Blown Belt

[snowbeast]

As was mentioned.... .070" machined out of the spring pocket on the fixed sheave where your secondary spring sits in by the 3 spring tab holes. Only have to machine the fixed sheave spring pocket.

But also machined were the hub on the helix and machined the fixed sheave to allow the sheaves to come together for the 8DN belt I will be testing soon.

OK so you machined .070 thou deeper,and slightly larger dia. than the spring is of course,on fixed sheeve only,but than you also did the movable sheeve thinking it will help for the shift out on the 8DN belt?

 

[Snowaddict]

From what I can see,you have not even opened it up yet,why? You bought one of the fastest production sleds ever built,dont you want to go fast,and if you say I am breaking it in by the book,than go reread the books statement,no long term full throttle runs,it don't say you cant open it up,from day one,it just states to not hold it there for heat issues in the motor department,so go out and run it hard for 6-8 second blasts or until it shifts fully,and I bet that's not going to take more than 5 seconds on hard pack. What we see is just out of nuetrul is where you are most of its time so far.Am I wrong?

Fastest production sled is exactly why I bought it Beast. Break in and now fear of belt blowing has caused my hesitancy. Point taken. I hate disappointing my Yamaha brethren. Hopefully, clutching issues get figured out. You guys are doing a great job at this. I'm subscribed.

 

[NOS-PRO]

OK so you machined .070 thou deeper,and slightly larger dia. than the spring is of course,on fixed sheeve only,but than you also did the movable sheeve thinking it will help for the shift out on the 8DN belt?

Nope, only the fixed sheave gets machined for the coil bind and 8DN. Just .070" deeper and enough clearance for the spring

 

[snowbeast]

Fastest production sled is exactly why I bought it Beast. Break in and now fear of belt blowing has caused my hesitancy. Point taken. I hate disappointing my Yamaha brethren. Hopefully, clutching issues get figured out. You guys are doing a great job at this. I'm subscribed.

Brother I will feel just like yourself if I start blowing belts,but want to make sure its not from my tune I am about to throw in there,sense its all apart. But I do remember doing some of this washer shimming to get more OD,but in our case sled don't need more overdrive,it needs reliefe,spring reliefe lol like NOSPRO wrote,relieve spring pocket,that will be the best solution,or cheap out guys,can shim it,so its has room before it plans on binding.

 

[snowbeast]

Nope, only the fixed sheave gets machined for the coil bind and 8DN. Just .070" deeper and enough clearance for the spring

Hey NOS-PRO have you tried a viper secondary yet,some guys have with great results,i realize it wont fix our problem,but I bet it solves the spring binding issues and roller issues lol

 

[dsimonRX1]

Leaving early tomorrow morning so I took 3 washer, sanded a flat edge to fit in helix and then put them on the surface grinder to make them identical in thickness. I will report how this works as early as tomorrow night. I have the TD turbo force, TD Ecotrail, Dalton weights from TD and 192 - 1.52 INS stingers. I also have my wife's Viper with me if I need to try that secondary.

 

[NOS-PRO]

Hey NOS-PRO have you tried a viper secondary yet,some guys have with great results,i realize it wont fix our problem,but I bet it solves the spring binding issues and roller issues lol

Yes, I have put the Nytro/Viper secondary on with good results because I can run any of my previous helix's.
(Pic is a clutch from a nytro I had in the shop to show that they do fit and will work)

But, the Nytro/Viper secondaries also coil binded.....

 

[Jafo1970]

Any help on how to measure offset? Where you measuring to get 58.1 to 61.1. I've always just used a straight edge.

 

[NOS-PRO]

Any help on how to measure offset? Where you measuring to get 58.1 to 61.1. I've always just used a straight edge.

Straight edge on the front of the sheave of the secondary to the rear sheave of the primary. Caliper works well, or if you have a tape measure to see if you are close.

I should start machining an offset gauge.....

 

[**sj**]

nos, and the ctc spec?

 

[shagman]

nos, and the ctc spec?

Ctc isn't adjustable on this chassis with the 4 stroke. It is what it is. Otherwise we would just change it to run the 8 dn belt.


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[snowbeast]

I haven't experienced any belt issues yet however I haven't pinned it either.

From all the threads it seems like something is not right in the secondary spring when I put it back together sure don't seem to fit well.

I don't like these junk cast helix either.


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The guys who may exsperiance issues,will be guys running full throttle,more than 1/2 throttle,its when the primary trys to ift it thru the secondary,and the secondary saids enough,i cant take any more,or like your wife lol,well I have never had that problem with my wife lol,but anyways,the secondary spring has to do two things,one compress and the other twist to keep side pressure on belt,but the spring pushes against its self hard enough,while it trying to shift out,or accept all the belt the primary wants to give it,it may bind up,and build up lots of heat and if you don't know its getting hot,and kep pushing that belt somewhere it don't want to go..Bam! So remove your primary spring,and reinstall the cover,now go to secondary,remove helix and spring,reinstall helix,with all bolts in each clutch,install your belt,have some one help you if needed,open up the secondary all the ways,and close the primary onto the belt all the ways,have some one hold it in position,and snap a pic,send it over here so we can look at it,and also measure,with a black marker on both clutches where belts rests. And reread your manual from Yamaha on motor break in,it does not say you cant pin throttle,it saids no WO throttle for extended lengths of time,you can pin it for seconds to a time in the very first mile or less,just blast it than ride it for a few 100 feet easy and blast it again,and each time blast and hold a tad longer till you have 15-20 miles on it,there is better way to set your rings than this,after my first mile drag racing we had 8800 rpms all stock,you should to.

 

[Jafo1970]

Straight edge on the front of the sheave of the secondary to the rear sheave of the primary. Caliper works well, or if you have a tape measure to see if you are close.

I should start machining an offset gauge.....

Thanks. Just wanted to make sure. Is there a spec for CC? I know its not adjustable but either was the cat turbos and those pretty much all ran long enough to run a longer belt to help.

 

[Jafo1970]

And I have no scuff marks or paint removed on my secondary spring. All my cat rollers touch the helix with belt on. Clutches have been cool, just warm.

 

[Fleecer]

Is that with the single shim it came with?

Yes