Clutch sheave

kanedog

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Something is crooked. Hint-its not the $100,000 lathe.
 

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maxwell

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seen that on facebook. could blowing a belt cause it to go out of true? also I would like to see a Polaris and cat sheave on there.....maybe an XM sheave too.....perhaps all snowmobile parts are built that poorly and that actually isn't whats causing the belt issues. but sure looks like it could be the reason for sure
 

olymon

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Curious to hear what the face run out is when it's bolted on a motor and a dual indicator is put on it. Pull plugs and turn it over. Did you make a fixture to hold the taper?

Riding old sleds
 

RGM

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Curious to hear what the face run out is when it's bolted on a motor and a dual indicator is put on it. Pull plugs and turn it over. Did you make a fixture to hold the taper?

Riding old sleds

I need to do some maintenance on my sled tomorrow so will check that. I would think that something has happened to that clutch as the motor would jump around pretty bad if they were like that.
 

d mills

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I have very limited km on mine. But thought I felt a vibration last weekend. Now I'm curious.


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kanedog

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That particular sheave is 26 thou out.
Arbor was made that day, on the lathe and it was left in the lathe and was was not removed in order to keep it perfectly true. Both sheaves were done. Shaft was checked with dial indicator-perfect. Fixed sheave face checked-26thou out. You dont have to believe it. Redline found the same thing. Moveable sheave was true.
 
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snopro

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They are talking about this a lot on an 850 owners forum I'm on. There is something to this. Whether it is "the" problem for belts blowing up remains to be seen?
 

jhurkot

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I think there are 3 or 4 minor problems that add together and this could definitely be one of them.
1. poor factory calibration (clutch kit)
2. not enough air flow under the hood when bumper grill packed with snow (blowhole/vents)
3. motor mounts allowing the engine to flex/clutches not aligned (align with tool, add washer to the bad mount)
4. fixed primary sheave (can be machined straight)

Link to video...

https://www.facebook.com/david.sushynski/videos/10154244823417056/
 
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LBZ

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seen that on facebook. could blowing a belt cause it to go out of true? also I would like to see a Polaris and cat sheave on there.....maybe an XM sheave too.....perhaps all snowmobile parts are built that poorly and that actually isn't whats causing the belt issues. but sure looks like it could be the reason for sure
I too would like to see other manufacturers sheaves on there just for curiosity sake. Maybe that's normal or average across the board? Or maybe there are only a few out there that are like this?

All I know is it kinda reminds me of the first batch of 800r engines.......
 

Cableguy

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I have seen faces get warped like from a belt grenadeing would be interesting to see one that is brand new on there with 0 kms
 

geo

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If this G4 850 issue becomes a "real" G4 850 issue then all G4 850 owners should become happy G4 850 owners because BuRP will send a G4 850 "important message" to all G4 850 owners to visit your G4 850 dealer to have your G4 850 primary clutch inspected for a "possible" G4 850 clutch issue due to findings on a FEW G4 850's (maybe only 60 again) that have been found to have some G4 850 belt issues due to the G4 850 owners abuse "possibly" leading to a non-abusive G4 850 owner having a less than ideal G4 850 ownership experience.

The reason BuRP will address this "possible" G4 850 issue, IMO, at the owner level instead of just the future model level like so far with the couple of "possible" G4 850 issues, is because other "possible" G4 850 issues, although blown completely out of proportion by every site on the net this season, don't really effect the makers of the G4 850 as much as this "possible" G4 850 issue simply because of the cost of a G4 850 engine and the labour cost of the G4 850 dealer.
A "possible" G4 850 issue like this "possible" G4 850 issue, if neglected or poo pooed as internet gossip only, like all to present "possible" G4 850 issues, that even though are not real G4 850 issues but just "possible" G4 850 issues and actually have been attempted at being addressed, for some reason only BuRP knows, in the new G4 850 model,,, is a MUCH different "possible" G4 850 issue.

Even the "mighty" G4 850 motor will not live long if the "possible" G4 850 issue pictured in this thread is even slightly a "possible" G4 850 issue because the designers of the "mighty" G4 850 engine never would have predicted or tested having such a "possible" G4 850 issue of major belt load changes 8000 times a minute.
Has there been any "possible" G4 850 issues of PTO side failure? Any answer as to why from the tech or BuRP.

Unless you feel lucky, or don't care if you may wait for parts mid season next year, warranty or not, IMO get a dial indicator on your sheave. Then park it NOW or pay later if you find such a huge run out. It's not good for your motor. Really.
And no, it's not normal or seen before since pressed on steel sheaves (this far out over the complete sheave) unless physically impacted by something like a hammer or the secondary flying off because your jackshaft snapped.
Even the cheap chinese clutches from the '12 to '14 Cats never measured this bad and Cat gave away plenty of clutches back then.
 

Teth-Air

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If this G4 850 issue becomes a "real" G4 850 issue then all G4 850 owners should become happy G4 850 owners because BuRP will send a G4 850 "important message" to all G4 850 owners to visit your G4 850 dealer to have your G4 850 primary clutch inspected for a "possible" G4 850 clutch issue due to findings on a FEW G4 850's (maybe only 60 again) that have been found to have some G4 850 belt issues due to the G4 850 owners abuse "possibly" leading to a non-abusive G4 850 owner having a less than ideal G4 850 ownership experience.

The reason BuRP will address this "possible" G4 850 issue, IMO, at the owner level instead of just the future model level like so far with the couple of "possible" G4 850 issues, is because other "possible" G4 850 issues, although blown completely out of proportion by every site on the net this season, don't really effect the makers of the G4 850 as much as this "possible" G4 850 issue simply because of the cost of a G4 850 engine and the labour cost of the G4 850 dealer.
A "possible" G4 850 issue like this "possible" G4 850 issue, if neglected or poo pooed as internet gossip only, like all to present "possible" G4 850 issues, that even though are not real G4 850 issues but just "possible" G4 850 issues and actually have been attempted at being addressed, for some reason only BuRP knows, in the new G4 850 model,,, is a MUCH different "possible" G4 850 issue.

Even the "mighty" G4 850 motor will not live long if the "possible" G4 850 issue pictured in this thread is even slightly a "possible" G4 850 issue because the designers of the "mighty" G4 850 engine never would have predicted or tested having such a "possible" G4 850 issue of major belt load changes 8000 times a minute.
Has there been any "possible" G4 850 issues of PTO side failure? Any answer as to why from the tech or BuRP.

Unless you feel lucky, or don't care if you may wait for parts mid season next year, warranty or not, IMO get a dial indicator on your sheave. Then park it NOW or pay later if you find such a huge run out. It's not good for your motor. Really.
And no, it's not normal or seen before since pressed on steel sheaves (this far out over the complete sheave) unless physically impacted by something like a hammer or the secondary flying off because your jackshaft snapped.
Even the cheap chinese clutches from the '12 to '14 Cats never measured this bad and Cat gave away plenty of clutches back then.

Do you think it's possible?
 
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