Belt problem critique please

[74Nitro]

You may end up needing less helix angle with more primary weight.
Can you post a pic of your helix ramp surfaces and secondary rollers?

 

[fatchance]

You may end up needing less helix angle with more primary weight.
Can you post a pic of your helix ramp surfaces and secondary rollers?

Sounds like it's a stock helix. Only change was the purple EPI spring which if you ask me isn't a good match for the full stock components. Not even sure if we were given the year of the sled to this point. It's extremely difficult to give advice for clutching when someone doesn't understand what they need to convey to get help. If you ask me from the way the belt looked. It got so hot it delaminated on the top of the belt and broke.

 

[WinderFab]

Sounds like it's a stock helix. Only change was the purple EPI spring which if you ask me isn't a good match for the full stock components. Not even sure if we were given the year of the sled to this point. It's extremely difficult to give advice for clutching when someone doesn't understand what they need to convey to get help. If you ask me from the way the belt looked. It got so hot it delaminated on the top of the belt and broke.

I think he has a 2020 btx.

 

[fatchance]

I think he has a 2020 btx.

I mean, like I said before the purple EPI spring is pretty stout and without added weight in the primary it's most likely slipping in the primary with too much belt tension and it can't deliver it to the track.
Wondering too if he is hitting his RPM which would help determine what needs to be done.

 

[74Nitro]

I mean, like I said before the purple EPI spring is pretty stout and without added weight in the primary it's most likely slipping in the primary with too much belt tension and it can't deliver it to the track.
Wondering too if he is hitting his RPM which would help determine what needs to be done.

See post #23 in this thread.

 

[Yamarus]

You may end up needing less helix angle with more primary weight.
Can you post a pic of your helix ramp surfaces and secondary rollers?

Mileage 3861 km. Everything is from the factory, nothing has changed. Wear is practically not felt.

Not even sure if we were given the year of the sled to this point.

Yamaha Sidewinder B-TX LE 153. Year of production 2019.

Sounds like it's a stock helix.

Stock helix.

Wondering too if he is hitting his RPM which would help determine what needs to be done.

This weekend I drove about 100 km. on soft snow. The clutch was hot. I didn't give full throttle.

 

[74Nitro]

Hard to tell in picture, but it appears in that first pic that the roller is wearing into the helix. The stock rollers are garbage in my opinion. It doesn't take much wear to affect the shift.

 

[fatchance]

Most likely just belt dust on the ramps, but my God 9750 rpm? That's WAY too high! Yank the 8JP out of there and put an Ultimax XS825 in there to bring the RPM back down to earth. RPM would still be on the high side above 9300 so you need to get some more weight in the primary to get RPM in check.

 

[fatchance]

Did you reset the max RPM recall after you blew the last belt? Thinking you bounced off the limiter when the belt let go. Earlier post says 9100-9300 which is still a bit too high. Timkin Ultimax XS825 will be an improvement.

 

[KnappAttack]

Did you reset the max RPM recall after you blew the last belt? Thinking you bounced off the limiter when the belt let go. Earlier post says 9100-9300 which is still a bit too high. Timkin Ultimax XS825 will be an improvement.

That max recall is absolutely worthless for any info, it reads so much higher than the sleds actually runs at. Its typically hundreds of RPM higher than the machine is really clutched for.

Any little spin or slip and it reads that that high. It's a worthless feature, unless you have zero track slip or belt slip, which is an absolute impossibility. Not even worth looking at the max recall.

 

[Bigblue1]

Mileage 3861 km. Everything is from the factory, nothing has changed. Wear is practically not felt.
Sidewinder B-TX LE 153. Year of production 2019.

This weekend I drove about 100 km. on soft snow. The clutch was hot. I didn't give full throttle.

I have a 2017. Blowing belts like crazy when I first got it. I had to take off 3 mm on secondary. Run at 58MM, with Thunder Products rollers and springs. Also check your primary rollers. mine where bad. I run the belt even or just below the top of secondary sheave. Since 1,500miles , I have not blown a belt with a 285 tune. I now have 9,800 hard ridden miles. Its a little annoying but once you get it down it is bullet proof.

 

[Simplespeed]

I have a 2017. Blowing belts like crazy when I first got it. I had to take off 3 mm on secondary. Run at 58MM, with Thunder Products rollers and springs. Also check your primary rollers. mine where bad. I run the belt even or just below the top of secondary sheave. Since 1,500miles , I have not blown a belt with a 285 tune. I now have 9,800 hard ridden miles. Its a little annoying but once you get it down it is bullet proof.

Your right on the mark at 58 mm. With a big tune big gains can be made without a very low wild first gear( high belt on secondary) or a max overdrive ( high belt on primary) as these conditions attribute to belt issues in some cases.. Whats more important is having the right shift both ways at the right time which delivers the power to the ground all the while keeping heat in check.. This will also slow down the unwanted belt dust which in turn extends the life and consistency in the function of both clutches….

 

[Yamarus]

Yank the 8JP out of there and put an Ultimax XS825 in there to bring the RPM back down to earth.

The last trip was with the XS825. When starting, I do not hear the sound of the belt. There are no belt marks on the clutch. But I'm still afraid to go full throttle. The clutch is still hot after driving in deep snow.

Did you reset the max RPM recall after you blew the last belt?

Unfortunately, I don't know how to do this. Sometimes I hear the engine hitting the cut-off point.

Also check your primary rollers. mine where bad. I run the belt even or just below the top of secondary sheave.

Before the last trip, I replaced one roller on the primary clutch with the original one. The rest is fine. The belt is also located slightly below the top edge of the clutch.



Maybe I should try setting the stock spring to 3-3 or 6-2? Maybe this will help at least a little. Or change the EPI tension to 0-2? Now the tension is 0-1.
Characteristics of Epi springs that I found on the Internet:
- 2 1/2" Load - 86 lbs
- 1 7/16" Load - 148 lbs
I’ll leave the transmission at 21/49. It won’t be possible to quickly switch to the standard 24/50.

 

[Fords4life]

Which clutch is hotter, primary or secondary, which ever one is hotter is the one to get corrected first ....imo

 

[Yamarus]

Which clutch is hotter, primary or secondary, which ever one is hotter is the one to get corrected first ....imo

Primary clutch is hot.
There is a standard spring there.