towerrigger
Active VIP Member
Interesting that they don't list anything for clutch parts right now on the parts website for the 18's. They are also listing a shim for the motor mount with all the slop in it. 
18 Clutch Specs
- Thread starter Rotax_Kid
- Start date
Yep that is the brp sloppy engine mount fix for 2018, a shim kit. Ironically enough of all the 850's through my shop not all have this "wobbly clutch" issue. However they all have the sloppy engine mount issue, which is easily fixed, then you can begin tuning the clutches.
Deano
Mad Motorsports
Deano
Mad Motorsports
towerrigger
Active VIP Member
So your saying not all of the 850's have the offset back sheave?
snopro
Active VIP Member
They all do. Except for the few that have already machined there's true.
Caper11
Active VIP Member
I actually heard that machining the sheave true, had a negative effect on performance.
snopro
Active VIP Member
You know I'm an old school guy that used to race at a pretty competitive level as far as sleds go. I was always taught by really bright people whom I would have no business even carrying their notebook that truing everything you possibly can will help make power. If Rotax is building motors with true running crankshafts then I can only assume that anything hanging off the end of it that runs true would help not only performance but engine life? I just cant get my head around this wobble design.
kanedog
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Please explain how a true running sheave has a negative effect on performance?
Caper11
Active VIP Member
Whats the purpose of the runout in the first place?
I encourage you to research Vibration and Resonance especially in engines which produce "Torsional Vibration" and how it affects the crankshaft.
I encourage you to research Vibration and Resonance especially in engines which produce "Torsional Vibration" and how it affects the crankshaft.
handyandy
Active VIP Member
I always thought the wobbly clutch was just a joke. Was it actually machined that way intentionally? Sounds crazy haha
C of Red
Active VIP Member
Now Doo's have wobbly clutches and suspension... I can't wait to get my '18 wobbly Freeride.
Caper11
Active VIP Member
The Pdrive is not wobbly, its only the fixed sheave that has the induced runout.
towerrigger
Active VIP Member
I still have to think this whole thing was a last minute addition in MY17. With them not having a patent in place, not announcing it when they first released the sled is very unlike ski doo. If it was so good they would want to brag about it. They didn't release the info until guys started machining them straight. What a blunder this whole thing is. Sure hope the aftermarket has a solution.
Caper11
Active VIP Member
Im sure the aftermarket could do something if guys are willing to have a heavier clutch to stop the resonance and vibration.
