That constant chain rattle on your kid’s Polaris Outlaw 90 isn’t just annoying. It’s the sound of a problem waiting to happen on the trail—a warning sign of a loose chain that can sap power, cause excessive wear, and even become a serious safety hazard.
You’ve probably agreed that a sloppy, clanking chain just isn’t right. It leads to jerky acceleration and increases the risk of the chain derailing, which can lock up the rear wheels or damage the engine case in an instant.
I promise that in this comprehensive guide from FatBoysOffroad, we’ll walk you through every step of a proper polaris outlaw 90 chain tensioner install. We’ll turn that noisy, inefficient drivetrain into a smooth, reliable, and safer system for your young rider.
You’re about to learn why this is one of the best upgrades for a youth ATV, what tools you’ll need, and exactly how to perform the installation like a pro. We’ll also cover common mistakes to avoid and how to care for your new setup.
Why Bother? The Top Benefits of a Polaris Outlaw 90 Chain Tensioner Install
Before we grab the wrenches, let’s talk about why this project is so important. Installing a chain tensioner isn’t just about quieting down the machine; it’s a fundamental upgrade for safety, performance, and longevity. The benefits of a polaris outlaw 90 chain tensioner install are immediate and significant.
Enhanced Safety and Reliability
This is the number one reason. A loose chain can easily jump off the sprockets, especially during bumpy rides or sudden changes in throttle. This is called “throwing a chain.”
When this happens, it can lock the rear axle, causing an abrupt stop or a loss of control. A quality tensioner keeps consistent pressure on the chain, drastically reducing this risk and giving you peace of mind.
Improved Performance and Throttle Response
All that slop in a loose chain has to be taken up before power is fully transferred to the wheels. This creates a laggy, jerky feel, especially at low speeds.
A properly tensioned chain provides instant engagement. The result is smoother acceleration, more predictable power delivery, and a more enjoyable, confidence-inspiring ride for your young enthusiast.
Reduced Wear on Drivetrain Components
A slapping chain is a destructive chain. It hammers against your sprockets, swingarm, and frame, causing premature wear on everything it touches. The teeth on your sprockets will get hooked and worn down much faster.
By maintaining correct tension, the chain and sprockets mesh perfectly, leading to a much longer lifespan for your entire drivetrain. This saves you money on replacement parts down the road.
Quieter Operation (Goodbye, Chain Slap!)
Let’s be honest, that constant clatter of a loose chain is grating. It makes the ATV sound old and poorly maintained.
A tensioner completely eliminates that chain slap noise. Your Outlaw 90 will sound healthier, run smoother, and be much more pleasant to ride and be around.
Gearing Up: Tools and Parts You’ll Need
A successful job starts with having the right gear on hand. A proper polaris outlaw 90 chain tensioner install doesn’t require a full professional shop, but a few key tools will make the process smooth and safe. Let’s get our kit together.
Essential Tools for the Job
Gather these items before you begin. There’s nothing worse than having to stop mid-project to run to the store.
- Metric Socket Set & Ratchet: You’ll need various sizes for the axle nuts, mounting bolts, and potentially plastic body panels.
- Metric Wrench Set: For holding nuts while you turn bolts.
- Torque Wrench: Crucial for properly tightening the axle nuts and any tensioner mounting hardware to factory specifications. Guesswork is not your friend here.
- ATV Lift or Jack Stands: You need to safely elevate the rear of the ATV so the wheel can spin freely. Never work on a machine supported only by a jack.
- Safety Gear: Always wear safety glasses and a good pair of mechanic’s gloves.
- Shop Rags & Degreaser: This is a great time to clean the chain and surrounding area.
Choosing the Right Chain Tensioner
You have a couple of options here. The most common style for the Outlaw 90 is a spring-loaded roller tensioner that bolts to the underside of the swingarm.
Look for a kit specifically designed for youth ATVs or the Outlaw 90. These kits often come with the necessary mounting hardware. An aftermarket tensioner from a reputable brand is typically more robust than a generic, no-name part. Make sure it has a quality roller and a strong spring for consistent pressure.
The Complete Polaris Outlaw 90 Chain Tensioner Install Guide
Alright, it’s go time. We’ve covered the why and the what; now for the how. Follow this polaris outlaw 90 chain tensioner install guide step-by-step for a clean and effective installation. Take your time and double-check your work.
Step 1: Safety First – Prep Your Workspace
Safety is non-negotiable. Start by parking the ATV on a level, solid surface like a concrete garage floor. Chock the front wheels to prevent any rolling.
Use an ATV lift or jack stands to securely raise the rear end of the Outlaw 90. Ensure it’s stable before you start wrenching. Giving it a firm shake is a good test. Finally, disconnect the negative terminal on the battery as a precaution.
Step 2: Accessing the Chain and Swingarm
Before you can mount the tensioner, you need a clear view and workspace. Inspect the area around the swingarm and chain.
On the Outlaw 90, access is generally good, but you may need to remove a lower chain guard if one is installed. This is usually held on by a couple of small bolts. Set them aside somewhere safe.
Step 3: Positioning and Mounting the Tensioner
This is the most critical step. The goal is to mount the tensioner so its roller applies upward pressure on the bottom run of the chain, roughly in the middle of its path between the front and rear sprockets.
- Hold the tensioner assembly up to the bottom of the swingarm. Find a flat, strong spot for the mounting bracket.
- Ensure the roller lines up perfectly with the chain. It shouldn’t push the chain sideways at all.
- Check for clearance. Move the swingarm through its full range of travel (you can do this by pushing down on the rear rack) to ensure the tensioner won’t hit the frame, exhaust, or anything else.
- Mark the spot. Once you’ve found the perfect location, use a center punch or a sharp marker to mark where you need to drill the mounting hole(s). Most aftermarket kits will require drilling.
