Blowing belts

[micaelaman]

Hi,
I have an Nytro MTX 153" (2.5 challanger extreme) 2008 with MCX 270 kit. The sled goes like a rocket but eats belts for breakfast.
I bought it last year so i don't know if it setup properly.

I have a white spring in the secondary at 100 degrees and a blue-Brown-blue spring with non marked 82 grams weights on the primary. It also has a 3 mm shim between on the spring seat on the primary.

I have checked the alignment and engine position. I have also replaced worn roller bushings on the primary.

When i inspect the belt i can see that it starts to separate between the layers. This happens before it blows and i can feel it starts to slip more and more.

The record for a belt so far is 250 km.

Does any one has a tips what to do? Would an Green AC spring help? should i replace all bushings/rollers/rampshoes/springs?

 

[givemeaboost]

Are you using Yamaha belts ?


Ken...............

 

[micaelaman]

yupp only standard 8DN belts.
My Yammi dealer loves me. He grinds his hands everytime i show up.

The sled has starting to sounds a bit strange en engaging the clutch. It squeeks like it slips. This started after a ride on a trail in low speed and steady throttle and no sudden WOT.

 

[givemeaboost]

100 degrees sounds awful tight on the secondary. That much squeeze will create a lot of heat. I don't have a nitro but I have run close to 300 horse on my rx1 and only run at 70 degrees and belts last a long time. Of course we're c0mparing apples to oranges here.


Ken....,.............

 

[RED]

Same as Ken said, 1-6. Run 47 degree helix with purple EPI spring. Have this in my RX1 & Nytro, both mtn sleds turing 162 tracks. No belt issues with either of my sleds. Been on a turbo Yamaha since 2004, using oem belts.

 

[Stigapex]

The white spring is to short. You will have a coil bind if you use it in 100 degrees. Its not possible for the secondary to shift full out with white spring in 100 degrees, that eat your belts. If I dont remember wrong I think max is 80 degrees with white spring


Sent from my iPhone using Tapatalk

 

[micaelaman]

Thanks for your answers

I have a shockwave helix lying in the garage,i will try it so i can get 47 degrees. I will also change the seconadary spring to a better one, like the green AC.

I will report after my next run

 

[micaelaman]

100 degrees was to much.....
Suspect that this might have something to do with my belt problem.