Machine shop may have found the belt problems

[mountainhorse]

That sheave does not run true... no denying that.

What caused it??

Was it delivered that way... or was it the result, as suggested above, of a belt... under load... blowing all of a sudden?



.

 

[fredw]

My rpms never float, tra has been a rock even on the stock 16-174 we had our last ride, if your bouncing rpm on the tra, it's not hard to figure out why.. pdrive was made out to be much better than it is, maybe in a few years I will fell different, but not now

Redline's making new internals they feel will help its performance

The tra was notorious for this exact problem.
The secondary isn't helping the situation either.

 

[rulonjj]

My rpms never float, tra has been a rock even on the stock 16-174 we had our last ride, if your bouncing rpm on the tra, it's not hard to figure out why.. pdrive was made out to be much better than it is, maybe in a few years I will fell different, but not now

Redline's making new internals they feel will help its performance

My aerocharged xm floated around as much as 300 rpm at times. My 850 holds 7900 rpm like it doesn't know any other number. Super consistent.

 

[powdermuncher]

Just got of the mountain after a weekend of testing.

4 sleds 4 different setups.

Hands down the ZRP weights win with the most consistent rpm from 2000 to 5000 feet this weekend pegged right at 8000 temperature from - 18 C to-3 C late afternoon.

The others had stock setups with weight and sea level setups with 951 arms less pin weight for elevation and mine has the SHR set up with the 968 weights. (it is the most finicky for elevation but the clickers are way more effective than on the stock setup -- go figure

If all sleds runs right on 8000 they have the most consistent performance and there is very little difference on an uphill pull in a foot and a bit of powder. The ZRP set up with the 85 GR weight and full load in the bottom and 2 grams in the middle just ran best and more consistent than any of the others.
Clickers are simply not needed on that setup.

One Guy granated a belt so bad it shattered the plastic on the guard and the rubber melted right into the remaining plastic. On my wife sled the steel bottom section in the clutch wears a groove on the fixed sheaf side of the belt just about where the inner ribs stop and the solid section of the belt starts. So I guess it looses about 20% of the surface that will not touch the sheaf on shift out.
My take is that clutch will bring Doo to where all the other clutches are, once they figure out some quality control issues on it. By doing the fins and a new belt they pretty much admit to having issues, thats nice for 18 buyers just don't forget us along the way.

 

[Slick]

Rulonjj's needs no 18 improvements ! LOL.

 

[winter brew]

My money is on this being related to the amount of interference between the steel shaft and the sheave. Too tight combined with the thickness of the sheave and it "pop cans" at some point....from heat or simply the pressure exerted by the belt. That's my theory for what it's worth, which isn't much.
Material selection, tweaking the mating of the parts,, assembly process or a thicker sheave to fix???
Classic first year gremlins, hopefully Doo will make it right for everyone.

 

[rulonjj]

Rulonjj's needs no 18 improvements ! LOL.

Lol. You're absolutely right. Thanks for finally admitting it.



Jk
Every sled could use improvements. After towing 5 different cats out last year and screwing around with my pos axys this year, skidoo has treated me the best BY FAR.

There's no doubt skidoo needs to fix their clutches. They have been running hot clutches for a dozen years now and the pdrive hasn't proved to be an improvement in that area. But in rpm consistency and ease of service they have made improvements. The biggest thing that bothers me isn't the problems. That's always a risk with first year sleds. The thing that bothers me is how skidoo isn't admitting there is a problem. It's good to discuss these issues but unless people are calling and emailing skidoo they will never fix the issues. Kinda like when Polaris didn't fix their engine issues for 10+ years.

 

[fredw]

Sounds like many here will need, get the rpm more consistent and clickers doing what they were meant to do, any pictures of them compared to stock setup..

Buddy that put the older tra race primary on his G4 is loving life he says, will get out with him soon to see its consistentcy

Just got of the mountain after a weekend of testing.

4 sleds 4 different setups.

Hands down the ZRP weights win with the most consistent rpm from 2000 to 5000 feet this weekend pegged right at 8000 temperature from - 18 C to-3 C late afternoon.

