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2019 new vents and clutching

M
Feb 7, 2009
1,142
606
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37
Wabush, Labrador
Not to piss on your parade, but you guys sound like engineers comparing kw to heat a home to a snowmobile with "belt issues" ... Maybe you are indeed engineers, thats ok too. I just think you are over thinking this a little bit.. and I believe BRP is right there with you.
Not saying I have all the answers, because I don't. I just believe this is a simple machine that has worked for numerous years. Now all of a sudden it is taking several model years to fix the issue.. It really shouldn't be that difficult.
 
S
Mar 6, 2008
510
346
63
Northern Sweden
Not to piss on your parade, but you guys sound like engineers comparing kw to heat a home to a snowmobile with "belt issues" ... Maybe you are indeed engineers, thats ok too. I just think you are over thinking this a little bit.. and I believe BRP is right there with you.
Not saying I have all the answers, because I don't. I just believe this is a simple machine that has worked for numerous years. Now all of a sudden it is taking several model years to fix the issue.. It really shouldn't be that difficult.

I am :face-icon-small-hap

The major problem I think is that stuff aren't where they are supposed to be. Either they are put in the wrong place from the start or they move around under load.... or a combination of the two.

A fixed secondary should not be a major problem, besides being a pain in the behind when working on the sled, as long as the engine is kept where it is supposed to be under all conditions.
What I would like to see is a minimum of 4 motor mounts, all, if not easily, at least possible to adjust. The motor mounts should with no exception be designed to NEVER, EVER pull on any rubbet/elastomer part. Compressing rubber = OK, Stretching rubber = Fail!
And why not try to separate the front mounts from the rear mounts more? The further they are from each other the less force the mounts will have to take. Front mounts could for example be between cylinder head and pyramid etc.
 
D
May 24, 2012
277
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28
Of course there is a lot of heat being created, even by a good clutching system. It's the "the clutches are soaking up 70% of the engine power"-myth I'm tired of hearing =)

Even if the clutches only transforms 5-10% of the engine power into heat that is a lot of energy, more than adequate to cause a lot of problems.

What I don't understand is why the old art of making solid, dependable, adjustable and durable engine mounts was forgotten? The old "clamp the engine mount between two rubber disks and run a big bolt with a spacer through it all"-style mounts went out of fashion? I know, there are more parts in that type of mounting system but it has the great advantage that regardless which way the engine wants to move it has to compress rubber, i.e no rubber parts are ever stretched which is a good thing!!


"Of course there is a lot of heat being created, even by a good clutching system. It's the "the clutches are soaking up 70% of the engine power"-myth I'm tired of hearing =)"

I wasn't aware it was a common myth that the clutching was soaking anywhere near 70%. I think that was my fault in one of my previous replies.


"Even if the clutches only transforms 5-10% of the engine power into heat that is a lot of energy, more than adequate to cause a lot of problems."

It is a crazy amount of heat. When it gets too high the belt just blows up.


"What I don't understand is why the old art of making solid, dependable, adjustable and durable engine mounts was forgotten? The old "clamp the engine mount between two rubber disks and run a big bolt with a spacer through it all"-style mounts went out of fashion? I know, there are more parts in that type of mounting system but it has the great advantage that regardless which way the engine wants to move it has to compress rubber, i.e no rubber parts are ever stretched which is a good thing!!"

If you look carefully at both PTO engine mounts, they are exactly as you described wanting them. The one on the MAG side compresses the rubber which is also exactly as you would like it to be :face-icon-small-ton

By comparing each generation of the REV chassis, the G4 is by far the easiest of the bunch to adjust alignment. No more impossible to reach engine mounts and only common tools are needed. Even the pDrive provides a far easier way to take the alignment in ways that we never could before, and it's a lot easier.
 
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S
Mar 6, 2008
510
346
63
Northern Sweden
I wasn't aware it was a common myth that the clutching was soaking anywhere near 70%. I think that was my fault in one of my previous replies.

Perhaps you have better educated friends than me :face-icon-small-hap

But most often when drive train efficiency comes up people, and not just among my friends, talk about losses in the clutches and chain case and leave the track out of it completely implying that the major losses have nothing to do with the track.

So you say that no engine mounting rubber part is strained in this design, only compressed? That is good news!

In any case, I'm keeping all fingers and toes crossed that my sled will work just fine and that I won't regret switching to BRP. (had 2 E-tec 800 sleds before the RMK I have now and I do not want to get used to changing belts all the time again)
 

Big10inch

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Mar 11, 2018
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. It should be mentioned though that not many riders uses a power output above 140 hp continuously or even for more than a few seconds at a time.



Pretty sure mountain riders exceed that by a huge margin. We have days when there is 3 feet of fresh snow and an 8 mile road in. That means full power for 20-30 minutes or you are going nowhere. Just simple climbs up through the trees require a LOT more than just a few seconds of full power, or again, you are not making it. My Polaris sleds would go 4-500 miles on a belt, my Cat probably more like 5-600. Deep snow riding takes its toll on the power transmission.


I also do not think Doo has the most track resistance, I think the tight track on Polaris sleds is by far the hardest to turn by hand. Deflection on the Polaris is 3/8" to 3/4" with ten lbs on the track. I think my cat will easily run with 2-3 inches of deflection with the same weight, no idea what the Doo spec is but it is unlikely tighter than Polaris.
 