- Drill the holes. Start with a small pilot bit and work your way up to the correct size for your mounting bolts. Use a sharp drill bit and cutting fluid for a clean hole.
- Bolt it on. Securely mount the tensioner bracket to the swingarm using the provided hardware. Use a little blue Loctite on the bolt threads to prevent them from vibrating loose.
Step 4: Setting the Initial Tension
With the tensioner mounted, it’s time to adjust it. The goal isn’t to make the chain banjo-string tight—that will destroy your bearings. You need to allow for proper slack.
Check your owner’s manual, but a good rule of thumb for the Outlaw 90 is about 1 to 1.5 inches of total up-and-down play in the middle of the chain’s bottom run. The tensioner’s job is to manage that slack, not eliminate it.
Adjust the tensioner’s spring or position so that it gently pushes the chain upward, taking out the excessive sag but still allowing for that crucial amount of play.
Step 5: Final Checks and Torquing
Don’t skip the final inspection. Rotate the rear wheel by hand several full rotations. Watch the chain as it moves over the tensioner roller. It should be smooth, with no binding or jumping.
Feel the tension as you rotate the wheel. It should remain relatively consistent. If you find a tight spot, your chain or sprockets may be worn unevenly.
Finally, re-install any guards you removed. Lower the ATV off the stands and give everything one last look. You’ve just completed the how to polaris outlaw 90 chain tensioner install process!
Avoiding Pitfalls: Common Problems with Polaris Outlaw 90 Chain Tensioner Install
Even a straightforward job can go wrong. Here are the most common problems with polaris outlaw 90 chain tensioner install that we see at the shop, and how you can easily avoid them.
Mistake #1: Over-Tightening the Chain
This is the cardinal sin of chain maintenance. A chain that is too tight puts immense stress on the wheel bearings, the countershaft bearing behind the front sprocket, and the chain itself. It will cause rapid, catastrophic wear.
Remember: The tensioner is there to control slack, not eliminate it. Always ensure you have that 1 to 1.5 inches of free play. The suspension needs that slack to be able to move freely.
Mistake #2: Incorrect Tensioner Placement or Alignment
Placing the tensioner too close to either sprocket can cause issues. If it’s too far back, it won’t be effective. If it’s too far forward, it can interfere with the chain’s path onto the front sprocket.
Even more important is alignment. If the roller isn’t perfectly parallel with the chain, it will try to push the chain sideways, causing noise, roller wear, and potentially derailing the chain—the very problem you’re trying to solve.
Mistake #3: Ignoring Chain and Sprocket Condition
A new tensioner is not a magic fix for a worn-out drivetrain. If your chain is stretched (look for stiff links) or your sprocket teeth are hooked and sharp like shark fins, a tensioner will only be a temporary band-aid.
Before you install the tensioner, inspect your chain and sprockets. If they are worn, replace them as a set. Putting a new chain on old sprockets (or vice-versa) will cause accelerated wear on the new component.
Post-Install Care: Best Practices for Your New Setup
Your work isn’t done after the install. Following these polaris outlaw 90 chain tensioner install best practices will ensure your new setup lasts for years. This is all part of a good maintenance routine and care guide.
Regular Cleaning and Lubrication
A clean, lubed chain is a happy chain. Use a quality chain cleaner and a soft brush to scrub away dirt and old gunk. Wipe it dry and apply a fresh coat of high-quality chain lube specifically designed for O-ring or X-ring chains.
Periodic Tension Checks
While the tensioner is automatic, you should still check your chain slack before every few rides. As the chain wears, it will stretch slightly, and you may need to make minor adjustments to the main axle tensioners to bring it back into spec.
A Note on Sustainable and Eco-Friendly Maintenance
Being a responsible rider extends to our maintenance habits. A sustainable polaris outlaw 90 chain tensioner install and care routine is easy to adopt. When cleaning your chain, use a drip pan to catch runoff and prevent chemicals from seeping into the ground.
Consider using a high-quality, biodegradable chain lube. These products work exceptionally well and are much kinder to the environment. An eco-friendly polaris outlaw 90 chain tensioner install mindset also means properly recycling your old metal parts, like a worn-out chain or sprockets, instead of just tossing them in the trash.
Frequently Asked Questions About Your Outlaw 90 Chain Tensioner
How much slack should my Polaris Outlaw 90 chain have?
The ideal chain slack is typically between 1 and 1.5 inches of total up-and-down movement, measured at the midpoint of the lower chain run. Always confirm with your owner’s manual, but this range is a safe and effective standard for most off-road machines.
Can I install a tensioner on a stretched or worn-out chain?
You can, but you shouldn’t. A tensioner cannot fix a chain that is already worn beyond its service limit. It will provide a false sense of security while the worn chain continues to damage your sprockets. It’s always best practice to install a tensioner with a chain and sprockets that are in good condition.
My new tensioner is making a whining noise. Is this normal?
A slight whirring sound from the roller is normal, especially when new. However, a loud whining or grinding noise often indicates a problem. Check that the roller is perfectly aligned with the chain and that its bearing spins freely. Also, ensure the chain itself is clean and well-lubricated.
Do I need to drill my swingarm to install an aftermarket tensioner?
Almost always, yes. The stock swingarm on the Polaris Outlaw 90 does not come with pre-drilled mounting points for a tensioner. The process is simple, but it’s vital to measure carefully and ensure correct placement before drilling.
You did it! By taking the time to tackle this project yourself, you’ve not only saved money but also made your young rider’s ATV safer, more reliable, and better performing. Remember the golden rule: never over-tighten the chain. Keep it clean, keep it lubed, and it will serve you well.
Now get those tools cleaned up, gear up, and get back out on the trail with the confidence that comes from a job well done. Ride safe and have fun!
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