When you’re out for a ride, your RZR can feel one of two ways when you hit the gas: you either don’t notice it or it feels sluggish. That’s it. What you don’t notice are the hundreds of factors that go into making your machine drive the way it does—not least of which is your RZR’s primary clutch.
The Polaris primary clutch is the first right at the beginning of your drivetrain. It’s the first thing your engine interacts with before that power actually moves you forward. This makes the primary clutch one of the most important parts of your drivetrain, and it’s incredibly complex. Making changes to the clutch that seem insignificant can have huge consequences to horsepower, torque, and belt life.
Instead of leaving the ins and outs of your primary clutch hidden behind a veil of mystery that can’t be understood by the casual rider, let’s break it down so you know how this key piece of equipment does what it does.
The primary clutch on Polaris UTVs is what’s known as a CVT clutch. CVT stands for “Continuously Variable Transmission,” which basically means it changes gears without changing gears. Hang with me for a minute here.
Most cars shift through different gears as you accelerate. You start in first gear and accelerate easily, but soon your RPM climbs too high and it’s harder to accelerate. That’s when you shift into second. With each shift, your acceleration stops for a moment and your RPM drops back down into the optimal range for your vehicle’s acceleration. And then you start the process again.
A CVT clutch changes its shape so the clutch drive belt doesn’t have to shift. That means it can stay in the optimal RPM range all the way until you hit the mechanical limitations of the clutch.
That’s the main advantage of Polaris’ primary clutch setup—you get continuous power when you lay on the gas. But the mechanics that go into that process are a little more complicated. If you know what you’re doing, you can take advantage of those mechanics to boost performance.
Let’s get into the juicy innards of the Polaris primary clutch, where you’ll find parts that spin, parts that flop, a bunch of aluminum, and a big ol’ spring.
The primary clutch looks kind of like a couple dinner plates smashed together with some extra hardware on the backside of one. Those dinnerplates are the sheaves. They’re what the belt rides on. It rides higher or lower on the sheaves depending on how far apart (open) or how pushed together (closed) they are.
When your foot is off the gas, the clutch is fully open because the primary clutch spring holds it open. With the clutch fully open, the drive belt doesn’t move or transfer power to the secondary clutch, transmission, or anywhere else in the drivetrain.
As soon as you touch the gas, the RPMs rise and the clutch starts to close. This makes the two sheaves move closer together and pinch the belt. That pinch is what starts driving the belt and delivering power to the rest of the machine. This is where the magic happens. As the sheaves move closer together, the belt moves further out on the clutch, like a chain on a bike moving to larger gears. Except, because the clutch is CVT, that change is smooth.
The trick is finding the engine RPM that outputs the highest torque and horsepower. Finding the right balance between the clutch spring and clutch arms can help you maintain that RPM sweet spot.
The primary clutch spring is trying to keep your clutch open with all its might. The clutch arms fight against the spring by using centrifugal force to try to close the sheaves. Clutch arms at different weights change the rate that these sheaves close.
There are lots of little details that help a RZR primary clutch run smoothly. The roller material, roller bushings, and arm bushings are all crucially important. Polaris has those details perfected, but where we see room for improvement is the balance between the spring strength and arm weight.
That’s where SuperATV Clutch Kits come in.
When we make a clutch kit for Polaris vehicles, all we do is change the spring and clutch arms out for a different set. Sounds simple, right? It’s not!
Changing out the spring for a different one makes big changes to your clutch’s behavior. If it’s too stiff, your clutch stays open too long, which means your RPM will be over the optimal range before you even start moving. If it’s too soft, your clutch will close quickly, so you might never hit the optimal RPM range at all.
We get close to the RPM sweet spot by trying out different springs and measuring the RPM curve. After we get a good candidate, we fine-tune it with the clutch arms.
Our clutch arms have three separate weight points along them. This lets us be very precise. After we get the spring we think we need, we slap some weights onto the clutch arms and give the machine a pull on our in-house dyno. The dyno (short for dynamometer) measures horsepower, torque, and RPM over time.
With data from the dyno, it’s easy to see when the machine reaches optimal RPM—where HP and torque are highest. And it’s easy to see how long it stays there before over-revving and eventually hitting the rev limiter.
The cool part is that because of the three weight locations on our clutch arms, we have a lot of control. If it’s engaging too late, put an extra half gram nearest to the pivot point. If it over-revs too early, pull some weight off the outmost spot. If the torque dips in the middle, then we can add a little weight to the middle. We have incredibly precise control.
Once we dial in a weight combo that keeps the machine in the optimal RPM range for as long as possible, the clutch kit is finished.
You might be wondering why clutch kits exist at all. Why doesn’t Polaris just get the perfect spring and clutch arm balance right from the beginning? The short answer is that Polaris balances their kit for the average rider and doesn’t target overall peak performance for some reason. If you’ve read this far (thanks), you are not the average rider.
We’ve gotten to know so much about the ins and outs of clutches because that’s what it takes to make them better and to cater them to individual riding styles. We have kits that give you more power right up-front for quick torque and acceleration—perfect for mud and rocks. We make kits designed to give you a higher top speed for wide open racing. And then we also make balanced kits like stock but with more horsepower, more torque, and a higher top speed throughout your clutch’s engagement range.
In other words, we make our clutch kits for you. And with a huge variety, you can find the clutch kit that’s perfect for you. If you’re clutch is beyond saving, you can check out our RZR Primary Clutch Assemblies.
40 Comments
I have a 2004 sportsman 700 that was my dads when I got it 3 years ago and I have gotten it running and riden it but noticed it was very jerky so I bought a new belt and removed both clutches with the proper tools and inspected all the sheaves and springs , everything looked good so I reassembled with the new belt and when I run the engine at idle it won’t go into gear and when I start it in gear it moves and I have to shut it do n to stop it, even if it’s idling below 1000 rpm. Ive removed everything again and can’t see anything wrong the primary clutch looke as if it’s disengaged all the way but something is wrong what should I look for thanks
Sounds a lot like you have a belt that’s a little too small which causes it to stay engaged all the time. That would explain why you’re grinding gears trying to get into and out of gear. Plus that’s the only thing you changed so it makes sense. Feel free to try our belt: https://www.superatv.com/polaris-atv-utv-cvt-drive-belt. If you decide to buy it and are still having trouble, you can give us a call and we’ll help you figure out what’s going on. But I’m certain the belt is the issue.
My sportsman 800 did same thing took me forever to figure it out but my problem was the one way bearing in primary
my bike is going into high and low and all while the bike is running and it drives foward with no issue up until it doesnt drop rpms in the motor due to the tranny not shifting idk whats wrong
Hey! It’s hard to say for sure without digging into it, but it sounds like a belt and/or clutch issue, which is probably best case scenario given the cost of a transmission or even transmission repair in most cases. What kind of machine do you have, and is it giving you any maintenance codes?
I have installed one of these kits in my 2015 900 rzr 4. I have 30″ tires and mostly crawl and climb. In low range it reacts perfect when climbing. I do have 2 issues though and maybe you can help. My clutch isn’t disengaging properly and it causes the engine to choke out at some of the worst possible times. Would that be a half gram or so heavy at the weight closest to pivot point? I have struggled finding any information on tuning weights as far as which location does what until I read this post. I would welcome any additional clutch turning info.
I have a 2013 Polaris sportsman 500. I’m having trouble with the “shifting”. It goes into gear fine. When I accelerate, it gets to about 20 mph or so and then the RPMs rise but the speed stays the same. If I let off the throttle then it will “shift” and allow me to go faster. I realize it does not shift but that’s the only way I know to describe it. I would be interested in replacing the clutch with something higher performance but not necessarily right now if that’s not the problem. So far I have changed trans oil and replaced belt. Any advice would be appreciated. Thanks, Jeremy
Hey Jeremy! Unfortunately, we do not currently offer any clutching for the Sportsman ATVs, but it sounds like you’re on the right track. If it’s not in your transmission, it’s more than likely your clutching and/or drive belt. Since this isn’t a product we have dabbled in, you’re going to be better off contacting a dealer or Polaris mechanic for more information in those areas. Thanks for reaching out!
I.have a 1997 polaris 250 trail blazer. I took the cluch plate off to remove starter. When I put clutch plate back on polaris would not start. I took clutch plate back off, started polaris it started fine with no clu Ch plate. I put clutch plate back on. Same thing would not start. ??? Why ?
Hi Rhuedolph, unfortunately we do not offer any quad clutches. Sorry abut that. We appreciate the support!
I have a Artic Cat, wile cat tub side by side.
Vin#4UF15MPV2FT309225.
GOING DOWN HILL I HAVE TO ADD GAS FOR THE ENGINE BRAKE TO WORK… IS THERE A CLUTCH BRAKE MADE TO CORRECT THE PROBLEM???
Hey James, thanks for reading! Unfortunately, we do not currently have a clutch kit for Arctic Cat.
I have a 2009 rzr 800s stock tire size. I don’t seem to get up on rpm. The max I’ve hit is 5600. I can get to 60mph on the road long straight. The spring is white and engages at the correct rpm but wonder if something else is worn out. Haven’t pulled anything yet but did replace belt. Any suggestions on how or what to check before purchasing a new clutch kit. Also note brand new top end great compression.
Hey Phillip, 60 MPH is actually not too far off for the machine you have. 5,600 RPM might be slightly low, but the 600/700/800 hydraulic lifter pushrod engines just don’t rev like the newer shim-under-bucket engines do. The rev limiter on the 800s was 6,750, but that shouldn’t be hit until the machine is running flat-out at its max top speed. Also, on some of the older 800 primary clutches, there is a plastic limiter spacer that keeps the clutch from closing up all the way. This in turn would limit the speed of the machine because it will keep the clutches from shifting to a higher gear ratio. With this being said, we have a few questions. How long have you had this machine, and does it hit a higher RPM in lower gear?
I have a 2019 general 4 1000. Bought it new, and it has always had a bit of a clunk/ click noise when the clutch first engages. Is this normal? I have also increased the tire size to 30”. I would like to upgrade the clutch for durability and improved performance with the larger tires. Which kit would you recommend for general trail riding?
Hey Karl, it sounds like the noise you’re experiencing is pretty typical. It’s usually the helix in the secondary clutch that is making the noise – nothing to be concerned about. As far as a clutch kit goes, for 30″ tires and general riding, pretty much any properly designed kit should work. We would recommend getting an adjustable one just because of the ability to finetune the engagement and shift points. Say, for example, you want to change something later on (ex. raise the engagement rpm 100 rpm for a harder launch off the line), this can easily be done by removing some weight at the heel position on the cam arms. With adjustable clutch weights, that ability is there. With fixed cam arms, it is not. We have a kit that is perfect for this, linked here: https://www.superatv.com/polaris-general-1000-clutch-kit Unfortunately, we are currently out of stock, but if you want to give us a call in the next few weeks to check back on this, we should be able to get you set up. 855-743-3427
Ok so i have a 2003 330 trailboss it only will run about 20mph the belt is new tye trans is fine and full but the primary clutch will only pull in slightly i removed it all the weights arms are free and no binding or broken spring the bike runs perfect nobody can tell me why it only sucks the clutch halves together slightly i want to buy a new primary clutch if it will fix this i dont want to guess thanks if ya know
Thanks for tuning in, Todd! Unfortunately, this isn’t a machine that we work with a lot, but it sounds like the clutch is definitely where the issue lies. Sorry we couldn’t be of more help!
Spider is stuck and does not move freely on our 2020 Sportsman XP. Any ideas I need how to get it moving again? Husband went into mud that was too deep.
Hey Michelle, thanks for reading! My guess is that you’ve more than likely got a broken sprague. However, if you or your husband can call into our tech team, they should be able to get you figured out. Just give us a call at 855-743-3247.
My Polaris Rzr 900 2018 put 30 inch tires and the clutch get. Seems to have good power but if I let off the throttle now it down shifts reallly hard and the belts are getting hot. Never had a belt problem before but now I go through belts like crazy. They usually grenade when it likes to downshift really hard. Any suggestions?
