Viper clutch parts advise

Robbe144

Robbe144

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Joined
Dec 13, 2011
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39
Location
Sweden
Hi!
Thank you for a really good forum

I have a piped viper with some issues..
The backshift has become worse and worse. At first I noticed a little poor backshift, but I didn't ride as much deep snow then as I do now.
I have changed all the bushings and cleaned the clutches, no improvement.
Now I have the secondary winded up all the way (9-3 120 deg, I measaured tourque approx 20Nm) and it's better but not good, when I need the backshift the most - in deep snow, it's not there.
The upshift has always been good until now when I started to stiffen the secondary. If I push the throttle rapidly and don't keep an eye on the tach it over-revs until the shift-out appears.
So now I have two problems, but smaller.
Engagement rpm approx 4500, top rpm 9000, ok for me.
The sled has a heel clicker kit in the primary, red spring, bolts in the shoulder, nothing in the middle or tip. Green spring in the secondary (black spring, green markings), 42-36 helix. Track with 2" lugs, 8t sprockets.
Now it feels like I need a stiffer secondary spring for better backshift and more weights for the lack of upshift?!

I want it to work best in the deep snow. I tried a similar machine with stock pipe/silencer, - Up on viper sound and it just floated on the snow, worked great.

Can you advise me what to buy/do/change?
Thanks
Robert, Sweden
 

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Got a good tip, removing weights from primary and loosen secondary. Tried that today and now it feels like the problem is going to be solved. :)
Does anyone know where to get a set of screws and washers for my heel clicker weights?
(or wich ones that fits)
 
what pipes are you running? whats your gearing? what type of helix are you running? sled looks awesome!! interested to see becaues i am going for the same type of set up.
 
Thanks for the info about bender. Passed M Performance today and he had an almost complete set!! :)

My pipes are marked Hauck and look like pic. (shape not condition :) ) Stock gearing so far, used large gear and chain are $100 each here.. Helix as above
 

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Thanks :)
I'll try and get it to work the way I want.
I moved pipes, carbs, clutches from another sled who worked fine. Maybe a little low on backshift in deep snow but good on trails.
So I figure I can't be that far from target, but they don't work the same that's for sure.
 
You say it has gotten worse...do you mean you got the sled with the triple pipes, 2" track and 8 tooth drivers already on it and it used to backshift better but now doesn't? Or do you mean it has gotten worse as some of those modifications were done to it? If the former, then you need to look for something in the clutching that has worn and is causing the issue. Worn rollers, flat spots on the buttons, sagging springs, and belt deflection from worn wear bolts on the back of the secondary or a worn belt would be a place to start, as those are all things that wear and can change.

Stock short track vipers came with a 1" track, 9 tooth drivers, and 22-38 gearing. So yours is going to react a lot differently from a stock one, since you have 8 tooth drivers and a 2" track (let alone another 25-30 hp from triple pipes). Your gear ratio will be different with the 8 tooth drivers, and your gears have probably been changed as well. With that being said, a lot of weight in the primary arms doesn't make for a great back shift in my experience. I'm no clutching expert by any means. It is a fine line to get that instant snappy backshift that is nice in powder and yet still puts the proper load on the motor. From what I read on this site your set up is great for short tracked sleds looking for great acceleration and top end pull. Not so much for a deep powder application though, unfortunately we can't have both. I have a 144" track, so I can't just tell you my set up and have it work for you. Someone like MrViper or snowdad could probably recommend a set up that will be more of a compromise between a trail and powder set up. It may even require going away from the heal clickers, as I've read that they are a very aggressive racing weight. To get better powder performance you will give up some trail performance though. A good example is my cousin's sled verses my sled. He has a SRX with a 141" track (which is also ported and polished, has aftermarket reeds, and anti-ratchet drivers) and I have a piped Mountain Viper. My cousin has his set up for drag racing and mine is set up for powder and climbing. My cousin's sled will absolutely torch mine in a drag race, he gets me by like 8+ sled lengths...but his can't touch my sled climbing in powder. His is geared and clutched to shift out quickly and reach top speed as fast as possible, and mine is geared and clutched to hold the maximum speed it can under load in powder when climbing. His gets about 38 mph track speed when climbing, while mine gets 50 mph track speed.
Sorry for the long post, I hope it helps you out.
 
Thanks Mr V! And thanks for all the information you freely share here. I've learned a ton from your posts over the years, and that combined with my own experiences has really helped me to keep my sled on the snow and performing the way I want it to.
 
Thanks, should have explained better.
I shifted clutches, carbs, pipes and some other stuff from another sled to this one. The backshift feels worse on this than the other. Naturally because it's different sled, and I think the other one was ported too. I'm new to clutching but listening and willing to learn.
I have changed all bushings big and small, changed to sliders with o-rings in the primary and also changed the small plastic ones that slides on the helix.
Checked weights rollers etc. What I haven't checked are the condition of the springs, not sure how either.

I have tried stiffening secondary as mentioned above, didn't work. Now thinking of going back on the secondary and try lighter weights in combination and see how that works. I weighed the bolts that were in the weights and they are approximately 10gr together.
I understand that that I maybe have to leave the heel clickers, but I would like to give them some more time first.
Again, thanks for all the input :)
 
Reading this from the start, i am a little bit confused. you say its got 10 grams of weight in the arms but at first you said it just had heel weight. Reason i question that is , you cant run 10 grams just in the heel, so need to understand what extra hardware is in the weights, heel weight, middle hole and tip hole.
The h/c weight is very aggressive upshift, youd need heel weight to get the engagement down to keep from trenching, your top rpm needs to be about 9100-9200rpm with those pipes.

with 8 tooth drivers and stock 22/38 chaincase gears you would be at 1.94 ratio, did you use the same set up in the other sled?
 
The 10 grams (all 3 screws total) are in the shoulder/heel. Mid and tip empty
Yes the other one was also 22-38 and 8t drivers.

Ok! So 9200 is alright, I thought that was over-rev and was aiming for 9000
 
robbe144, when you refer to heel clickers just talk about one weight versus three that you are trying to explain. So for instance, what you are running to my understanding is red spring/ 3.3 grams in heel and middle and tip empty?
 
Yes exactly!
And this should work perfect according to heel clicker website.

But maybe something is worn out, binding or started to sag. Or it's just my setup that demands different settings.
Green secondary + 42-36 helix.
In the "screw-pac" I bought, the screws had the wrong thread.
I have found new ones and sorted out weights 1 & 2 gram and some 0,5 washers.
 
Hello again!
I would like to check the jetting now before the snow comes. So that I can finish the clutching and gearing early this winter.
At home I ride at sea level and it's usually around -10 celcius. When away we ride at approximately 3000 ft and usually also around -10 celcius. My pipes are Hauck/cpr and I can use either separate air filers or stock air box. (Meaning that I have both and not sure wich way to go. I think the box must be modded to work with the pipes. I really would like to use the box though for cold air and sound)

I searched the forum for info and I found different results.
So, I need good advise on the jetting. If I have to run different setups home/away I'll do that.
 
Ok.. Thanks. And carbs ventilated to it I guess.
Hope someone will chime in about the jets for that setup. :)
I have the separate filters on right now so imo with the air box I'll be jetted wrong as is.
 
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