Ski-Doo Bulletin: Vibration Damping Clutch Technology

salmonbum · Mar 24, 2017

Why do they need to have a special cvt cover and a "fan" to help reduce heat? Maybe I'm not thinking clearly, but wouldn't it make sense to SOLVE the root cause of the heat..... to reduce the heat? Putting a fan on it is, again..... a band aid.

Insaneboltrounder/sjohns · Mar 24, 2017

Wow.... all this new clutching tech and we are still smoking off belts. Why is this not and issue on 270 hp yamaha turbo apexs?

winter brew · Mar 24, 2017

geo said:
Heck of a good idea Brew. Do you use that tech to do your testing at work?

In '12 I used my Snap On adjustable timing light to catch the wobble induced into the rubber mounted jackshaft on my Cat from the primary. That one was only out .009". It was scary eye opener.
Went through 6 primary's on the shelf at the dealer to find the best one in all dimentions and warrantied my original. Allowed me to finish the year on one belt.
Apples to oranges though.

Yes, it's amazing what a high speed camera can capture. It would have to be in a lab environment to do it right, there may be things happening on the snow that are tough to replicate in a lab.

Trolltech · Mar 24, 2017

silver_bullet said:
I have scattered 4 belt with in 475 miles. I am still on my 5th belt with 380 miles on it. I vented my clutch area and tore all of the foam out and cut the clutch cover bottom area off. I ride hard but stop and melt snow on my clutches just so I don't scatter another one. Its not easy to cut the cords out when a belt goes. I just ordered a floating secondary. I hope it works. Friends on poo's can't believe how hot my clutches get. I wish we had their clutching. 30 minutes max of hard riding and I stop. Its embarrassing to always be cooling my clutches down with snow and making stops for 2 850's in our group. With that said they run really good and are great to ride. I just wish it wasn't in the back of my mind while riding steep and deep in the tree's!!!! I hope there is a fix soon. With a 18 already snow checked it won't be easy to sell with out it!!!!!!!!!!!

http://www.hotrodsledshop.com/hotrodslshal.html

Norona · Mar 24, 2017

SidewaysInto3rd said:
What sort of proof would you like ? lol

a notarized letter ?
pictures of my blown belts ?
want to call my dealer and verify that I actually own an 850 ?

:behindsofa:

How about a DNA test from my handlebars or belt chunks ... that will be irrefutable evidence that I indeed own an 850 ... just name it and i'll get it for ya bud

Or maybe you can just ask your favorite skidoo back country expert the one and only Mr. DAVE NORONA aka my old next door neighbor .. he'll concur that I actually do exist

He does exist and have an 850 and has had a nightmare season in between some sick days. Although quite a "drama queen" I feel for Payam and his issues this winter, working towards helping him out as the riders experiencing issues this winter, it sucks but they are working hard on those with a issues. Payam you know I am being funny with the drama queen bit :face-icon-small-hap

caper11 · Mar 24, 2017

So if you have a "in" with a ambassador sideways, how come your sled was not taken and studied by engineers? Its easy to get a loaner sled if your dealer and BRP stepup, and your sled seem to be the best candidate for a inspection. You have been the loudest on all three forums about your issues to the point where "drama queen" is not far from truth. Please do not take what I just said to heart, im not trying to be mean or rude, but your fustrations has fallen fall on ears that listen, and I hope it was heard loud and clear in Quebec.

SidewaysInto3rd · Mar 24, 2017

caper11 said:
So if you have a "in" with a ambassador sideways, how come your sled was not taken and studied by engineers? Its easy to get a loaner sled if your dealer and BRP stepup, and your sled seem to be the best candidate for a inspection. You have been the loudest on all three forums about your issues to the point where "drama queen" is not far from truth. Please do not take what I just said to heart, im not trying to be mean or rude, but your fustrations has fallen fall on ears that listen, and I hope it was heard loud and clear in Quebec.

lol .. that's not how it works.

its been a tough season ... but this is hands down the best sled i've ever ridden and the love/hate rollercoaster ride has been ... interesting.

yes I bitch and moan a lot ... i guess I have too much time on my hands ... weather or not BRP reads this stuff is beyond me. I'm pretty sure the same issues are being had by more connected people like alford and custer and im sure their sleds have been looked at by the engineers

people like me can only try to make some of the issues better, and leave the rest up to brp to sort out.

