Trying The 8DN BELT

[fxnytroxtx]

Anyone tried to put a shim between the helix and the secondary, some say there's about 5mph to be had with this little cheap mod?

 

[YamahaTim]

Ya like a speed ring

 

[NOS-PRO]

Well Yamaha Tim and Nos Pro, put on the new 8DN and wow what a difference. The most I ever got out of the sled was 99 mph now with the new belt I've hit 101 mph. Had a hard time to get to 99 and now hit 101 mph with ease. Never had a Yamaha belt sit low in the secondary before I knew something was wrong with the belt and now everything has become perfectly clear the Viper has the wrong belt in it. Running with that belt makes the sled better to drive. Only had time to put on about 50 km on that belt so far but the sled feels awesome and pulls so much stronger. Definitely made a big difference on my sled. Thanks again guys for all your research

Rxviper - No worries bud!

I, YamahaTim and many of the viper owners were not happy with the way the Viper was inconsistant in rpm's, top speed and performance. There had to be something in the clutching as there couldn't be that much difference between engines. I am so glad we (all of us here) could come up with some answers

Stayed off of TY yesterday to do some much needed family time. Early morning ride with family on the sleds to The Smiling Moose tavern to have an incredible breakfast! After that, it was a very nice 75 mile ride to see the best trails and sights I have seen in my area in years! All the while, the viper was running perfect, very smooth engagement, good pull and just having a great time!

This 8DN changed the whole aspect of the sled and in return, made my Nytro even quicker and faster.

Will be doing more and more testing on belts, gearing and of course clutching. As for now, the sled rocks and couldn't be happier

 

[NOS-PRO]

I wonder if I would see any gain by shimming my stock viper belt? I noticed from day one that it sits low in the secondary. My turbo viper is flying but still get inconsistent rpms in deeper snow. I might shim it and run the stock belt and then try the nytro belt.

I agree with YamahaTim, the belts are just sliping, plain and simple. I've tried to shim, scuff the cluthes and belt to make it perform and it just won't grab.

 

[NOS-PRO]

A couple things that I have been wondering for you clutching experts.

1. Any chance the factory belt is different quality than the one you buy over the counter at the Yamaha dealership.

2. If the 8DN is longer how can you get full shiftout when both clutches are at full engagement.

sxr70001 - It is the manufacturer of the belts that is the problem. The compound of materials is too hard making the belt slip.

The clutches are grabbing the belt now and getting more shift out.... But I know what your thinking and I am also. I am trying to find a belt that is 1110-1115mm in top overall length with a good compound.

This 8DN works right now and has fixed many over-revving problems and top end speeds have increased, but I think a smaller belt will bring this Viper to over 105mph. My top speed with the 8DN and my clutching is 105.1mph (still on my GPS). I do not believe I am getting total shiftout.....but it's close

 

[09nytro]

What about a gates belt ?
They make one for the viper , I have one coming , should be here this week !

I see them on e-bay for 69 with free shipping !

 

[NOS-PRO]

I thought about that when I was looking at Viper parts. I might have to try one!

 

[stingray719]

I thought about that when I was looking at Viper parts. I might have to try one!

See my post on the Gates belt, I tried the equivelant of the 8DN. I might have had a bad one as I pulled it off the shelf and have no idea where it came from, but low speed squeeling and loss of power. Put old 8DN back on and back to rockin.

Problem I saw with Viper belt was lack of horizontal strength and smaller contact surface, let us know if Gates Viper belt has fixed that, but I for one am not leaving the 8DN at this time.

 

[09nytro]

I thought about that when I was looking at Viper parts. I might have to try one!

I was looking at the specs and it's 36mm W and 1124 mm long , I figured what the hell I'll give it a try , Can't hurt !

 

[YamahaTim]

I thought about that when I was looking at Viper parts. I might have to try one!

I was looking at the specs and it's 36mm W and 1124 mm long , I figured what the hell I'll give it a try , Can't hurt !

Good, let me know how it worked out!

 

[NOS-PRO]

I thought about that when I was looking at Viper parts. I might have to try one!

See my post on the Gates belt, I tried the equivelant of the 8DN. I might have had a bad one as I pulled it off the shelf and have no idea where it came from, but low speed squeeling and loss of power. Put old 8DN back on and back to rockin.

Problem I saw with Viper belt was lack of horizontal strength and smaller contact surface, let us know if Gates Viper belt has fixed that, but I for one am not leaving the 8DN at this time.

I remember you tried the Gates belt and didn't have luck with it. Was the number 40G4313? Now I see there are some other belts like a C12 8DN equivalent and some others IPC maybe?

Thsi 8DN worked and happy with it, but I have to tinker to get best results

 

[stingray719]

I thought about that when I was looking at Viper parts. I might have to try one!

See my post on the Gates belt, I tried the equivelant of the 8DN. I might have had a bad one as I pulled it off the shelf and have no idea where it came from, but low speed squeeling and loss of power. Put old 8DN back on and back to rockin.

Problem I saw with Viper belt was lack of horizontal strength and smaller contact surface, let us know if Gates Viper belt has fixed that, but I for one am not leaving the 8DN at this time.

I remember you tried the Gates belt and didn't have luck with it. Was the number 40G4313? Now I see there are some other belts like a C12 8DN equivalent and some others IPC maybe?

Thsi 8DN worked and happy with it, but I have to tinker to get best results

Belt is 40G4340 the old replacement for 8DN I believe.

BTW brother still has a Vmax 4 he doesn't use if you need another

 

[Tarzan]

little tip. Take a permanent marker and make a line on the inside of the primary and secundery to see how the belt travel.

 

[NOS-PRO]

I thought about that when I was looking at Viper parts. I might have to try one!

See my post on the Gates belt, I tried the equivelant of the 8DN. I might have had a bad one as I pulled it off the shelf and have no idea where it came from, but low speed squeeling and loss of power. Put old 8DN back on and back to rockin.

Problem I saw with Viper belt was lack of horizontal strength and smaller contact surface, let us know if Gates Viper belt has fixed that, but I for one am not leaving the 8DN at this time.

I remember you tried the Gates belt and didn't have luck with it. Was the number 40G4313? Now I see there are some other belts like a C12 8DN equivalent and some others IPC maybe?

Thsi 8DN worked and happy with it, but I have to tinker to get best results

Belt is 40G4340 the old replacement for 8DN I believe.

BTW brother still has a Vmax 4 he doesn't use if you need another

Thanks bud....

What kind of V-max 4? My stable is kinda crowded right now, but will definitley spread the word!

 

[YamahaTim]

little tip. Take a permanent marker and make a line on the inside of the primary and secundery to see how the belt travel.

Ya I know just getting my sled back tomorrow. Just a simple fix! Nothing wrong with the motor? I will do that test soon! Thanks