The others had stock setups with weight and sea level setups with 951 arms less pin weight for elevation and mine has the SHR set up with the 968 weights. (it is the most finicky for elevation but the clickers are way more effective than on the stock setup -- go figure

If all sleds runs right on 8000 they have the most consistent performance and there is very little difference on an uphill pull in a foot and a bit of powder. The ZRP set up with the 85 GR weight and full load in the bottom and 2 grams in the middle just ran best and more consistent than any of the others.
Clickers are simply not needed on that setup.

One Guy granated a belt so bad it shattered the plastic on the guard and the rubber melted right into the remaining plastic. On my wife sled the steel bottom section in the clutch wears a groove on the fixed sheaf side of the belt just about where the inner ribs stop and the solid section of the belt starts. So I guess it looses about 20% of the surface that will not touch the sheaf on shift out.
My take is that clutch will bring Doo to where all the other clutches are, once they figure out some quality control issues on it. By doing the fins and a new belt they pretty much admit to having issues, thats nice for 18 buyers just don't forget us along the way.

 

[Ski-doo#1]

Just got of the mountain after a weekend of testing.

4 sleds 4 different setups.

Hands down the ZRP weights win with the most consistent rpm from 2000 to 5000 feet this weekend pegged right at 8000 temperature from - 18 C to-3 C late afternoon.

The others had stock setups with weight and sea level setups with 951 arms less pin weight for elevation and mine has the SHR set up with the 968 weights. (it is the most finicky for elevation but the clickers are way more effective than on the stock setup -- go figure

If all sleds runs right on 8000 they have the most consistent performance and there is very little difference on an uphill pull in a foot and a bit of powder. The ZRP set up with the 85 GR weight and full load in the bottom and 2 grams in the middle just ran best and more consistent than any of the others.
Clickers are simply not needed on that setup.

One Guy granated a belt so bad it shattered the plastic on the guard and the rubber melted right into the remaining plastic. On my wife sled the steel bottom section in the clutch wears a groove on the fixed sheaf side of the belt just about where the inner ribs stop and the solid section of the belt starts. So I guess it looses about 20% of the surface that will not touch the sheaf on shift out.
My take is that clutch will bring Doo to where all the other clutches are, once they figure out some quality control issues on it. By doing the fins and a new belt they pretty much admit to having issues, thats nice for 18 buyers just don't forget us along the way.

So what problem does the ZRP flyweights solve? Just lower RPM, which lowers heat? So now that guy isn't having issues? Or was he ever having belt issues?

The guy that grenaded the belt what was his setup?

So maybe a better flyweight setup fixes half the issues people are having, pulling hard, consistent Rs, and reduced temps.

If there exists a lot of crooked fixed sheaves and that is causing the other half, I would hope Ski-doo addresses it for 2017 riders, although I am not going to assume that is the issue for most guys. It seems they have re-calibrated the internal clutching for 2018 and added the fins of course. I think the '18s will be the best to date. IF IF IF crooked fixed sheaves are the other half of problems:

1.) I think this would've been felt much sooner than now
2.) Are we sure this particular sled or others hadn't blown a belt previously? Above the rated RPMs, causing more damaged/crookedness than designed for?
3.) IF it is an issue I really believe the only reason Ski-doo let anything slip is because they sold SO MANY of these BEASTS in their first year and potentially struggled to keep up.

I can say I have heard much more good things about them then I have heard bad. The only place I hear bad is on forums, where I also hear good, but mostly coming from Polaris trolls on snowest. I truly believe and have seen more people out there enjoying them vs. in here having issues.

 

[rulonjj]

Just got of the mountain after a weekend of testing.

4 sleds 4 different setups.

Hands down the ZRP weights win with the most consistent rpm from 2000 to 5000 feet this weekend pegged right at 8000 temperature from - 18 C to-3 C late afternoon.

The others had stock setups with weight and sea level setups with 951 arms less pin weight for elevation and mine has the SHR set up with the 968 weights. (it is the most finicky for elevation but the clickers are way more effective than on the stock setup -- go figure

If all sleds runs right on 8000 they have the most consistent performance and there is very little difference on an uphill pull in a foot and a bit of powder. The ZRP set up with the 85 GR weight and full load in the bottom and 2 grams in the middle just ran best and more consistent than any of the others.
Clickers are simply not needed on that setup.

