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G4 BELT EATER! [2017 Ski Doo 850 Rev G4 clutching/belt fix?] Belt Issues

J

jsenske

Member
Sep 7, 2012
41
8
8
UP Michigan
Pulled my first cord on a belt today. Right at 612 mi, and I had been flogging it in over the hood powder for an hour and 42 minutes pretty much non stop. Belly fight grenade, just pulled about an inch of cord, so now it will be a spare. No complaints at all any the belt life, I was abusing it hard today. Sure is a fun sled in the deep stuff though.

Wouldn't complain a bit with that belt life. A belt with a string out is not worth being a spare imo
 
P
Nov 28, 2007
1,795
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Yukon Canada
I'm not saying I don't believe some people are having issues. I know it is there but it isn't on every single model out there. So to be scared away from buying this machine makes no sense. It is a luck of the draw type of thing it seems, which sucks.

What I'm getting at is if people believe they are having problems because of too much rpm and then adjust their clickers to compensate are they potentially doing more damage as they don't realize clicker position doesn't affect RPM. Instead clicker position should be used as snow conditions vary. If you want to change engine speed change weight. Although, yes, RPM might slightly be affected by clicker change it isn't substantial.
By adjusting Clickers you move the eccentric effectively moving more weight ahead of the pin and adding weight -- if you go up to a higher number it does the opposite effective removing weight from ahead of the pin. So the Clicker is a way to add or reduce weight without much fuss. If you run out of adjustment on the clicker you need to add or subtract weight on the pin or go to a different weight shift arm all together. In the race manual it actually tells you how much weight each clicker adds.
 

sledhead_24_7

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Jul 30, 2008
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Jackson Wy
The belt issue is REAL.

If you have a machine that hasn't had a issue wether it is how you ride, where you ride, or just flat got a good one, GREAT
Those of us having issues do not care about your comments on " mine is perfect, so the rest of you must exaggerating " type comments.

I am convinced it is a combination of motor mounts and clutch component issues.
 
B

blk9038

Well-known member
Aug 8, 2011
573
259
63
74
puyallup/edgewood
Pulled my first cord on a belt today. Right at 612 mi, and I had been flogging it in over the hood powder for an hour and 42 minutes pretty much non stop. Belt didn't grenade, just pulled about an inch of cord, so now it will be a spare. No complaints at all with the belt life, I was abusing it hard today. Sure is a fun sled in the deep stuff though.

I had to tow my friends 13 pro 163 in all the way back up hill and down hills from half way over to ravens roost Saturday, was hoping to trash /check out if you had any ice over your way, his top end let go so I put the 850 on rpm and kept it about 5700 to 7000 for about 14 miles back to truck did rest at top of pyramid pass to cool off the 850 but only stopped for 5 mins had to go all the way down to lower gate at greenwater, pulled cover off clutch and belt still looked great but fairly hot to touch minimal belt dust and was glad it was a 165 track as some ice towing back too. lucky our other friend had backup sled Saturday as mine were in my trailer at home but friend is probably abandoning Polaris and getting a 850 soon, in the meantime he will get to put miles on my 12 xp 163. love the sled. so got to do Saturday with snowjammers/and exploring greens pass.
 

snowmanx

Well-known member
Premium Member
Aug 13, 2001
2,163
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83
54
Polson, Montana
I'm not saying I don't believe some people are having issues. I know it is there but it isn't on every single model out there. So to be scared away from buying this machine makes no sense. It is a luck of the draw type of thing it seems, which sucks.

What I'm getting at is if people believe they are having problems because of too much rpm and then adjust their clickers to compensate are they potentially doing more damage as they don't realize clicker position doesn't affect RPM. Instead clicker position should be used as snow conditions vary. If you want to change engine speed change weight. Although, yes, RPM might slightly be affected by clicker change it isn't substantial.

Don't be scared away.....it's a luck of the draw thing?

Well, for $14000, it's scared me away! I wanted one of these macgines so bad, but now I'll have to wait to see if they get it figured out.


Don't be scared away,
 

smokindave

Canada Moderator
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Nov 26, 2007
4,146
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Calgary Alberta
Yeah I too am scared to get a Doo.
Between killer pine cones and burning belts I think I'll be going to a tank yami,at least I know they R&D'd properly before releasing!;)


Sent from my iPhone using Tapatalk
 
B
Feb 18, 2009
233
150
43



BRP's 2018 media releases regarding improving 850 CVT heat issues (cooling fan, airflow mgmt across the CVT system etc) seem to be good additions to minimize the effect of the symptom of heat produced.

My questions for brpcare:

1)Has your engineering and production team determined the cause of the actual higher than normal CVT temperatures in the G4-850 Summit line for 2017?

