Polaris Primary Drive clutch 850 XCR, Assault, VR1, RMK, Pro, Switchback, XC, Khaos, Matryx, models 2019-24 all options replaces 1323613 1323614 1100-0379

- 2 year Warranty / rated and tested to 320HP / Precision Balanced
- Electric Start compatible, just bolt your stock ring gear onto this clutch.
- 3.0 lbs lighter than a OEM Ski Doo clutch. Center of mass is considerably closer to the motor and the centerline of the crankshaft. This
provides
superior throttle response, faster revving, allowing for lower engagement without hesitation and resulting in better applied traction.
- Used exclusively by MCB on all their personal and shop sleds
- Considerably smoother than any other clutch we have ever used.
- More torque sensing than an OEM clutch. Senses track spin and overall track load and makes seem less adjustments, holding constant RPM. Low end
sensing has an almost traction control like feeling.
- Excellent deep snow, take off and load sensing!
- Considerably less sensitive to snow conditions than an conventional flyweight clutch!
- Easily tuned. Weights can be changed trail side with a 36mm socket and the holding tool (sold separately). The face cover plate is not under any
spring load, this allows weight changes to be made in minutes with a flat bladed screwdriver. The spring cup / retention design is identical to a
Ski Doo design with the addition of a much better spring and spring cup guide tower for easy assembly.
- Very simple, yet the most effective clutch we ever used or tested! 50% less moving parts as compared
to OEM clutches. No flyweights. no rollers, no thrust washers, No arms. Weight adjustable sliding blocks have constant leverage at all shift points
/ speeds as compared to the exponential leverage loss OEM flyweight designs! Simply the best, most durable easily tunable clutch we have used or
tested in our 26 years of business and 40 years of snowmobiling!
Available for almost all Arctic Cat, Polaris, Ski Doo and Yamaha models. Call the tech line with questions or applications.
- For Arctic Cat's the clutch comes with a new bolt.
- This clutch does require it's own puller which will be a drop down option to purchase at checkout.

Replaces Your stock Polaris clutch (1323088, 1322085, 1322796, 1323209, 1323210) directly, same belt, no adjustments needed to the secondary clutch.

JANUARY 2025 - Polaris 850 PB80 Primary Clutch Base Calibration testing has been finalized
MCB has completed the last 4 full days of testing the new PB80 primary on our in-house Polaris 2023 Switchback Assault with 1.352” Cobra.
Multiple tests occurred in semi-controlled conditions. Northern Michigan, 15-20 degrees, hard pack trails and field testing in fresh 10-12” snow over an established base.
Day 1: MCB Sled baseline in OE condition. Comparison machines were 2022 XC 137” and a 2022 Switchback Assault with 1.5” track and gearing changed to 2023 Assault 1.352” track specs. In OE stock configuration all three sleds acceleration was very comparable. The MCB test sled would accelerate slightly stronger on top end but we attributed this to the Assault gearing with the 1.352” track. All three machines would transmit power from standing stop equally well however the MCB sled showed a slight advantage after 50 MPH. These tests were repeatable and allowed us to proceed. (results for hard pack trail and field testing)
Day 2 : After installing the new PB80, the MCB sled felt significantly smoother and then consistently pulled 2.0-2.5 sleds in the critical 0-40 mph testing (hard pack trail). We were seeing more like 3.0-3.5 sled lengths 0-40 in field testing with lose snow. We attribute this again to the lower smoother, almost traction control like features of the PB80. Further, these tests showed the same slight advantage after 40 mph. The conclusion here was typical for the PB80 design in that superior low engagement, without hesitation or bog is a trademark of this and seems amplified in this application. The PB80 applies the available power so much smoother and efficiently, it does not allow the track to disengage the snow as much as a conventional flyweight clutch which then immediately shifting into high gear, only to have to pull back once the track catches up with the ground. It functions almost as a modern traction control. No significant changes were noted in backshift vs. stock. We then tested Deep snow conditions and noted this application performed significantly better as well. With significantly lower engagement and moderated torque, we noted how the PB80 allows the machine to come up on the snow with ease. Casual cruising occurs effortlessly and with very little throttle input. Again, in deep snow field testing the 0-40 separation was even more significant 3-3.5 sleds.
Day 3: Testing began with installing the new Tri-roller spider and helix. Employing the exact same angle and spring as stock (58/44 .36”) we simply changed to the Tri-roller set up. The upshift was ever so slightly improved over the stock set up. The backshift seemed somewhat improved but neither significant nor quantifiable. Clearly this merits further testing with steeper angles on Tri-roller set up.
Next testing will be the SLP head, then head and SLP single pipe with combinations of the steeper Tri-roller helix, stay tuned.
MCB is proud to announce that these new PB80 clutches are now available for all Polaris 850’s, 850 Boost and 9R models, $699.95.