How To Make A Polaris Predator 90 Go Faster

Is your young rider starting to get a little bored with their Polaris Predator 90? You’ve seen it happen. At first, it was the most exciting machine on the planet, but now they’ve mastered it and are begging for a little more zip. You know the ATV has more potential locked away, but you’re not sure where to start.

You’ve come to the right place. We know that feeling well here at FatBoysOffroad. That little 90cc two-stroke is a fantastic starter quad, but it comes heavily restricted from the factory for safety. The good news is that unlocking its true performance is a classic DIY project.

This comprehensive guide promises to walk you through exactly how to make a polaris predator 90 go faster, from simple, free adjustments to full-on performance upgrades. We’ll cover the essential steps, the tools you’ll need, and the critical safety checks to ensure your rider has more fun without compromising safety.

Before You Start: Safety First and Setting a Baseline

Before we even pick up a wrench, let’s talk about the most important part of this whole process: safety. Adding speed and power means we also need to double-down on safety protocols and pre-ride checks. More speed means things can happen faster.

First, ensure the rider always has the proper gear: a DOT-approved helmet, goggles, gloves, over-the-ankle boots, and long pants. No exceptions. Second, these modifications are intended for riders who have demonstrated competence and control at stock speeds, and should only be used on private property or designated riding areas—never on public roads.

With that covered, let’s check the machine itself:

Brakes: Are both the front and rear brakes working perfectly? Squeeze the levers and press the pedal. They should feel firm, not spongy.
Tires: Check for proper air pressure and look for any cracks or damage.
Chain & Sprockets: Is the chain properly tensioned (about 1 inch of slack)? Are the sprocket teeth in good shape and not worn into sharp points?
Baseline Speed: Before you change anything, get a baseline top speed. Use a GPS speedometer app on a phone to get an accurate reading on a flat, straight path. This helps you measure your success!

The Easiest Wins: De-Restricting Your Predator 90

Polaris built several limiters into the Predator 90 to keep speeds down for absolute beginners. Removing these is the first, most effective, and cheapest step in our how to make a polaris predator 90 go faster guide. You’ll be amazed at the difference these simple tweaks make.

Step 1: Adjust the Throttle Limiter Screw

The most common restrictor is a simple screw on the throttle housing on the handlebars. This screw physically stops the thumb throttle from being pushed all the way, limiting how much the carburetor slide can open.

To adjust it, you’ll typically need a flathead screwdriver and a small wrench. Loosen the locknut around the screw, then back the screw out a few turns. Have the rider test it to see how it feels. You can back it all the way out for full throttle travel, but we recommend doing this incrementally as your rider gets used to the increased response.

Step 2: Remove the Exhaust Restrictor

Tucked away inside the exhaust header pipe (where it bolts to the engine cylinder) is often a small metal washer or plate with a tiny hole in it. This plate severely restricts exhaust flow, choking the engine’s power.

Let it cool! Make sure the engine and exhaust are completely cold before you begin.
Unbolt the two nuts holding the exhaust pipe to the engine cylinder.
Gently pull the pipe away. Look inside the end of the pipe you just removed. You should see the restrictor plate tacked in place with a small weld.
Using a Dremel with a grinding bit or a long, sturdy flathead screwdriver and a hammer, carefully break the small weld holding the washer in place. It should pop right out.
Ensure no debris is left in the pipe, replace the exhaust gasket if it’s damaged, and bolt the pipe back on.

Step 3: Disconnect the CDI Rev Limiter Jumper

Many Predator 90 models have a rev limiter built into the CDI (Capacitor Discharge Ignition) box. This is often controlled by a simple wire jumper. Look for a green wire near the CDI box that loops back into its own connector, effectively creating a closed circuit.

Simply unplugging this jumper from itself removes the rev limit, allowing the engine to spin to its full potential RPM. This mod is most effective after you’ve done the exhaust and airbox mods, as the engine needs to breathe better to take advantage of the higher revs.

How to Make a Polaris Predator 90 Go Faster with Bolt-On Upgrades

Once you’ve de-restricted the quad, you can move on to parts that actively add power. These are the most common how to make a polaris predator 90 go faster tips for those looking for a real performance jump. The key here is to think of the engine as an air pump—the more air you can get in and out, the more power it makes.

Upgrade the Exhaust System

That stock exhaust is designed to be quiet and restrictive. An aftermarket performance exhaust, often called an “expansion chamber” for a two-stroke, is designed to maximize power. It uses sound waves and pressure to help pull more air/fuel mixture into the cylinder and scavenge burnt gases out more effectively.

Look for brands like FMF, Pro Circuit, or other ATV-specific exhaust builders. This single upgrade can provide a significant power boost, especially in the mid-range and top-end. This is one of the biggest benefits of how to make a polaris predator 90 go faster, as it really wakes the engine up.

