blue silver blue primary spring change

[stingray719]

I broke 4 factory springs last season in my 15 stx. Dealer said that yamaha was updating the spring. I just bought ulmer clutch kit. No more screwing around.

Spring breaks because it is not strong enough, I suspect that is the reason for the new BSB to have a stronger rate but that is just an opinion.

 

[titanrcr]

BOP soft start spring was designed as a spring replacement for the Apex, so much stronger than BSB it is not even a comparison, i suggest you buy one and measure it. Increasing spring pressure even in a totally stock Viper makes better shifts, see the full details in the Clutching on the Cheap FAQ at top of this forum.

Easy....First off the Apex uses the same spring as the Viper, same color, same part number. Second, Have you ever seen or read a Yamaha spring chart because if you had you would know that here on planet earth that a GR/WT/GR won't perform anything like a BL/SL/BL or anything that is a direct replacement for it without a big change in flyweight mass. I started tuning/machining clutches and racing about 30 years ago so what am I supposed to be learning from your COTC post, Really?

 

[stingray719]

Easy....First off the Apex uses the same spring as the Viper, same color, same part number. Second, Have you ever seen or read a Yamaha spring chart because if you had you would know that here on planet earth that a GR/WT/GR won't perform anything like a BL/SL/BL or anything that is a direct replacement for it without a big change in flyweight mass. I started tuning/machining clutches and racing about 30 years ago so what am I supposed to be learning from your COTC post, Really?

LOL, go back and look at more than a few people here that went to only the stiffer spring and had great results. How about you actually contribute something of value instead of these sad and way too often attempts at an internet fight?

And YES the soft start spring has a very similar finishing rate to GWG, I will not give the exact rate as BOP owns the spring and does not want to release the numbers.

 

[titanrcr]

LOL, go back and look at more than a few people here that went to only the stiffer spring and had great results. The reason escapes you and I am not surprised. How about you actually contribute something of value instead of these sad and way too often attempts at an internet fight?

And YES the soft start spring has a very similar finishing rate to GWG, I will not give the exact rate as BOP owns the spring and does not want to release the numbers.

Yep, your right again. Glad we have you here to enlighten us all.

PS. Glad you're laughing, There's a nice group of people PMing each other laughing at you........nothing more to say

 

[stingray719]

Yep, your right again. Glad we have you here to enlighten us all.

PS. Glad you're laughing, There's a nice group of people PMing each other laughing at you........nothing more to say

"How about you actually contribute something of value instead of these sad and way too often attempts at an internet fight?"

 

[stingray719]

Sr viper stock primary spring Blue Silver Blue has been updated same pre load and rate just 2mm thicker.
Also different part number, I just ordered one going to check it against my original one.

If you get real curious you can find the difference between the two by using this calculator http://www.pontiacracing.net/js_coil_spring_rate.htm
I used a similar calculator back in my stock car racing days as we had many springs and it is hard to keep them tagged.

 

[gpxsrx]

Please don't make this snowmobile forums like others out there.

 

[Allan]

And YES the soft start spring has a very similar finishing rate to GWG, I will not give the exact rate as BOP owns the spring and does not want to release the numbers.

This finshing rate is way higher than stock spring. Well this work in stock machine with out changing clutch weights ? Would this would make the stock clutch over Rev?
So the pre load must be lower than stock to get lower RPM at start?
Now knowledgeable on this so just asking questions.

 

[stingray719]

This finshing rate is way higher than stock spring. Well this work in stock machine with out changing clutch weights ? Would this would make the stock clutch over Rev?
So the pre load must be lower than stock to get lower RPM at start?
Now knowledgeable on this so just asking questions.

Works well in stock, I believe notenoughtoys installed on stock on the first page of this thread, maybe he can reply again. I have not seen it make the stock clutch over rev but it is possible, in fact as your Viper gets miles on it you will probably have to add weight to your stock clutch no matter what you run.

 

[gpxsrx]

Spring has same initial force 35 but does not give final rate in the spec book, different part number but same color

 

[Notenoughtoys]

Stingray, I did install them on both vipers with stock clutching. Only ran them on the stand and noticed smoother engagement then stock springs. Waiting for snow so I can get some seat time.

 

[gpxsrx]

Anyone have a chance to measure finish rate of the new BL SIL BL primary spring ?
I have the spring but not a spring tester.

 

[stingray719]

Anyone have a chance to measure finish rate of the new BL SIL BL primary spring ?
I have the spring but not a spring tester.

Can take out your micrometer and measure spring coil thickness, then length and most important number of coils and tell that way. Can also plug those numbers into here http://www.pontiacracing.net/js_coil_spring_rate.htm

 

[billymx815]

Why bother, put in a Barn Of Parts soft start spring and engage at 2600 rpm

I just put one of BOP in my wife's viper and what a difference with engagement. Went from a neck snapping 3400rpm engagement to a 2600-2700. So much easier for her to trail ride now.