I don't mean to use these forums as a way to reach out to BRP, just as a way to find solutions or improvements while we all wait for the real fixes to come in... sometimes my patience runs thin and i need to vent ... and then i get my sled back and go for a ride and happy again .. Yesterday was a good good day !

Frankly I'm surprised Dave still talks to me ! hahaha

Chadly · Mar 24, 2017

I think there are a ton of drama queens that bought 850's. I will bash Doo when needed because of the amount of money I have spent on sleds the past 5 years. I have rode 35 times this year blowing 2 belts. Now until I ride with someone else that shows me otherwise I spent all season making people looking silly on my stock 850's that had Tom's and Diamond Cans on them. These sleds rip beyond belief. They are first year so they are going to have issues. What sled hasn't? If you had to pull out a six year loan to buy your sled, buying a first year that might be in the shop for a week probably wasn't a good idea. Perhaps you should have gotten a loan to buy one of my used sleds that has been through the ringer ?

motoracer5 · Mar 24, 2017

Spending a $1000 a month on belts is dramatic? One friend has got quite a few warrantied (4 maybe) But 2 others guys did not get that lucky. The sleds are awesome, but everyone I know that rides them hard nukes a belt in 200-500km. One not properly broke in blew in 30. It's really not fun to deal with

ntm_08 · Mar 25, 2017

Talked with B.Rasmussen and he is also having issues. And in lower altitude even more.

If the 2018 updates fix the problem, then nothing other then those parts should be offered to the 2017 G4's. And why is it not done yet? Is the issue still not figured out yet? Should people preorder sleds before this have been fixed?

Someone told me of all the fixes for 2018 the lower gearing is the biggest help. A sled with 165hp and that low gearing, everyone understands that this is a patch fix. Its like riding a gearing for a 100hp sled.

mountainhorse · Mar 25, 2017

With SOME sleds having big issues and SOME sleds having no belt issues, even when run hard.... It would lead me to believe that this is more related to manufacturing consistency (or lack thereof) that is causing issues.

Yes, the Active vibe reduction is a great idea.... and when you wrap your head around it, it makes sense...But there are many variables that can throw it "out of whack"....

Is this causing the belt issues... No one knows that answer YET....

But I can say this, from 30+ years as a professional in the mechanical trades.... This systems complexity and its obvious reliance on strict adherence to tight manufacturing tolerances certainly could complicate things... and inconsistencies in manufacturing this system in EACH sled has a higher probability of variance than a less complicated "typical" CVT system..... When It's good... Its good... but if something is slightly 'off'.... I believe (IMO) that this new system will exacerbate belt life problems.

It is not just potential variance of the clutch specs/function and the vib reduction 'system'... it could also be a huge variety/combination of things from balance of the flywheel, to the balance of the clutch, to precise phasing of the crank, to motor-mount consistency in manufacture, to clutch component smoothness, to slight ignition/injector timing, to slight variation in Myriad tolerances required to keep this particular machine working in UNION with the vib reduction 'system'.

What ever is being counteracted needs to be as consistent as the system that actually DOES the counteracting.... for the system to function, it is a balancing act.

And, as I've said before... the clutches should not be making heat like they do... and from the accounts that I've listened to or read about.... the clutches do run hot on the G4-850's new CVT system...And this new tech, which may reduce Vibes... may also, inherently, increase belt temps.

Adding a cooling fan, airflow, and a belt that is more tolerant to higher temps is a nice 'treatment'... though I keep thinking that the heat should not be generated there in the first place (the 'cause') if the drivetrain is expected to function efficiently and get the power to the track.

It is possible that some mfg tolerances were let slip on the sleds that are eating belts...Yes.

No.... It is NOT the majority... it is significant however IMO... and NO... those that ARE having issues are not drama kings/queens... and YES, for those of you that have 1500 miles on your 2017 G4-850 original belt, that is what you SHOULD be able to expect on a $12,000.00+ sled with belts that cost as much as they do.