Improve Airflow and Fueling (Air Filter & Re-Jetting)

Now that the exhaust can flow out better, you need to get more air in. Replace the restrictive stock paper air filter and airbox lid with a high-flow foam or cloth filter (like a Uni or K&N style). This allows the engine to breathe much more easily.

IMPORTANT: Any time you change the exhaust or the air filter, you must re-jet the carburetor. The “jet” is a tiny brass nozzle inside the carburetor that meters fuel flow. More air requires more fuel to maintain the correct air/fuel ratio. Skipping this step will cause the engine to run “lean” (too much air, not enough fuel), which can lead to overheating and catastrophic engine failure. You will need to buy a jet kit for your specific carburetor model and install a larger main jet. A “plug chop” test is the best way to confirm your jetting is correct.

Clutch and Gearing Modifications

Power is useless if you can’t get it to the ground effectively. The Predator 90 uses a CVT (Continuously Variable Transmission). You can tune its behavior with different parts:

Lighter Rollers: The weights in the front variator control how quickly the transmission “shifts” into a higher gear ratio. Lighter rollers will make the engine rev higher before shifting, keeping it in the powerband longer and improving acceleration.
Stiffer Contra Spring: The large spring in the rear clutch assembly also affects shifting. A stiffer spring will also help keep the engine in a lower gear ratio longer.
Sprockets: You can change the final drive ratio by swapping the front or rear sprockets. A smaller front sprocket or a larger rear sprocket will increase acceleration but lower top speed. A larger front or smaller rear will do the opposite, increasing top speed at the expense of low-end grunt.

Common Problems and Best Practices for a Faster Predator 90

As you modify your ATV, you might run into some hiccups. Addressing the common problems with how to make a polaris predator 90 go faster is key to a successful project. Here are a few things to watch for.

Engine Bogging: If the engine hesitates or bogs down when you give it throttle, your carburetor jetting is almost certainly incorrect. It could be too rich (too much fuel) or too lean (not enough). This requires patience and testing different jet sizes.
Loss of Low-End Power: Sometimes a high-RPM exhaust pipe can sacrifice a little bit of power right off the line. This can often be corrected with clutch tuning (lighter rollers) to get the engine revving into the pipe’s sweet spot faster.
Increased Wear: More power means more stress on parts. Following a diligent how to make a polaris predator 90 go faster care guide is essential. Check your chain tension, sprocket wear, and engine oil (if it’s an oil-injected model) more frequently. Use a high-quality two-stroke premix oil to protect your engine’s internal components.

One of the most important how to make a polaris predator 90 go faster best practices is to change only one thing at a time. Install the pipe, then test. Get the jetting right for the pipe, then test again. Then change the air filter and re-jet again. This helps you isolate any problems that arise.

The Sustainable Approach to Performance

It might sound odd, but there is a way to think about a sustainable how to make a polaris predator 90 go faster project. An efficiently running engine is a more powerful and cleaner engine. When you perfectly tune your carburetor’s jetting, you ensure that fuel is burned as completely as possible.

This not only maximizes power output but also reduces wasted fuel and harmful emissions. A poorly tuned, smoky two-stroke is inefficient. A crisp, properly jetted two-stroke is a testament to good tuning. Using high-quality, low-smoke two-stroke oil is another part of an eco-friendly how to make a polaris predator 90 go faster strategy, minimizing the environmental impact of your fun.

Frequently Asked Questions About Making a Polaris Predator 90 Faster

How fast does a stock Polaris Predator 90 go?

A stock, restricted Polaris Predator 90 is typically limited to around 15 mph. After removing the basic restrictors (throttle screw, exhaust washer, CDI jumper), you can expect speeds in the 25-30 mph range, depending on rider weight and terrain.

Are these modifications safe for my child?

That depends entirely on the rider’s skill level, experience, and the level of adult supervision. Power should always match ability. We strongly recommend making changes incrementally and ensuring the rider is comfortable and in control before adding more power. Safety gear is non-negotiable.

What is the very first thing I should do to make it faster?

Start with de-restricting it. Adjusting the throttle screw and removing the exhaust washer are free, provide the most significant initial gains, and are what the machine was designed to do without those limiters. Master that speed before spending money on parts.

Do I absolutely have to re-jet the carburetor after installing a pipe?

YES. 100%. We can’t stress this enough. An aftermarket pipe flows significantly more air. Without adding more fuel via a larger main jet, the engine will run lean, get extremely hot, and likely seize, destroying the piston and cylinder. It’s the most critical step after installing a pipe or high-flow air filter.

Unlocking the potential of a Predator 90 is a rewarding project that can grow with your young rider’s skills. By starting with the basics, focusing on safety, and tuning correctly, you can turn that tame starter quad into a machine that will keep them smiling for years to come.

Now get out to the garage, wrench safely, and have a blast on the trails!

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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.