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Discussion Starter · #1 ·
In the moguls going slow under 20mph isn't fun with the clutch engaging, disengaging. Jerky and Bit tiring
For sure. Any fix for it? Thanks
Can't find the jerky 850 thread....
 

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Radicalrex, it was good talking to you today. It was a pleasant surprise to hear someone who rides much the same way I do. The low speed on/off throttle jerkiness is something that bothered me on the 2018 Freeride 850 146" that I rode. I found it a contentious issue offline as much as online. I believe - without measuring - that there is a part of it that is in the ignition/fuel timing that we can't do much about, but the magic is in the clutching, gearing and deflection.

Here is one thread that addresses the issue. The deflection adjustment is one thing I do differently, but trial and error on the deflection is easy and tells the story.

"Snappy" throttle/clutch engagement.
Started By addano, Dec 15 2019 01:06 PM
 

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This one is on SnoWest and refers to lowering the engagement down to 2,700-2,800 rpm. I consider this to be a dramatic drop in engagement.

https://www.snowest.com/forum/showthread.php?t=443375

Had my 17 850 Summit down to 2500/2700 using a qrs secondary spring that just fit over the primary hub. Still didn't get rid of the off on carburation calibration; but definitely made it better. Maybe Joey's ramps with the new 100 lb start primary spring, one can smooth it out even more and lower it more. Also 120 and a 135 start springs too, but finish pressure are lower than the Dalton 100/370. I initially tried just shortening the production springs since there were no low force start springs in 17; but that didn't work well for me. Have to dig through my notes if I can find them to remember what Hotrod Sled shop H5 secondary spring that I used at the time. But with the lower newer primary start force spring, one should work.
 

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I think the primary spring on the 2018+ TNTs and Adrenalins engage at a lower engagement. And the 2018+ X and XRS kept the higher engagement spring (from what was standard in 2017)

My 2018 TNT is much more docile at engagement/low speeds than friends with 2017 850s.
 

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Had my 17 850 Summit down to 2500/2700 using a qrs secondary spring that just fit over the primary hub. Still didn't get rid of the off on carburation calibration; but definitely made it better. Maybe Joey's ramps with the new 100 lb start primary spring, one can smooth it out even more and lower it more. Also 120 and a 135 start springs too, but finish pressure are lower than the Dalton 100/370. I initially tried just shortening the production springs since there were no low force start springs in 17; but that didn't work well for me. Have to dig through my notes if I can find them to remember what Hotrod Sled shop H5 secondary spring that I used at the time. But with the lower newer primary start force spring, one should work.
I found the thread were some of you were talking about the jerkiness just recently. jcjc is another who didn't like the jerkiness and seems to enjoy the clutch kit. His is a mountain sled, so I don't know how well the kit applies to a trail sled. I haven't lowered the engagement as low as you have, but all this talk has me want to try it. Is it around 10 lbs per 100 rpm?

Clutch Tuning
Started By 2020tnt, Jun 29 2020 12:14 PM
 

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Daag44 thanks for firing back up my thread and posting possibilities to review, and start hopefully In the best direction the first time.
I don't foresee throwing in the towel on my 850x until exhausting some different ideas that it appears you have provided and influenced.
 

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My 19 600R does the same thing, very jerky.
That's what I suspected. There are none around me, but I couldn't see how the 600R had raised the bar so high for a 600cc and even compete with the 850 for short distances, that it would be silky smooth. I figure it is somewhere in between the previous 600HOE and the 600RS with the manufacturing race tune.
 

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Daag44 thanks for firing back up my thread and posting possibilities to review, and start hopefully In the best direction the first time.
I don't foresee throwing in the towel on my 850x until exhausting some different ideas that it appears you have provided and influenced.
I think it was bold of BRP to give us two high powered sleds that fit the high strung throttle happy sled owners. During our conversation I realized that BRP have distanced the 2S from the 4S further to draw even more on their strengths. I want a 2S to be light, nimble and steroid induced power monster. In this context I could not be happier that we are talking about calming down a wild horse.

I am a proponent to the aftermarket, which ironically I got from BRP's response to my aftermarket question on SnoWest. I honestly didn't quite get the importance of the aftermarket until then. Just recently Dynamo^Joe spoke about the 1.8 Billion dollar industry which I had no clue was that big. That is the main reason I never put down the OEMs or the Aftermarket unless I make a mistake. In this respect I believe this is another perfect opportunity for the aftermarket to tailor the CVT for different riding styles and needs.

Detuning only appears to be counter intuitive until I look at the off-trail technical segment that require more control of the power to the track. You case was interesting and I think will help shed light for other trail riders who are uncomfortable to admit on a public forum that they could use a little smoother on-off throttle without giving up the brute force acceleration when its wanted.

I hope to see you swing by Northern NY this next season to ride the spare Mach Z and see how smooth BRP made it with stock clutching.
 

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Get an expedition extreme next time.
And you can guarantee that every expedition extreme is smooth as glass - everyone built? How are they for getting out of a tree well in the mountains.. when you stick it in the soft snow???

Calibration - fuel and clutching is never perfect..there are always two tail ends to the bell curve... performance wise with fuel, air and clutch calibration, just like there is for belt alignment when you make it essentially non adjustable and rely on build tolerances. Some one gets these sleds that are built on the end of tolerances and they don't function like the normal sled.

I question if your suggestion is an answer to the guys current problem. I suspect he wants to fix what he has now. And not live with it until he buys his next sled.

But it's possible he might entertain your suggestion. Too nose heavy to my way of thinking for my type of riding.. but we all like something different.
 
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