Blown Belt

[Jafo1970]

Something must be binding. At a half mile you should be pretty much maxed out in the 120s. I was running 118 on gps on snow in about 1000' being boosted.

 

[stone88]

Ok Jeff here's what you have to do.
Switch to the 8DN and shim the secondary so the belt has the proper deflection.

Also check the torsion in your secondary. I've had success so far with stock 3-3 configuration but I've seen some secondary come with looser settings. That could be your problem (swallowing belt). Try increasing torsion to prevent belt from dropping too fast in secondary.

Clean your clutches with acetone to removing potential oil contaminate and clean rubber off.

Make sure no snow gets to your clutches (ie broken belly pan and running in deep powder)

What gearing do you have? Too short of a gear (btx and mountain) means you can max then out quick with a tuned sled. Running with gears maxed out is hard on belts.

There are more advanced things to check if the above dont work but I bet you will find the problem.

There is also a possibility you damaged the bushing in the primary cover when you reinstalled it which can cause weird shifting behavior. I would inspect that.

I

I would be careful tightening the stock spring past that I was running 6/1 and was fine but it is binding on top end it wont GPS past 121 on GPS the speedo keeps climbing but speed stops seen 127-128 but gps said 121 and 124 on speedo said 120 so its out 4 mph consistently my viper is dead on with GPS
Now that I have the cat rollers on it actually works like it should and upshifts to fast with asll the extra power, this will require a different and stiffer spring as I have snapped belt in half on a low speed rollon. I guess its work in progress.Also the sled needs more gear for better mid and top end pull.

 

[Turbo Dynamics]

View attachment 124724 I

I would be careful tightening the stock spring past that I was running 6/1 and was fine but it is binding on top end it wont GPS past 121 on GPS the speedo keeps climbing but speed stops seen 127-128 but gps said 121 and 124 on speedo said 120 so its out 4 mph consistently my viper is dead on with GPS
Now that I have the cat rollers on it actually works like it should and upshifts to fast with asll the extra power, this will require a different and stiffer spring as I have snapped belt in half on a low speed rollon. I guess its work in progress.Also the sled needs more gear for better mid and top end pull.

If speedo says 126 to 128 and gps 121 it id simply because you are spinning, not because of clutch binding.

 

[stone88]

If speedo says 126 to 128 and gps 121 it id simply because you are spinning, not because of clutch binding.

No Im not spinning it was a fresh plowed ice road and speedo is out 4 mph consistently on ice and 5-6 on loose snow I have over 700 miles on and have tested quite a bit but now that the rollers actually work its not like a button anymore.

 

[Turbo Dynamics]

No Im not spinning it was a fresh plowed ice road and speedo is out 4 mph consistently on ice and 5-6 on loose snow I have over 700 miles on and have tested quite a bit but now that the rollers actually work its not like a button anymore.

So you say you are 100% hooking on ice with your trail track?

I will be testing on ice soon with my speed track with ice picks or chisels then i can confirm your finding.

 

[stone88]

So you say you are 100% hooking on ice with your trail track?

I will be testing on ice soon with my speed track with ice picks or chisels then i can confirm your finding.

Yes

 

[Beerman]

Seems like the 8jp is a good belt for short burst of acceleration. Or at least a break in between blasts like our testing.

8dn is more tolerant to heat and abuse.

When you guys install your adjustable weights make sure you are carefully pulling the primary cover. It is very easy to damage the bushing.

When you say 112mph was that speedo or gps?

112 on GPS. I must not be getting a full shift out. Here's what the secondary looked like before I cleaned it. Primary marks are a good 1/4"+ from the top.

 

[Turbo Dynamics]

You are clearly burning the belt in the secondary. Do you have any oil contamination?

No wonder your top speed is not good...

The 8dn belt should help with the slipping.

 

[jpr-ltx-dx 2015]

i am now testing a stiffer driven spring and dalton weights and tings are getting better and better as I can run trails and a lot of low speed roll on and hard accelerations and long pulls.Driven now stay a lot cooler.

 

[**sj**]

Stone is right... It was acting like a button.. Now as a true roller it's going to need more secondary spring.... And I'd try more helix as well

 

[Fleecer]

Yesterday tooling along rr bed 90-100 mph and went to give her more and kaapoooow....blew belt 520 miles. Thought perhaps self inflicted due to tune/muffler and Dalton weights, but my buddy also blew a belt couple hours later............all stock winder 334 miles. I hope we are a minority!!!!!

I had just completed first service at 501 miles and had cleaned and inspected clutches and everything looked great.

When I had installed Dalton weights at 60 miles, I collapsed clutch instead of removing cover, so I know there is no bushing damage.

I inspected all the rollers again and they looked fine with the naked eye, however after turning each one in my digital calipers, I found one that had an ever so slight flat spot.

I ordered a set of torlon rollers and installed an 8dn belt......hopefully my luck changes, but wont have time to ride until next week when my rollers arrive. I adjusted the belt deflection to run the 8dn the same way I would on the cat procross. (Adding/subtracting washers behind the center bolt.) I ended up removing the stock .40 shim/washer and replaced it with an .80 shim/washer and seems to be right....however have not field tested. I think this method is better than removing clutch and adding shims behind the 8mm bolts as many have stated, but I'm open to any comments.

I remember when I bought my 1100 turbo procross, I had done all the updates and belt my first belt at 1472 miles. After having dozens of yamahas and getting 6-7000 miles out of a belt I was quite disgusted. Fast forward to this winder.....I must say getting 520 miles out of a belt and seeing the ruined foam in my bellypan......I was less than thrilled. So....I'll be making a couple changes and keep moving forward.

That being said, I believe every problem has a solution....it's a matter and finding it.....hence the benefits of this forum.

 

[**sj**]

ive now heard of a few sleds with the daltons and blown belts... could be because they all have tunes...and flat spots seem to keep the clutch from shifting out so a flat spot could be the major culprit..

And has anyone heard of a 17' blowing a 8dn yet?

 

[Snowaddict]

For all of you guys blowing belts, what was your break in procedure? How many miles did you put on before you went wide open throttle?

 

[Turbo Dynamics]

ive now heard of a few sleds with the daltons and blown belts... could be because they all have tunes...and flat spots seem to keep the clutch from shifting out so a flat spot could be the major culprit..

And has anyone heard of a 17' blowing a 8dn yet?

The daltons are not to blame imo. We have sold a very large number of kits. Some stock sleds blow belts as well. If anything, Dalton weights seem to help by reducing belt slip during acceleration. However the guys running the Daltons for the most part make 40 to 60 more hp than stock and hit top speed end of the gears much easier. The secondary has trouble gripping the belt at top speed deep in the sheaves.

The customer who ran 132mph gps has extra gear and has yet to blow a belt. He has had amazing durability because that guy run his sled very hard. Other customers have ran 1000 miles Boosted on ecotrail. Powertrail customers seem to have a little less luck and 600 miles is what most will reach with a stock belt.

Flat rollers seem to be a strong factor. Break-in seems to be important on this soft factory drive belt. 8dn belt has better results.

I believe the issue lies in the secondary clutch and we will test until we find a definitive solution. We have to improve belt grip in overdrive.

At least the belts are very cheap, especially the 8dn and results are pretty good with it so far.

 

[Dieselxtx]

1070 miles on my BTX LE with 50/50 on and off trail ridden hard from day one wide open pulls sled is bone stock except for osp adjuster on the stock belt ran 40 miles of trails hard and a 101mph pull and my clutches were warm but not hot by any means just thought I would post good luck with stock sled and stock belt!