One Guy granated a belt so bad it shattered the plastic on the guard and the rubber melted right into the remaining plastic. On my wife sled the steel bottom section in the clutch wears a groove on the fixed sheaf side of the belt just about where the inner ribs stop and the solid section of the belt starts. So I guess it looses about 20% of the surface that will not touch the sheaf on shift out.
My take is that clutch will bring Doo to where all the other clutches are, once they figure out some quality control issues on it. By doing the fins and a new belt they pretty much admit to having issues, thats nice for 18 buyers just don't forget us along the way.

Glad to hear the zrp weights are working out. I find it interesting that most of the people saying the rpm drifts around on the pdrive, are in low elevation. Everyone I talk to that rides 9000-12000 feet say they are super consistent. Maybe they have a hard time holding the belt when the sled is making more power. I'm of the opinion that the ramps are just way off. They need more tip weight and a better profile.

 

[Daag44]

Lol. You're absolutely right. Thanks for finally admitting it.



Jk
Every sled could use improvements. After towing 5 different cats out last year and screwing around with my pos axys this year, skidoo has treated me the best BY FAR.

There's no doubt skidoo needs to fix their clutches. They have been running hot clutches for a dozen years now and the pdrive hasn't proved to be an improvement in that area. But in rpm consistency and ease of service they have made improvements. The biggest thing that bothers me isn't the problems. That's always a risk with first year sleds. The thing that bothers me is how skidoo isn't admitting there is a problem. It's good to discuss these issues but unless people are calling and emailing skidoo they will never fix the issues. Kinda like when Polaris didn't fix their engine issues for 10+ years.

Other than the comments for the Polaris issues for 10+ years, I agree 100%.

 

[powdermuncher]

Glad to hear the zrp weights are working out. I find it interesting that most of the people saying the rpm drifts around on the pdrive, are in low elevation. Everyone I talk to that rides 9000-12000 feet say they are super consistent. Maybe they have a hard time holding the belt when the sled is making more power. I'm of the opinion that the ramps are just way off. They need more tip weight and a better profile.

Agreed the ramps are way of for the 850. The fact that they arrived with the heaviest pin weight in place without options to go up (to me) was the signs of a setup on the edge of design perimeter.
Typical first season teething issues.
None of the Doo weights have a shift curve that suites the 850 over the full shift. So far ZRP is the best we have tried, I will mess around with my second sled with them as well to see if I can find some gains over the set up I have right now.

 

[Ski-doo#1]

So I think it is limited down.

1.) Too many rpms, creating too much heat.
2.) Potentially some sheaves out of place, don't know from factory or if from previously blown belts.

Solutions

1.) Install necessary flyweights. Don't mess with clickers until you're close to 8,000

2.) Have you dealer take a peek unless you're qualified to test alignment

Sounds like most people are getting belts warrantied so although Doo might not be admitting to a problem they aren't screwing the customer out of belts. Maybe they haven't found the problem? Maybe they can't say what the problem is because it isn't consistent? Maybe they don't believe there is a problem that is affecting too many sleds?

 

[sledheadjake]

I just checked my primary stationary sheave, its .027 out of true. Not sure if this is the main issue , but its for sure not right. Contacted my dealer today and they are starting a claim with BRP. I have blown 2 belts in 400 miles, my dealer has so far changed the helix(with no change in clutch temps) and they lowered the gearing (again with no change).Now on my 3rd belt and pulled a string this weekend after 15 miles of trail riding

 

[rulonjj]

I just checked my primary stationary sheave, its .027 out of true. Not sure if this is the main issue , but its for sure not right. Contacted my dealer today and they are starting a claim with BRP. I have blown 2 belts in 400 miles, my dealer has so far changed the helix(with no change in clutch temps) and they lowered the gearing (again with no change).Now on my 3rd belt and pulled a string this weekend after 15 miles of trail riding

Being that far out of true would basically be the same as shifting in and out each revolution. That would create a lotta heat and belt dust.

 

[mountainhorse]

BACK TO BASICS

This first year release for the 850... as a complete new sled/engine/driveline combo....

Again, the video shows a clutch... if chucked up accurately in the lathe has way too much run-out.




The belt/clutch/engine alignment issues are not consistent in all of the consumer sleds.

There ARE a significant number of people that have clutching/belt issues.... and also a significant number that dont.... some people ride super hard and some dont.... some have a riding/throttle style that promotes longer belt life than the "pin-n-wiggle" method ...Suffice to say, some riders bring out belt wear more than others do.

