catt_tracker
New member
I have a 04 mnt viper all stock. I adjusted the power valves and I am very new to clutching. I tried 2 different helixs and it made no difference at all. This is a picture of the primary weight. The primary spring is black and the seconday is black with a green mark on it.
Attachments
That is the stock primary weight but it looks like someone added extra weight to it. If you look at the top right of this page you will see "TY TECH" If you click on that it will take you to a page where you click onto "SNOWMOBILE TECH" Click that and you will see "STOCK SNOWMOBILE SPECS'' Go to 2004 and look at sx viper mtn. Scroll down and you can see that they list the weights and rivets. According to the chart your sled came with no rivet in the middle and a 10.3 weight in the tip. I would first try taking out that middle rivet (the longer one in the picture) and go from there. You rpm's will definately go up. You will probably have to do some fine tuning after that to get the proper rpm's. The type of riding you do, your altitude and clutching components will all make a difference on how you adjust that weight. Good luck.
Last edited:
catt_tracker
New member
Thanks I didn't know all that info was there!
catt_tracker
New member
So does a lighter weight make rpm go up? I just checked my secondary its a 45 degree with a black and green spring.
catt_tracker
New member
Is there anyway to test it without snow to ride on? Thanks
Yes, less weight will increase your rpms. And adjusting the rivet weights in the two different holes will adjust the rpms at different ranges in your powerband. There are so many variables that can change the weight you use like different clutch components, whether you ride on hardpack or boondock or mtn riding, altitude differences, etc.
For example I have an srx that I long tracked to 144. A friend of mine set it up for me where it worked great on hardpack but when I took it boondocking through fields with 1-2 feet of snow in it I was under revving like you are. So I had to lighten up the weight to compensate for it since that is the type of riding I normally do. You will never get it to perform perfectly in all types of riding conditions but you want to set it up for what you normally ride in.
It's pretty tough to test it without snow, even if you had a nice big stretch of grass to try it on right now your sled will be preforming different on grass than snow and even the high temperatures would make a huge difference because you would probably be running rich with your jetting thus not have as much horsepower as when it is cold and you are running at normal conditions. I'd say you have to wait until you are in the proper conditions to really be able to do proper clutching.
If I were you I would pull that middle weight and try it so you can get some kind of a base line to start at and go from there. You can tweak it some after you know where you are sitting at at that point. You can get different size rivets to try at your local Yamaha dealer to do some fine tuning if you have to.
For example I have an srx that I long tracked to 144. A friend of mine set it up for me where it worked great on hardpack but when I took it boondocking through fields with 1-2 feet of snow in it I was under revving like you are. So I had to lighten up the weight to compensate for it since that is the type of riding I normally do. You will never get it to perform perfectly in all types of riding conditions but you want to set it up for what you normally ride in.
It's pretty tough to test it without snow, even if you had a nice big stretch of grass to try it on right now your sled will be preforming different on grass than snow and even the high temperatures would make a huge difference because you would probably be running rich with your jetting thus not have as much horsepower as when it is cold and you are running at normal conditions. I'd say you have to wait until you are in the proper conditions to really be able to do proper clutching.
If I were you I would pull that middle weight and try it so you can get some kind of a base line to start at and go from there. You can tweak it some after you know where you are sitting at at that point. You can get different size rivets to try at your local Yamaha dealer to do some fine tuning if you have to.
catt_tracker
New member
Ok thanks for the info. One more question what is the best way to remove the middle weight?
A couple of bucks
VIP Member
More tip weight lowers RPM. Less tip weight increases rpm. I believe a rule of thumb is.... 1 gram=100 rpm.
A couple of bucks
VIP Member
Grind off the "bucked" side of the rivet. Then punch the rest out.
Last edited:
I've always just adjusted the jaws of my vice so that the rivet head could get through, set the weight on top and get a punch with a tip that is about half the diameter of the rivet and punched it through.
For installing new rivets I use the back, flat part of the vice. I hold the weight with the new rivet in it on there with one hand and hit the end of the rivet nice and flat with a hammer a few times to flare it. Then for extra insurance I use a center punch and give it a couple more shots to make sure it's flared enough and won't loosen up
YAMMIEGOD3:16
Active member
those weights are from a 98-99 srx. sure you can work with those. 3:16 (yammie tony)
8DN10 weights are from a 99 SRX if I'm not mistaken and as far as taking the old rivets out just grind off the side that's mushroomed out,then punch it out through the hole.If you have access to metric nuts and bolts then get some of those in 6mm,I think,whatever is closest to 1/4 inch.Get nuts with a low profile head and use the bolts to set the total weight you want.Of course you'll be needing a set of gram scales to do this too.
What I did was use a drill to hollow out the bolt to get my desired weight when combined with the nut.The reason for shallow profile nuts is that you only have so much space to work with and I had to use a regular nut and grind it down thin to work.I went this direction because my local dealer doesn't stock rivets for the weights and I didn't feel like waiting around for them to order them.
What I did was use a drill to hollow out the bolt to get my desired weight when combined with the nut.The reason for shallow profile nuts is that you only have so much space to work with and I had to use a regular nut and grind it down thin to work.I went this direction because my local dealer doesn't stock rivets for the weights and I didn't feel like waiting around for them to order them.
Clutching is where I wouldn't try to save any money. Sure, if you're on a budget, then work with those, but I'd rather just buy a set of adjustable weights with bolts, much quicker to adjust. You say that your sled is only hitting 7800, did you check the powervalves?
Yes, those are the same weights that came with my 99 srx, but if you look in the tech section you will see that they are also the stock weight that came in the 2004 viper mtn.
catt_tracker
New member
Would I be better off buying different weights and starting over? I checked the power valves and adjusted the as in the tech section using a 2.5 mm allen wrench as clearance. I have tried 2 different helixs and 2 different springs and neither made any difference at all. I also tried changing the 1,3,6,9 positions and that made no difference either. I also took it to my dealer and had them align the engine and clutches just so I knew it wasn't from the belt not being right. I replaced all 3 pistons, rings bearing and all new reeds. Factory Yamaha parts for everything.
Last edited:
catt_tracker
New member
I don't know if anyone makes weights like on my 99 skidoo 600? I really like how I can adjust them for changing conditions if I am not hitting my target rpm.
You mean adjustable weights? Hauck, Dalton and Bender do, and Heelclicker. You might have a binding issue.
Last edited:
catt_tracker
New member
So factory weights are better. I'll start by getting rid of the middle rivet.
I'd say aftermarket weights are better unless you are looking for something in particular in a weight.
What I meant is that those companies make aftermarket weights, not that they bind. If you have already checked the motor mounts and the clutch, you should take it to a dealership so they can have a look. If you have the srx motor mount and have checked the powervalves and the clutch, rpm problems like that should not be an issue.
Last edited: