Polaris Engine Braking Explained
Most of my articles are rather long and you can sometimes get lost in them so I am going to explain this in a simply shorter way, I hope!! LOL
Polaris calls this EBS (Engine Braking System) it consist of two parts, no substitutions a EBS Secondary Clutch and a One-Way primary bearing. However Polaris does use the EBS secondary on several models with a normal two way bearing and those vehicles have more engine braking than the ones with the Rapid Reaction secondary.
To see the EBS secondary click HERE, we sell them. If your secondary does not look like this then you do not have a EBS secondary and would have to have one to get any level of low speed engine braking.
Three levels of engine braking
Least Braking: Any vehicle with a Rapid Reaction secondary clutch and two way primary bearing, you can't add a one way bearing to this and get engine braking, once again you have to have the EBS secondary. So with these vehicles you get engine braking down to somewhere in the 10-15 mph then it free-wheels and you hear a whirring noise which is the primary bearing spinning under the belt, all normal. The vehicles that have this are the most and instead of telling you which do, I will tell you which have the other two levels and if yours is not in those list then you have this.
Some Braking: These vehicles have the EBS Secondary clutch but a two-way bearing, they have engine braking down to about 4-5 mph then free-wheel. You can tap the brake going downhill and get it to engage. How this works is there is what is called a EBS notch in the the removable helix in the back of the clutch. Only the EBS secondary has a removable helix. To see a helix click HERE and the helix on the left in the picture has a EBS notch, the one on the right does not. That would be for someone who wants to remove low speed engine braking for say a racing application. Back to how it works, as you accelerate the secondary rollers run up one side of the helix, when you decelerate it rolls back down the other side and when the roller rolls into the notch it basically slams the secondary clutch closed and forces the belt down in the primary clutch.
Vehicles that have this set up from factory are 08-09 RZR 800 but only 09 built before 10/09 after have do not have the EBS secondary, 2011-2014 RZR 900 XP and XP4 and 2014-2015 RZR 1000 XP and XP4 So since they already have the EBS secondary if you wanted full on EBS all you have to do is add a one-way bearing to the primary. NOT available for the 1000 yet but 900 and 800 can get our new HD One way bearing kit and add it. Click HERE to see those. Make sure you read that tech article before you do this, if you jump a lot you will not want to do this.
Full On EBS, Most Braking: These vehicles have the EBS secondary and a one way bearing in the primary from the factory. Other than the 09 S RZR 800, any vehicle that comes with a one way bearing, those bearings fail rather often. Polaris changed the bearing around 2010 and new one is smaller hence the reason we now have the HD primary bearing kits. The 09 S came with this good bearing and rarely fails. So what the one way bearing does is, it will not turn counter clockwise so when you drop below 5 mph and the primary clutch does not have enough RPM to keep it closed the belt drops down on this bearing and will not roll forward free wheeling like the two way does, it basically locks the clutch to the crank and you get engine braking all the way to you stop.
Vehicles with this are: 09 RZR S 800, 2013 RZR 50" EPS LE Blue Fire in color, 2015 RZR 900 Trail with EPS, 2014-15 570 RZR LE and I don't know the years on the Rangers but it would be the Browning Editions and I think the Hunting on 2015 but do not hold me to that. I am correct about the RZR's for sure. I can always look at your model on the microfiche if you have questions if it does or not so just call. Again on the 800 and 900 RZR that list is correct.
The vehicles we can add full EBS engine braking too that do not have it are the any year RZR 800 and XP 900 and XP4
The vehicles we can add some engine braking to are RZR 800 and year, RZR 570 13 forward, Ranger 900 14 forward
Hopefully this clears some of it up but if you have any questions then feel free to call Todd. Trust me Polaris clutching is confusing and sometimes Polaris throws something that can't be found anywhere on any model or microfiche like the primary on my own Ranger 900 2014 is not on a microfiche anywhere, it does not match anything.