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Ok, before anyone says read thru all the old posts, let me say that I did and didn't really find what I was looking for... I am sure the=is has been covered forty eight billion times but what I need is all the basic knowledge of the clutch-I am not affraid to rip something apart and fabricate when its necessary. I have ripped apart and tuned enough cars, but I am new to the tunin the sled!!

I am fairly light- 165 lbs with a 99 Mach Z with V-force Reeds, PSI pipes, cans and a track with 192 studs. I ride mostly packed trail with an occasional romp in the powder or a run across the lake.

What I am wondering is I tried to put a Goodwin clutch kit. The primary I thought was pretty straight foward since it was just takin out the old ramps and spring and putting the other ones in. Did I miss something here or was that correct in assuming? I keep seeing all this stuff about weights and such. It came with a blue spring for the primary if that helps.

I did the secondary and this is where I think I screwed it up. I put the new spring in the holes that the stock one came out of thinkin this was a good place to start.

This is what the sled did when I finally pulled it out of the shop- It will tool around the yard fine which is what I started with to make sure it wasn't goin to self-destruct. When I romp on the gas the RPM's jump right up to right around 8600 but as soon as the sled starts to pull the RPM's drop right down to 5500 and it won't go any higher. After I back off the throttle and slow down, it will do the same thing once I hop on the gas.

Now I know a lot of you are prolly sayin "What a moron..its clearly his ...." and thats fine. I am just lookin for some good ol' help here broken down to Barney level. I mean talk to me as though I am smart, but I need the basics of how the clutch and shifting works.

Please guys, I know I am a moron about clutches still, but I willin to learn and listen!!
 

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You have a secondary clutch which requires side tension meaning when you start to bring the cam down to install the snap ring you have to turn the sheves to "wind" the spring up. Once you do this you "should" have around 16lbs of twist on the clutch this can be measured wtih an ice fishing scale. Take teh clutch and hook the cluch in one of the balance holes around the sheve and have someone hold the clutch on the bottom sheve. Pull on it with the scale and see how many lbs it takes to move it then slowly release it and see what lbs it releases at add those #s togeather and then divide by 2 to get the tension. Shoot for around 16lbs.

Hope that helps seems clear as mudd.
 

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I hear you, a little basic clutch set up would be greatly appreciated. I can tear mine apart, clean and get them back together, and adjust a little, but it's knowing what you're doing that would be usefull.

What I can share with you is it is good to have good clutch tools. They aren't too expensive from skidoo, but if you have ever seen them (spring compressor and puck retainers) they're really easy to make your own, and they make working on them much easier.

I think what the other post meant by the pre wrap tension may be what you missed and why yours is running so funny. When you are putting the secondary back together you dont push the helix straight in, you have to preload it, basically twist it back one ramp. You have to adjust the spring location to get the prelaod tension right. Stock is somewhere around 18 lbs?, but changes with different set ups. This tension is the force it takes to rotate the inner sheave when the outer is held still. I've tried to make a jig so I can measure it with a torque wrench, but I've heard of guys using fish scales. This part though, I'm not sure how to properly do it. If you give your clutch a twist and feel the tension before and after tearing it apart, you'll at least know if you're in the ball park. Try to feel the tension on yours by hand, It should take some muscle to twist, and that may tell you if you got it back together right.

In the primary, you can change the ramps and the spring, and the clickers adjust the height of the ramps. But then there are also the arms, the rollers on the end of the arms, and the pins that hold rollers. I'm not sure if 'weights' refers to the rollers, pins or both. But all of these will affect the way the clutch shifts.

Sorry for being so long winded. Hopefully now people will correct my mistakes and elaborate so we can all figgure it out better.

I'd really like to know how to properly set the secondary tension, mine is all stock, so that I can be sure I've got it tuned right.
 

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TheGhost said:
You have a secondary clutch which requires side tension meaning when you start to bring the cam down to install the snap ring you have to turn the sheves to "wind" the spring up. Once you do this you "should" have around 16lbs of twist on the clutch this can be measured wtih an ice fishing scale. Take teh clutch and hook the cluch in one of the balance holes around the sheve and have someone hold the clutch on the bottom sheve. Pull on it with the scale and see how many lbs it takes to move it then slowly release it and see what lbs it releases at add those #s togeather and then divide by 2 to get the tension. Shoot for around 16lbs.

Hope that helps seems clear as mudd.
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No one ever told me to average it like that before, I'll give it a try. Perfect timing too, because I just cleaned my clutch and it's on the bench right now. My problem is you can rotate the sheaves about 1/5th of a turn, and the pulling tension is greater at the end of the 1/5th than it is at the start. Do we want to measure the initial pull, or the heaviest pull?

uggg..... more mud.
 