Hey David, there could be a number of things going on here. If you give us a call at 855-743-3427, our tech team should be able to help you troubleshoot the issue. Thanks for the support!
Kevin we bought a used Polaris rzr xp 1000 2017 with 1600 miles hears a sound that came from the secondary Cluch, we put a new secondary Cluch in and the sound went away but it kinda hops at the start and smooths out at a higher speed is this normal
Hey Steve – No, that issue doesn’t sound normal. You’ll want to make sure the clutch is aligned properly and that the belt isn’t slipping. It could also be a clutch weight issue. Thanks for tuning in!
I have a Sportsman X2 700 used for hunting. Currently the working revs seem to be around 4200 and I want to reduce it to around 3500-3700 for earlier upshifts and less noise. Any suggestions?
Hey Neil, unfortunately we do not currently offer any ATV clutches to help you out. Sorry about that. We appreciate you tuning in!
I have a 2016 900s Polaris RZR. I have replaced both clutches. When I release the accelerator, it severely jerks? Is the brake not releasing? Could something need adjustment? I can’t locate problem.
What could be some possibilities and how do I fix?
Hey Kat, it’s more than likely a clutch or belt issue. If you can give our customer service team a call at 855-743-3427, they should be able to help troubleshoot for you. Thanks for the support!
Did you ever figure out what the problem was? Mine is doing the same thing
Hello I have a 2015 rzr 900 4 eps
I’ve purchased your general performance kit CK-1-44.
When the new arms are in they are quite tight there not free moving they stay where ever you lift them. Good or bad . Not going to finish installing kit till I hear from you.
Hey Dean, you should be able to move it by hand. It might take a little bit of muscle, but it shouldn’t be super loose by any means. I’d say if it’s got grease in it, you should be fine. Give us a call at 855-743-3427 and our customer service team should be able to help you get it figured out. Thanks for the support!
I have a 2014 rzr 800 I revived a cloth for a 2009 rzr 800 it fits int 2014 just. Wondering if this will work in my 2014 rzr 800 thanks
Hey Chad, thanks for tuning in! We actually don’t currently offer clutches for the RZR 800, so I’m not sure if this would work.
2016 900s.. Engine brake grabs so hard at low speed in H that it nearly throws you through the windshield. WHY!! Will a new/different helix help?
Hey Kristine! We don’t recommend being in high gear going low speeds. It’s a quick way to burn up your belts and run into other problems. Feel free to reach out to our customer service team at 855-743-3427 for any questions!
ive got a 2015 900 that wears out primary clutches 1 to 2 per year,any reason why they are going bad,we are not hard drivers at all
Hey Robert, thanks for reaching out! A couple of things could be coming into play here. Do you spend most of your time riding in high gear? It could be a matter of staying in low when you’re not really getting on it.
Hi! i have a 2017 Polaris xp 1000 . its been a great machine has roughly 6 k miles . my problem is a belt only lasts us roughly 6 months or if it doe smake it longer it keeps sending the machine into limp mode . wich pulls a check engine code . the codes read a misfire on both spark plugs , ive changed the plugs multiple times and wires etc. i dont think its a spark plug problem . i believe its in the stock clutch . soes this ring any bells ? and what can i do to fix my issue
TY!!
Hey TJ! You are correct—more often than not, the misfire codes are due to the belt slipping. So you’ve more than likely got a worn belt and/or clutch sheaves. The most common reason for premature belt wear is going in high gear at low speeds. Even being in high gear for a small period of time on several occasions can cause premature wear. You’re basically going to want to be in low gear unless you’re staying at constant higher speeds, such as road riding, wide open trails, or desert/sand dune riding. You can check for wear on the clutch sheaves by removing the belt and feeling for grooves that have been worn. Sometimes you can help correct minor wear just by taking fine grain sand paper to them to clean the sheaves up. Feel free to give us a call at 855-743-3427 if you need anymore help!
yes i have a 2013Polaris rzr 900 the issue im having is when im driving and come to a stop its like im driving a stick shift and forgot to push in the clutch it kills the motor then when i start it back up its fine but sometimes its still engaged any thought to this would be appreciated thanks