Clutching on the cheap

[Studroes144]

Yes there is no doubt a lot to clutching, I'm no pro but have seen it enough to know that no two sleds are the same and without a ton a weights and springs at your disposal you can be spinning around in circles and may never get it right. I will say that with the proper springs and a more aggressive weight, the potential is there to have a sled that is a rocket, but so many times there's such a fine line between running spot on and running close and that kinda setup will always have you right on the edge of a yay or nay setup. It's just not a safe bet at all to say a clutch setup for someone at 8000 feet that rides powder is going to work for a trail rider that rides at 1000 feet.

 

[RTX]

No, I know about the belt deflection washers. I think it was Nos Pro that said he used washers to space his helix out so the spring coils wouldn't bind. I just cant picture where he put them.

You need to put them under the helix in the secondary clutch.
On the bolts Between the bolt hole mounts on the helix and the clutch. They move the helix further away.
I bought mine from mcmaster carr.
If i remenber right he said .060 shims.
I bought shims that were .020 each. I put 3 on each bolt

 

[shagman]

I run .090 shims. on mine.

 

[RTX]

$228 for weights that have no adjustment I'd say is a rip off. I have a few sets of magnaforce weights from D&D, none are for sale, but they are $200 for a set of 3, they can be adjusted for a sled anywhere from prolly 120hp all the way up to close to 200hp simply by adding or taking away magnets, they're simple to adjust, the problem with a clutch setup that has no adjustment is that if it works at 1 elevation where a sled is making say 120 hp, it's not going to work for a sled at a different elevation making 130hp..let's say in the future you add a can or intake or something to increase power, if you don't have adjustable weights you're stuck trying to find a different spring rate to work. If you're into a do it yourself set up and don't have a lot of available springs id highly recommend an adjustable weight. Huge range of adjustability and in comparison are cheaper than a none adjustable weight

The yamaha weights he bought are adjustable. They have 2 holes in them for rivets. You can buy different weight rivets and add weight in the tip or heel
Maybe not as easily adjusted as the weights you use but they can be adjusted.

I purchased my weights for like 40-45 bucks each brand new. Rivets are about a buck or so each.
Really not an expensive mod

 

[RTX]

Th

I run .090 shims. on mine.

that might be what i am running too.
Just going off memory and my memory aint so good any more. Lol

 

[RTX]

i thought it was 8 FP weights for the "NOS PRO clutch" ??

Ok now you have me guessing because prices are way off .
Didnt stingray use the 8fs and nos use the 8fp?

 

[sxr70001]

Cool, thanks to everyone. Lots of great discussion. I'm certainly not an expert at clutching either, but I find if I can use someones setup to get close I can fine tune it the rest of the way. Just having a starting point from all you guys with more experience is a great help.

 

[cannondale27]

For that price I also would recommend a clutch kit. I was happy with my Ulmerkit after some fine tuning and switching to 8dn. His weights are also easily adjustable.

 

[RTX]

I just looked back at the original posting on this clutch mod.
Nospro is running 8fp weights with a 3 gram rivet in the tip
I also bought 8fp and they were 36 bucks each.
Sting ray runs 8fs in amountain sled set up.
Hope i you got the correct weights ordered

 

[viipeR]

thats what i did mine with..... 8FP's, 3.5 gram tip rivets, 8DN belt with appropriate shims. G/W/G primary

 

[stingray719]

Ok now you have me guessing because prices are way off .
Didnt stingray use the 8fs and nos use the 8fp?

Correct, both weights are almost identical but 8fp are ALOT cheaper. 8FS weights came in all the Yamaha mountain models. I bought a used set of 8fp from hibshman25 (he is a used parts vendor here) on this site for $75.00 for our second Viper.

 

[sxr70001]

Thanks guys, changing my order.

 

[stingray719]

Yes there is no doubt a lot to clutching, I'm no pro but have seen it enough to know that no two sleds are the same and without a ton a weights and springs at your disposal you can be spinning around in circles and may never get it right. I will say that with the proper springs and a more aggressive weight, the potential is there to have a sled that is a rocket, but so many times there's such a fine line between running spot on and running close and that kinda setup will always have you right on the edge of a yay or nay setup. It's just not a safe bet at all to say a clutch setup for someone at 8000 feet that rides powder is going to work for a trail rider that rides at 1000 feet.

Barry sorry to say a clutch set for 8000 feet WILL work fine for the same sled at 1000 feet with only a rivet/weight adjustment. Case in point is NOS-PRO has the same setup as my powder sled except the amount of weight on the primary clutch weights. Please don't confuse clutching more than it already is.

Also, the profile on the weight is more important than even the amount of weight. That is why NOS-PRO and I run a flat profile weight as Shagman mentioned. And it does matter if the weight is in the tip tip or the base of the weight, I will let Shagman explain that part. There is definatly more than one way to set a clutch and have it work, but we are offering a setup that is cheap and does work and we are not trying to help any vendor.

 

[stingray719]

All weights are not the same. the profile of the weight plays as much of a role as what it weighs. A weight with a lot of curve will pull rpm's down with less total weight, than a weight with a flat profile requires more mass to do the same thing. This also depends on the torque of the motor being clutched. There is lot to clutching.

Agreed, one of my experiments was to take the stock Viper weights and grind off the little bump on the base of the ramp that causes the Viper to rev higher at take off. The bump is very beneficial to 2 strokes as it makes them rev higher to take off but not so much value for a torque engine like the Viper. Ayways, taking the bump off the ramp had it act like the 8fs/8fp weights. Just an experiment though as the 8fp were bought for this sled.

Also fun to note the 8fs came on all the 4 stroke mountain sleds as us powder riders do not like the engine to rev up and slam the clutch in on takeoff

 

[sxr70001]

Not trying to start anything and you can never have to many tuning parts. I trust you guys and you have all helped me over the last year.

Studroes was one of the first guys to have a viper and tear it down and let a lot of us know about things he found to check and fix before hitting the trail and he has proven to be a stand up guys willing to help, but in this case he says he has adjustable weights and different springs from stock, but that's not enough detail for me to mimic and I'm just not ready to buy someone else's clutch kit at this point. I like to try it on my own first, must be a character flaw.

I also have followed Nos Pro and Stingrays journey with the clutching and what not so I trust them too. I also know I have to do my own work to get what I want out of my sled. So I will try this and see what I end up with.