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So we measure the pull force at the start, and the force at which it starts to return, and take the average. For stock set up, we want about 16Lbs? Is this the correct tension?
Also, does anybody know what the sweet spot WOT RPM is that we should be shooting for on a '95 mach 1 670?
I get all giddy when I'm learning!
 

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I just pull it thru the break point and read it at that point, it will read hi to break the friction but when you have moved it a little you will find a consistant number. The exact number of lbs will vary with weight of rider, snow condition, how crisp you have the jetting,on +on+on. It helps to have some way of verifing results, buddys sled left alone between trials or a set of clocks, stop watch.
 

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DougB said:
I just pull it thru the break point and read it at that point, it will read hi to break the friction but when you have moved it a little you will find a consistant number. The exact number of lbs will vary with weight of rider, snow condition, how crisp you have the jetting,on +on+on. It helps to have some way of verifing results, buddys sled left alone between trials or a set of clocks, stop watch.
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So what is it that should be affected by changing the secondary tension? Accelleration, top end, rpm, shifting? Basically what should I be trying to accomplish by adjusting the tension, as in how do you know when it is dialed in.
 

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The tension on the secondary is one of the factors in determening your upshift and back shift. It senses load at the track and trys to shift up. The primary trys to keep the motor on the powerband, it would take 10 pages here to cover just the basics, if realy interested aaen has a very good book on clutching. Also go to revzone a sponser on here and find FAQ about clutching, there is a very good section on gearing there also.
 

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Yeah, local dealer said Doo spec was 16lbs. I also read that looser, while better for drag racing, leads to more belt slipping, clutch heating and belt wear. Tighter is cooler, likely easier on the belts, and better in deeper snow.
They also said peak RPM for twin pipe 670 should be 8200-8250. I think I'm only doing 7800-7900. I'm going to check the tension on the secondary, and try about 17 lbs for trail riding. Then I guess I'll raise the clicker number to get me to 8200 RPM.
 

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Discussion Starter · #13 ·
I did give the helix the turn on the ramps, but maybe it slipped out right at the last minute. I was doin it by myself and with a a pretty 'ghetto' clutch compressor. I am takin the clutch to my local shop to see if he can figure it out.

Thanks for all the replies- it does help things out quite a bit...

My only other question is I hear people talkin about adjusting the primary by 'clicks' to adjust max RPM. I am not quite sure what they mean...I know this is basic to other people but I would like to learn how to adjust the clutches to get the best performance possible...

Reminder- the sled does have PSI pipes and cans, anyone know off hand what RPM they are meant for?? I picked them up used for a good price, but he didn't inform what RPM they are meant for-
 

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I'd love to have a shop manual for the sled. Right now all I have is a printed off microfiche and parts list. Any good manuals to recommend?

About the clicker's, its the 3 bolts on the outside of the primary. If you look there are numbers around the bolt head. The shaft of the bolt is actually a cam lobe, and as you turn it, it raises or lowers the top of the ramps, and affects the top RPM.

Hopefully this picture works and you can see the bolt head with teh numbers, and the nut you have to loosen to adjust it.
Also check this forum, the two pinned threads should give you a lot of info on clutch disassembly.

http://www.snowmobileworld.com/forum/index.php?showforum=64
 

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Hey guys, you need a tech cd. It's got shop manuals, parts books, race books, all the goodies, check with your dealer he might have one for your earlier model sleds. There are also pirated copies on Ebay all the time. Current model sleds usually have to wait a year for them...
 

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No torque spec. But when you try to move the "clickers" DO NOT take the nuts all the way off, just back them off far enough to back the head out far enough to turn, ALLWAYS recheck all three are on same number. The nuts just need to be firm, this is an alum. casting spinning 80000 dont distort it. My earlier post had a miss speak in it, I said it trys to upshift when it is allways trying to backshift but I think you are getting some real good "barney level" tips here from all the guys. Get a little note book and keep notes as you try things, include temperature when you test it will help because a few degrees dif. can make a diferance. I need spell check.
 

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The clutch bolt spec reads:

Drive pulley retaining screw: torque to 90 to 100 N•m (66 to 74 lbf•ft),
install drive belt, accelerate the vehicle at low speed (maximum 30 km/h
(20 MPH)) and apply the brake; repeat 5 times. Recheck the torque of
90 to 100 N•m (66 to 74 lbf•ft).
 
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