MCX Nytro secondary clutch problem

[BigFish BC]

i use 1-0.any snow getting on your clutches?

 

[summitboy]

Thistle, is the 47 helix the helix most people use on the Nytro ?

 

[Mcx Nytro]

What weights and Helix are you using with boost? So is the purple spring longer, but set at 0/1 it has no more torsional force than the pink Yamaha spring that comes in the Nytro? What about the Dalton secondary spring? His website says it has teh same torsional force as a silver spring, but is 1/2 inch longer for more side force.

I am running the 8bu fully loaded with a shockwave helix set at 51 for now. I amd going to try the daqlton wieghts as I am over-reving and I prefer to control the rpm with the primary and the shift with the sec, the cat purple is holding up for now but I will replace it with a ti spring for a longer life....02

 

[Mcx Nytro]

I'm running a straight 47deg helix. THe snow was really dense and deep. Seemed like ever time I gave it a jab...when the boost rose....it would slip. Something is weird...worked for 3 days and then I got snow on my belt....roasted it. Installed a new one for the next day and the issues started to rise??

What primary set up are you using? What boost? cause at 14 lbs boost i am easily pulling a 51 loads the motor quickly better hookup on belt....450 ks and no problems except for keeping the front end down

 

[robertyoke]

I seeing some of the same problems. in sissy snow the clutching works but in real deep snow the belt/clutching is getting way too hot!

I put a purple ac spring and it was better at keeping the secondary from holding the belt at the bottom. I then tried a purple and white ac spring and it took 2 men and a boy to twist it in place and put the nuts on. I added some lincoln weight on back of the 8bu's to get them to 61.7 grams. it is better but i still see the heat being a problem. I also see the rpms drop on long climbs still but its getting better. starts at 9000 then will drop too 8500/8600 the hotter clutches the worse it gets. I saw 8300 several times and the clutches were hot!!
I ordered some thunder shift ramps (almost same profile as the 8bu's but 64 grams to start with) I going to try an stiffer primary spring and stiffer secondary spring this weekend. then load the ramps in hopes to get more squeeze and less slippin on the belt.
yamaha is sort of limited to the selection of springs to chose from compared to the other 3.
-robert

 

[Thistledoo]

I'm using the 8BU's fully weighted and the 14.5mm rollers and yes the clutches are smokin....but look at the snow we were bustin. THe weird thing is I put the epi purple spring in and it ran great for 2 days in the bottomless fluff. THen I roasted the belt (snow I think) so day 3 I put on a brand new belt. Easy trail ride for 10 miles and it started doing the drop into the back again.....weird but the snow was really deep and dense. Guess I will put it together again and see if I can get one more hole on the helix. It just seems to up shift way to fast if you give it a crack and the boost comes on. Maybe the 47 isnt enough?? Wheres the best place to buy a shockwave?? And how do you know where your at for degrees once you start adjusting it?

 

[PUNISHER]

Shockwave starts at 40 degrees and every full turn out from fully seated is 4 degrees. So a quarter turn on the adjustment dial is 1 degree.

Not sure on the best place to buy one. Got mine from Outlaw Motorsports.

 

[summitboy]

I know i run a straight 51 regrind for my Apex. Are others running a 51 in their Nytro's ? Just curious.

 

[robertyoke]

I'm using the 8BU's fully weighted and the 14.5mm rollers and yes the clutches are smokin....but look at the snow we were bustin. THe weird thing is I put the epi purple spring in and it ran great for 2 days in the bottomless fluff. THen I roasted the belt (snow I think) so day 3 I put on a brand new belt. Easy trail ride for 10 miles and it started doing the drop into the back again.....weird but the snow was really deep and dense. Guess I will put it together again and see if I can get one more hole on the helix. It just seems to up shift way to fast if you give it a crack and the boost comes on. Maybe the 47 isnt enough?? Wheres the best place to buy a shockwave?? And how do you know where your at for degrees once you start adjusting it?

I got mine from http://www.shockwaveperformance.com/order_page.htm

I know its deep, but I think there is some room to make the clutching better. I have half the hp in my king cat yet heaver ramps. the 8dn is a very hard belt and I think it needs some serious squeeze to keep it from slipping with 230 horses yanking on it. I think the heat is killing the springs, might have to upgrade to titanium when I figure out what works.
-robert