"BLOWING A BELT" (catastrophic failure) is SUPER hard on the engine/drivetrain/chassis. And we all know what a blown belt can mean when you are on a big pull in steep area, or a sidehill in a high consequence zone.

Also, from all accounts I've heard, BRP is very aware of customers sleds that are having issues. If fixing those sleds was an easy undertaking... they would be able to diagnose and remedy the problem, not just throw 'good will' belts at the situation.

I would really like to see, on the belt eater sleds... if the clutch is machined true, that this solves the issue... and thus could either eliminate that the vib reducing offset system is causing the problem or the issue lies elsewhere... and if the rider & sled can live with any additional vibe that may show up.

Also for ME.... 'the proof will be in the pudding' for 2018 IF... IF... actual recorded data of CVT temps are reduced and there are not Significant number of G4-850 owners that are having CVT issues and belt issues all but disappear.

.

Matte Murder · Mar 25, 2017

Belts are wear items. Expecting a belt to last 1500 miles isn't reasonable. Ridden hard in deep snow in the mountains I expect to lose some performance at about 600 miles on an XM. I can run belts much longer and they don't ever grenade on my XMs but even 1000 miles per belt with no performance loss is unreasonable.

geo · Mar 25, 2017

Mountainhorse. Speaking of "and when you wrap your head around it" and "precise phasing of the crank", have you looked into when and where this "event" BRP is trying to contain actually occurs?

Do you know where in relation to TDC on the PTO cylinder the high spot-low spot (or maybe talk closest to piston and furthest from piston) the clutch is indexed at?
You know, eliminating cyclical, and only looking at side to side working on side to side stuff.

nickbeann · Mar 25, 2017

Well yesterday I took a better peak and for more precise measurements removed my bottom pan and put a dial indicator as close to 90 degrees as possible to the fixed sheave on the bottom side of the sled.
The runout was .028 with the highest runout being approx 1" counter clockwise from the timing mark line on the fixed sheave after checking numerous times.
Not sure if this is making a difference in making my sled eat more belts than normal, just throwing the info out here to help.

boondocker99 · Mar 25, 2017

rkm said:
I keep reading people say this was in testing for years and years before production. If that was the case, it would have been patented.

Well a *little* research suggests otherwise...

The average time it takes to obtain a patent from the patent office at this time is about 32 months or a little under 3 years.

mv183 · Mar 25, 2017

https://youtu.be/_ePTZezN_Iw
For all the G4 and P-drive haters out there

SidewaysInto3rd · Mar 26, 2017

Matte Murder said:
Belts are wear items. Expecting a belt to last 1500 miles isn't reasonable. Ridden hard in deep snow in the mountains I expect to lose some performance at about 600 miles on an XM. I can run belts much longer and they don't ever grenade on my XMs but even 1000 miles per belt with no performance loss is unreasonable.

lol .. my last belt worked for 80 miles

is that reasonable ?

rulonjj · Mar 26, 2017

SidewaysInto3rd said:
lol .. my last belt worked for 80 miles is that reasonable ?

One belt for every tank of gas is perfectly reasonable with the 30% quicker throttle response and 10 more hp.

salmonbum · Mar 26, 2017

So it seems, as I have mentioned, Ski Doo is just doing some band aids to fix the belt blowing issue. The minor fixes will help, but it will not be 100%. I still believe the main cause of heat is alignment. Many have posted how buddies with Cats and Poos do not have an issue withe excessive heat. Now lets think of something they have in common...... the secondary floats. Everyone I know, including the personal sled I run in Michigan, that has modified the QRS to float DO NOT BLOW BELTS. Floating the secondary is the best band aid you can do. Floating +/-3mm will make up for all your MFG tolerances and reduce heat by leaps and bounds.

Ski Doo..... Get your head outta your ***. Just put the floating QRS kit you ALREADY MAKE on the damn sled instead of clutches with fins, complex cover, etc....

mountainhorse · Mar 26, 2017

Not sure if a floating secondary would be compatible with the built-in wobble of the pDrive on the G4-840's though???

.

Ski-Doo Bulletin: Vibration Damping Clutch Technology

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