Three 850s go out together ...

SidewaysInto3rd

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Chase each other through the woods. Deep spring snow. Throw in a couple of climbs.

They all pull over and put a laser temp gun on their belts.

Snowmobile A has full custom clutching. Helix, springs, ramps and super low gearing and a blowhole.

Snowmobile B has some clutching and vents and low gearing.

Snowmobile C has no clutching, lots of vents and stock gearing.

All three belts read 240 lol

What does that tell you other than 3 cooked belts ?

Nothing!

Carry on


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maxwell

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Chase each other through the woods. Deep spring snow. Throw in a couple of climbs.

They all pull over and put a laser temp gun on their belts.

Snowmobile A has full custom clutching. Helix, springs, ramps and super low gearing and a blowhole.

Snowmobile B has some clutching and vents and low gearing.

Snowmobile C has no clutching, lots of vents and stock gearing.

All three belts read 240 lol

What does that tell you other than 3 cooked belts ?

Nothing!

Carry on


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im glad you did that and im not even suprised at the results. go do the same to 3 XMS and likely same results. all of my XMs has extremely hot clutches and belts but never blew any. anyone blowing belts on a G4 it is not calibration related and this just confirms that
 

RGM

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Chase each other through the woods. Deep spring snow. Throw in a couple of climbs.

They all pull over and put a laser temp gun on their belts.

Snowmobile A has full custom clutching. Helix, springs, ramps and super low gearing and a blowhole.

Snowmobile B has some clutching and vents and low gearing.

Snowmobile C has no clutching, lots of vents and stock gearing.

All three belts read 240 lol

What does that tell you other than 3 cooked belts ?

Nothing!

Carry on


Sent from my iPhone using Tapatalk

There are no bandaid fixes. The slipping wobble clutch just generates too much heat. Only real fix is a new primary with a normal sheaves
 

maxwell

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There are no bandaid fixes. The slipping wobble clutch just generates too much heat. Only real fix is a new primary with a normal sheaves


laser an XM clutch i bet its the same temp. I agree with you the wobble clutch isnt a good idea but i dont think heat is the culprit here
 

fredw

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We did a few comparisons as well from xm, t3 , G4 .. With G4 always being the hottest, I would think pdrive design maybe not as efficient as were were led to beleve..

take a G4 and race xm or t3 on a flat trail where traction is solid for both.. Would think the G4 would have a decent gain with more hp and lighter track, but it's just the opposite when we did it.. Why is that!!
 

maxwell

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We did a few comparisons as well from xm, t3 , G4 .. With G4 always being the hottest, I would think pdrive design maybe not as efficient as were were led to beleve..

take a G4 and race xm or t3 on a flat trail where traction is solid for both.. Would think the G4 would have a decent gain with more hp and lighter track, but it's just the opposite when we did it.. Why is that!!


be more specific lol. "g4 being the hottest"

like by 1 degree? 2 degrees? 100 degrees?


these things are important
 

fredw

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G4s were 50f hotter same lines as xm or t3

talking with them same guys today, they picked up there sleds at dealer today, found one sled to have hit over rev few times, found tack to gauge to be off enough that it needed replacement, dealer also put in lighter primary spring, second sled now 4 belts in less than 800km, received new primary internals and bakers motor mount retrofit.. And new doo belt

no mention of wobble clutch or reason for belts blowing.. Just try this and doo will have them figured out for 18 if you want to snowcheck, but we don't want your used g4s, guys not to impressed, What a joke
 
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Big A

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laser an XM clutch i bet its the same temp. I agree with you the wobble clutch isnt a good idea but i dont think heat is the culprit here

Sorry if I'm outa the loop here but I'm a little confused, what are you saying the problem is Maxwell if it's not the setup or the wobble?


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maxwell

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Sorry if I'm outa the loop here but I'm a little confused, what are you saying the problem is Maxwell if it's not the setup or the wobble?