D
May 24, 2012
277
96
28
Perhaps you have better educated friends than me :face-icon-small-hap

But most often when drive train efficiency comes up people, and not just among my friends, talk about losses in the clutches and chain case and leave the track out of it completely implying that the major losses have nothing to do with the track.

So you say that no engine mounting rubber part is strained in this design, only compressed? That is good news!

In any case, I'm keeping all fingers and toes crossed that my sled will work just fine and that I won't regret switching to BRP. (had 2 E-tec 800 sleds before the RMK I have now and I do not want to get used to changing belts all the time again)


I think your 2019 will need some attention on the alignment if you want the belt to last. Of course I don't know how well the new venting will compensate in heat reduction. I'm waiting for the preloader from Grip-n-Rip to see what shims are needed for 3 2018 Freeride and 1 Summit. The owner on the 2018 BCX isn't hard on his belt to begin with. He is still on the first 531 belt after 4000+ km . The owner on the Summit is also easy on his belt and still on the first one. In those 5 sleds, those that are ridden the hardest have gone through more belts.

If you ride your sled hard then it makes sense to check the alignment before riding it. When a belt breaks out in the field it becomes tough to give the clutches a good cleaning before installing the spare. So the next belt tends to get a much shorter life.

Blowing a belt is the worst thing that can happen for a 2S crankshaft. I'm currently looking for a low mile 850, but I'm not interested a belt eater that went through 12 belts as it's an engine failure waiting to happen. Those 2 piece cranks are not cheap. I'll probably go for a left over 2018 or a 2019 late in the season. There is no way that I'm dealing with the nonsense of owning a 2S that ran 300+ F belt temps. My time on a sled is to be relaxed, not to worry about who's responsibility it is to keep the sled running well.
 
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summ8rmk

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Feb 16, 2008
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yakima, wa.
I usually don't get further than 15miles from the truck and seldom get over 50 miles in a day. Both the sled and myself are out of gas.

If i was 40miles from the truck that would equate to 120miles of riding for me,
I couldn't pack the extra 11gallons of gas to make it that far!
Agreed. I'm 30 40 miles from truck. Don't want to walk. Sled should be confident smiles all day

 
D
May 24, 2012
277
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Flat landers go through belts in 100-200 km on belt eaters. We have a lot more Hp to manage near sea level :face-icon-small-ton
 
S
Mar 6, 2008
510
346
63
Northern Sweden
I think your 2019 will need some attention on the alignment if you want the belt to last. Of course I don't know how well the new venting will compensate in heat reduction. I'm waiting for the preloader from Grip-n-Rip to see what shims are needed for 3 2018 Freeride and 1 Summit. The owner on the 2018 BCX isn't hard on his belt to begin with. He is still on the first 531 belt after 4000+ km . The owner on the Summit is also easy on his belt and still on the first one. In those 5 sleds, those that are ridden the hardest have gone through more belts.

If you ride your sled hard then it makes sense to check the alignment before riding it. When a belt breaks out in the field it becomes tough to give the clutches a good cleaning before installing the spare. So the next belt tends to get a much shorter life.

Blowing a belt is the worst thing that can happen for a 2S crankshaft. I'm currently looking for a low mile 850, but I'm not interested a belt eater that went through 12 belts as it's an engine failure waiting to happen. Those 2 piece cranks are not cheap. I'll probably go for a left over 2018 or a 2019 late in the season. There is no way that I'm dealing with the nonsense of owning a 2S that ran 300+ F belt temps. My time on a sled is to be relaxed, not to worry about who's responsibility it is to keep the sled running well.

I'm getting a Lynx, so i don't know if they are adding venting as Doo has. Looks clever though. (My GF ordered a -19 Summit 600 w the new 600R, wonder if the 600 is also getting the new venting?)

Any idea what the Grip'n Rip alignment/measuring tool will cost?


Who will judge if I ride hard? Probable answer is "some days I do, some days I don't" Am at sea level, almost, so full power is available. I do not think there is a sled/clutch/belt ever built that could survive "20-30min of full throttle" at our altitude. We ride mostly in the trees, both flatland and mountains so we are constantly on/off throttle bur rarely at wot for more than 10-30s, but even that is enough for many sleds to start heating the belt.
 
D
May 24, 2012
277
96
28
I'm getting a Lynx, so i don't know if they are adding venting as Doo has. Looks clever though. (My GF ordered a -19 Summit 600 w the new 600R, wonder if the 600 is also getting the new venting?)

Any idea what the Grip'n Rip alignment/measuring tool will cost?


Who will judge if I ride hard? Probable answer is "some days I do, some days I don't" Am at sea level, almost, so full power is available. I do not think there is a sled/clutch/belt ever built that could survive "20-30min of full throttle" at our altitude. We ride mostly in the trees, both flatland and mountains so we are constantly on/off throttle bur rarely at wot for more than 10-30s, but even that is enough for many sleds to start heating the belt.


I believe $250 USD. No need to worry about the load. You can set med to max load to be very close to alignment. Then the X offset is adjusted to keep the belt from having to bend in an S.
 

donbrown

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Nov 26, 2007
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The single largest, by a vaaaaaaaast margin, energy eater in the system is the track, not the clutch system.

I think the track makes the sled go … so transferring energy produced by the engine and ending up being used by the track is a good transfer of kinetic energy. :face-icon-small-hap
 
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