS 90 models is between 0.024″ and 0.028″ (0.6mm – 0.7mm). However, always check your owner’s manual for the exact specification for your model year.

Can a weak battery cause a no-spark issue?

Yes, absolutely. While the ignition system on many DS 90s gets its primary power from the stator, the whole system relies on a good ground and a stable electrical environment. A very weak or dead battery might not provide enough cranking speed to generate a sufficient charge from the stator, leading to a weak or non-existent spark.

My DS 90 has spark, but still won’t start. What now?

Spark is just one of the three ingredients an engine needs. You also need fuel and compression. If you’ve confirmed you have a good, strong spark, the next step is to check if you’re getting fuel (is the carb clean? is the petcock on?) and then to check for engine compression with a compression tester.

Get Back on the Trail

Troubleshooting a can am ds 90 no spark issue can seem daunting, but it’s all about being patient and methodical. By following the spark from the plug back to its source, you can isolate the faulty component without guesswork.

Remember to always start with the simplest things first: the plug, the cap, and those tricky kill switches. More often than not, your solution is hiding in plain sight. Take your time, trust your multimeter, and you’ll have that little engine purring in no time.

Now get out there, get it fixed, and hit the trails! Ride safe.

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Thomas Corle

Founder & Automobile expert at FatBoysOffroad

Automobile expert and off-road enthusiast, sharing in-depth knowledge of vehicles, gear, and adventures. Helping readers make smart decisions and enjoy the thrill of off-roading safely and confidently.