2) Why do the G4-850's that are NOT problematic in terms of frequently blown belts, still have higher than normal CVT temps when compared to the ETEC 800's, and even high HP turbo versions of the ETEC 800's?


This question is related to 3 G4-850 sleds I have in my shop right now.

.

1- I would think it's safe to assume the improved calibrations and improved clutch guard (for cooling) are all directly related to improved clutching and reduced heat. Seems like a no brainer!

2- Isn't it obvious? Less then ideal calibrations (clutching and gearing). This is a brand new clutch on a snowmobile with a new engine and chassis... There was bound to be optimizations for the second year!
 

mountainhorse

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Dec 12, 2005
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www.laketahoeconcours.com
I can see your points and apreciate your input...

My 2 questions are for brpcare...(purpose of this thread)


1) Still leaves the question, clearly, of CAUSE.

2) Relates to the NON problematic sleds.... Across the board, the G4-850 has elevated CVT temps compared to other models of sleds of similar, or higher, output. (Enough to need to put a fan on the stationary sheave of the 2018 G4-850)


There are two ways to reduce heat
A) Prevent heat from being produced in first place (best method)
B) Remove heat after it has been produced (Non efficient method)






.
 
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NHRoadking

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Just seams like this is a temporary fix for another much bigger problem.. How many sleds out there making much bigger power than 160 and sot having cooing fins on primary.. Maybe find the reason for the heat and fix that:juggle:

Are you having problems with your 850 Summit with clutch heat?

Have you tried some of the suggestions to reduce heat? Any luck?

Sounds like Doo is looking at several different things to reduce heat (clutch calibration and motor mounts).
 
T
Oct 24, 2010
32
15
8
Bc
Stock Floating clutch please. Been running the skidoo floating clutch since 14 and experienced great belt life. put it on my 16 xm holdover and no blown belts. unfortunately after about 800 km this season the sheave spline came apart so i had to put in stock secondary. Blew a belt within 100km since dealer put stock one in, getting way hotter without the float.
 

1Mike900

Well-known member
Premium Member
Dec 5, 2007
996
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43
Bellevue, Wa
Maybe the fins are to help keep the PTO bearing and crank cooler only? Looking at the pic above, is the fixed sheave mounted .024 off ctr like the '17, or now straight? I for one have never liked a stroke beyond 3.00" in a small 2 stroke engine, nothing but problem child! Also, what is the rod/stroke ratio? Mike
 
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D
May 24, 2012
277
96
28
Daag44 I've been watching all the forums for a real fix for the hot clutch issue
And I dont believe I've come across the fix,
Just suggestions to deal with heat from the clutches.

I agree with fredw about the hot clutch issue being more about the rider and not the sled..
The guys blowing belts are blowing through a tank of fuel in 2 to 3 hours?
I burn 5-6 gal. In 6hours
And my clutches are way too hot to touch.
Still on my original belt @ 500 miles

I know this can seem an overly complex issue, but the easiest way is to first draw from the fundamentals of the Driveline which is everything after the engine and to the track. The next step is to scout for those who have managed to make it work well. The Driveline on sleds is a massive subject that I hope BRP can take some of their best minds to work a document. If a simple guy like me can do it, I am certain the brilliant minds @ BRP can. And I say this with conviction because the great majority of what I learned on clutching came from BRP in the 90s when I first began racing sleds in small venues. When I look at the iBackshift web site I recognize many concepts that were drawn from BRP's own engineers and Aaen Clutch Tuning Handbook. Most would be shocked at how much can be drawn and learned from BRP texts alone. But it is the person behind the web site that I respect immensely for making many of these concepts available to the public in a way that can be easily understood and applied to our sleds.

I have good reason to believe the fundamental problem with Blown Belts has been the communication. For this I do not hold BRP responsible simply because sifting through the forums is a nearly impossible task. The proof is that you have looked and did not find. So how many hours did I need to invest to build just a simple timeline. I am in between two seasonal jobs, so time is not an issue. After participating on forums for a number of years, it is also much easier for me to separate those who Cry Wolf from those who are genuinely trying to help. I can assure you that those who have been trying to help have been overshadowed by those who continue to claim the new technology does not work. And of course I can back-up my claim otherwise I would not have posted on a BRP Thread.

So if you want to show BRP what you can do to lower the Belt Temperature on your 850, this is your chance. I won't solve it on my own, but I can show you how to address the problem without waiting for a 2018 calibration. If you have snow left to ride, you really shouldn't wait. Hot Belts and Blown Belt simply should not be in the same sentence with High Powered Two Strokes.
 
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