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i think its the alignment. ive been around ALOT of snowmobiles and any one that was a belt blower was an alignment issue. always. which explains why some are belt blowers and some arent its very hard to set that alignment perfectly and with the increased power and torque of that motor its just that much more critical. judging by the new engine mounts for 2018 im guessing skidoo is seeing that these machines are not staying within their specified alignment and torque specifications under load
 

Couch

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Ok. So doo can't get things lined up???? On three pro 8s & 3 pro 6s have only blown one belt in 11000k combined, and only 1 belt on 3 phazer mtns with over 19000 km.
Looks like the wobbly bits idea may have come from too many wobbly pops. Hope it gets resolved soon!

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007sevens

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i think its the alignment. ive been around ALOT of snowmobiles and any one that was a belt blower was an alignment issue. always. which explains why some are belt blowers and some arent its very hard to set that alignment perfectly and with the increased power and torque of that motor its just that much more critical. judging by the new engine mounts for 2018 im guessing skidoo is seeing that these machines are not staying within their specified alignment and torque specifications under load

Bad clutch design, poor engine mounts , bad alignment....All lead to heat and heat will take belts out PERIOD. If your seeing that your sleds or the sleds you ride with are not taking belts out its because you dont ride them long enough or hard enough to over heat the belt. Hold your sled to the pin for 30kms and see if your belt blows. Trust me I have been around ALOT of sleds.
 

roadlinur113

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Bad clutch design, poor engine mounts , bad alignment....All lead to heat and heat will take belts out PERIOD. If your seeing that your sleds or the sleds you ride with are not taking belts out its because you dont ride them long enough or hard enough to over heat the belt. Hold your sled to the pin for 30kms and see if your belt blows. Trust me I have been around ALOT of sleds.

30 km to the pin?....thats one big hill.....or a terrifying ride up the trail to get there lol
 

ktmsx350f

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When you checked temps what was the difference primary vs seccondary on each sled ? Just add something i just did a blow hole on my axys and lowered temps by over 50 degrees.
 

RGM

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i think its the alignment. ive been around ALOT of snowmobiles and any one that was a belt blower was an alignment issue. always. which explains why some are belt blowers and some arent its very hard to set that alignment perfectly and with the increased power and torque of that motor its just that much more critical. judging by the new engine mounts for 2018 im guessing skidoo is seeing that these machines are not staying within their specified alignment and torque specifications under load

How can you properly align something with a wobble. If your tire rim was bent do you think that an steering alignment would fix it?
 

007sevens

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30 km to the pin?....thats one big hill.....or a terrifying ride up the trail to get there lol

Its not hard to ride it hard enough to get temps up. Remember Arctic cat in 12. They had a misalignment and The one we had in the group took belts out every time on the trail. average speed 55mph. Maybe to the pin is an exaggeration.
 

snochuk

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How can you properly align something with a wobble. If your tire rim was bent do you think that an steering alignment would fix it?

If you have the primary wobble and the secondary runs true your belt has to realign to the secondary. Pretty short distance to remove the oscillation that will be in the belt.
Not sure how you tune/calibrate/align that belt side loading out of the system. Maybe there is a way but that is for the designing engineers.
Side load oscillation would explain higher temps and exploding belts with no warning as belts not designed for side loads.

The only way to remove the oscillation would be to have all sheaves run true.
You can tune for best case average as is, but never remove the underlying cause.

This is a BRP thing to solve unless you want to mess with warranties and start machining parts $.

Not sure who will solve this first, private or BRP but hopefully some one does. Maybe it will be good primary for trails and hills once fixed?
Then loose the bandaid patch and put 3-5# more aluminum in the bulkheads and you would actually have a wicked stocker!
 
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RGM

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The big thing for all 850 owners is the heat comes from HP and that the HP that is going into heating the belt is not going to the track. Everyone would have 3-5 maybe more free HP if BRP fixes this wobble clutch
 

Daag44

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Broken Record

The big thing for all 850 owners is the heat comes from HP and that the HP that is going into heating the belt is not going to the track. Everyone would have 3-5 maybe more free HP if BRP fixes this wobble clutch


Sounds like a broken record, or worse the guy on the street shouting the end of the world is near.
 

NoBrakes!

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Re: Broken Record

Shouldn't a team floating secondary be able to take some misalignment out constantly?
 
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