Best belt for my sled ?

[Snowmobile Mike]

No. Get another Gates for spare. 8dn is different size and compound.

I'm not a full throttle Guy , My Pooh FST had about 3000 miles on it before I changed for safety. I'm sure if I got in a pinch the 8DN would get me home , No ?
I don't like to spend when I don't NEED TO ,I just ordered 8DN, I probably could sell it, I'd like to GET BY THIS YEAR ,I only put 600-700 Miles a year anyway since I'm in CT and have to travel to Vermont,Maine or N.Y. to ride !
Thanks for all your input it's appreciated, Thanks again Mike

 

[cannondale27]

I'm not a full throttle Guy , My Pooh FST had about 3000 miles on it before I changed for safety. I'm sure if I got in a pinch the 8DN would get me home , No ?
I don't like to spend when I don't NEED TO ,I just ordered 8DN, I probably could sell it, I'd like to GET BY THIS YEAR ,I only put 600-700 Miles a year anyway since I'm in CT and have to travel to Vermont,Maine or N.Y. to ride !
Thanks for all your input it's appreciated, Thanks again Mike

Use your stock 8jp for spare and sell the 8dn. Last thing you will want to be doing ifbelt blows is messing around adjusting clutch for a 8dn.

 

[Snowmobile Mike]

I found similar results. 8DN good upgrade for NA motor. When I went turbo, I also got better performance going back to the 8JP length, but I have been using the Ultimax XS825 with very good results.

What is NA motor ?

 

[Snowmobile Mike]

Another thought I just had is belt width..people have complained from the start about the harsh engagement of the viper and a huge factor in that is the belt to sheave clearance. When comparing a Yamaha belt to a gates belt, the yammi belts are narrower, not a huge amount but it is noticeable. So with a narrower belt when your weights overcome the spring pressure and engage the belt it’s not a smooth transition with the narrow belts because the larger gap between the belt and sheaves makes the clutch “slam” into the belt so to speak. Now different springs and weight profiles can alter this and improve it..but the issue still exists. The 911 cover that you can adjust that clearance would be a great option. I don’t have one nor have I ever used one, but the concept and idea is great..another great idea is simply a wider belt. If you’re into taking comparison measurements, try some different belts and and with a feeler gauge check the clearance on the primary clutch between the belt and sheaves. On mine with the gates belt and .018 gauge fits and a .020 gauge does not, that’s right in the desired range. Even with yamaha’s Stiffest primary spring with my weights and roller setup my engagement is 2300 and very smooth..but the kicker is that when it engages the sled instantly starts to move, no belt slack to overcome and no belt slipping with the gates.

 

[Snowmobile Mike]

What is 911 cover

 

[BFS]

NA-Naturally aspirated, aka, no turbo or supercharger. The 911 cover is an aftermarket primary cover that is adjustable for tighter belt clearance for the primary, it’s a Thunder Products item.

 

[Snowmobile Mike]

NA-Naturally aspirated, aka, no turbo or supercharger. The 911 cover is an aftermarket primary cover that is adjustable for tighter belt clearance for the primary, it’s a Thunder Products item.

Thanks ,I will check it out !❄❄

 

[twyztid]

I have not ridden mine with the MPI turbo yet. Is 8800-8900 the target RPM at full shift out? The clutching was already setup by STM but I do not know at what RPM. It still has the stock 8JP belt on it (46 miles on sled) but I just got 2 of the Gates 8JP carbon fiber belts. I have read that it will lower the RPMs compared to the stock 8JP belt. Was it something like 200-300 RPMs?

 

[cannondale27]

Vs 8dn gates is almost 300rpm. 8jp might be less depending on condition of it. 8800-9000 is ok. 9100 would be better!

 

[twyztid]

Vs 8dn gates is almost 300rpm. 8jp might be less depending on condition of it. 8800-9000 is ok. 9100 would be better!

I was referring to the Gates carbon 8JP belt vs an OEM 8JP belt with very low miles on it (46 to be exact).

 

[cannondale27]

I was referring to the Gates carbon 8JP belt vs an OEM 8JP belt with very low miles on it (46 to be exact).

Gotcha. Havent tested that combo.

 

[twyztid]

Gotcha. Havent tested that combo.

Seems like it would be much closer than the OEM 8DN to Gates 8JP since the OEM 8JP is already softer than the 8DN

 

[Fast]

L

Another thought I just had is belt width..people have complained from the start about the harsh engagement of the viper and a huge factor in that is the belt to sheave clearance. When comparing a Yamaha belt to a gates belt, the yammi belts are narrower, not a huge amount but it is noticeable. So with a narrower belt when your weights overcome the spring pressure and engage the belt it’s not a smooth transition with the narrow belts because the larger gap between the belt and sheaves makes the clutch “slam” into the belt so to speak. Now different springs and weight profiles can alter this and improve it..but the issue still exists. The 911 cover that you can adjust that clearance would be a great option. I don’t have one nor have I ever used one, but the concept and idea is great..another great idea is simply a wider belt. If you’re into taking comparison measurements, try some different belts and and with a feeler gauge check the clearance on the primary clutch between the belt and sheaves. On mine with the gates belt and .018 gauge fits and a .020 gauge does not, that’s right in the desired range. Even with yamaha’s Stiffest primary spring with my weights and roller setup my engagement is 2300 and very smooth..but the kicker is that when it engages the sled instantly starts to move, no belt slack to overcome and no belt slipping with the gates.

NA-Naturally aspirated, aka, no turbo or supercharger. The 911 cover is an aftermarket primary cover that is adjustable for tighter belt clearance for the primary, it’s a Thunder Products item.

Are you sure this is a primary adjuster or is it for the secondary to control belt deflection.

 

[Fast]

Another thought I just had is belt width..people have complained from the start about the harsh engagement of the viper and a huge factor in that is the belt to sheave clearance. When comparing a Yamaha belt to a gates belt, the yammi belts are narrower, not a huge amount but it is noticeable. So with a narrower belt when your weights overcome the spring pressure and engage the belt it’s not a smooth transition with the narrow belts because the larger gap between the belt and sheaves makes the clutch “slam” into the belt so to speak. Now different springs and weight profiles can alter this and improve it..but the issue still exists. The 911 cover that you can adjust that clearance would be a great option. I don’t have one nor have I ever used one, but the concept and idea is great..another great idea is simply a wider belt. If you’re into taking comparison measurements, try some different belts and and with a feeler gauge check the clearance on the primary clutch between the belt and sheaves. On mine with the gates belt and .018 gauge fits and a .020 gauge does not, that’s right in the desired range. Even with yamaha’s Stiffest primary spring with my weights and roller setup my engagement is 2300 and very smooth..but the kicker is that when it engages the sled instantly starts to move, no belt slack to overcome and no belt slipping with the gates.

So what belt clearance are we looking for 10 -18 thou. From my poo experience I think the sweet spot was 10 thou.

 

[cannondale27]

So what belt clearance are we looking for 10 -18 thou. From my poo experience I think the sweet spot was 10 thou.

I run mine at .008in feeler guage