BRP adding cooling fins is a big "tell" that they know they have thermal problems...and it is not the HP or torque of the motor that is causing unavoidable heat.

To me, the cooling fins are great to have, and add some mass to the clutch as well... but it's a bandaid.... The heat should not be there in the first place.... Plenty of belt driven turbo sleds of all brands that do not have belt heating issues, even with turbos and super aggressive riders on them.

SO... Back to basics...with questions. Looking at the forrest for the trees... the "Big Picture" .... viewing this as a SYSTEM of related components and design parameters.

What causes excess heat in a CVT clutching design??

Is the heat from calibration or another issue?

1) Is there a lack of dynamic alignment stability?.... How well does the belt maintain alignment while heavily loaded in constantly varying terrain. Motor mounts, bulkhead flex etc are contributors here.

2) Are there Clutch malfunctions? (rollers, bushings etc) or running out of true as shown in the video here.

3) Are thereClutch tuning/calibration issues?.... Are the clutches 'squeezing' the belt with enough pressure... is the belt riding in the clutch in the right position, is system backshifting/upshifting correctly, is the deflection remaining constant, is there variance in production C-2-C distances, does C-2-C change under load, does the secondary need to float, is the jackshaft flexing ...???

4) What can cause inconsistency in results of one consumer compared to the next??... some that have ZERO issues while others have serious issues that impede having confidence in the sled?

Are there manufacturing tolerances, durometer inconsistency issues in motor mounts, out of spec machining, tolerance-stacking issues from wide tolerance specs etc?


To focus on just one doesn't do much for you if the problem stems from another cause or combination of issues.



A side question I have for the die hard BRP people here.... is the line between centers on the primary and Secondary more vertical on the G4 than on the XP/XM? (is the secondary more on-top of the primary than the previous models?).



.

 

[Hawkster]

A side question I have for the die hard BRP people here.... is the line between centers on the primary and Secondary more vertical on the G4 than on the XP/XM? (is the secondary more on-top of the primary than the previous models?).

What I've noticed out in the field is the clown behind the throttle . Some people loose their head as soon as they fire the machine up .

A far as your question about the stacking of the clutches that is some pretty heavy stuff . There's a reason why nascar only does left turns and I think you just related the two .

That's a good one

 

[sledheadjake]

It would be awesome if someone that does not blow belts and the clutches are not running extremely hot, if they could run a dial indicator check on their clutch and share the results.

Like I said previously my primary fixed sheave is .027 out of true, and I have eaten 2 belts in 400 miles and the clutches are hot as hell.

 

[christopher]

What causes excess heat in a CVT clutching design??

Is the heat from calibration or another issue?

1) Is there a lack of dynamic alignment stability?....
How well does the belt maintain alignment while heavily loaded in constantly varying terrain. Motor mounts, bulkhead flex etc are contributors here.

2) Are there Clutch malfunctions?
(rollers, bushings etc) or running out of true as shown in the video here.

3) Are thereClutch tuning/calibration issues?....
Are the clutches 'squeezing' the belt with enough pressure... is the belt riding in the clutch in the right position, is system backshifting/upshifting correctly, is the deflection remaining constant, is there variance in production C-2-C distances, does C-2-C change under load, does the secondary need to float, is the jackshaft flexing ...???

4) What can cause inconsistency in results of one consumer compared to the next??...
some that have ZERO issues while others have serious issues that impede having confidence in the sled?

5) Are there manufacturing tolerances,
durometer inconsistency issues in motor mounts, out of spec machining, tolerance-stacking issues from wide tolerance specs etc?


To focus on just one doesn't do much for you if the problem stems from another cause or combination of issues.


A side question I have for the die hard BRP people here.... is the line between centers on the primary and Secondary more vertical on the G4 than on the XP/XM? (is the secondary more on-top of the primary than the previous models?).

.

EXCELLENT QUESTIONS ERIC!
Lets see if we can get some answers...

 

[d8grandpa]

EXCELLENT QUESTIONS ERIC!
Lets see if we can get some answers...

Maybe excellent questions, but not ones that should have to be asked on a 2017 sled!!!
And don't hold your breath thinking you will get any answers from BRP.
I have personally put a lot of miles on beside these sleds all winter, and when they are running correct they are a performance beast. But the engineering and build quality is by far the worst joke in the industrie.
Maybe the 18's will be better, i hope for you doo peeps you will get some resolution.