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Discussion Starter #1
Hey everyone have a couple questions about the rear suspension on a 1996 Formula STX. I bought this sled last year and it's been nothing but headaches so far... I won't get into the engine issues, the guy before has it jetted... uh.. wrong? for a lack of a better term (430 on both PTO and MAG... actually the MAG jet wasn't even in, it was floating in the bowl...) and I think the oil injection is set way to high... long story short I'm taking it to a guy who's supposed to be "THE" sled mechanic in the area to get the engine issue's worked out.

So aside from the engine headaches, I decided to check out, grease and tune-up my sled before the season started. Was looking at the rear suspension and noticed a few things...

1) The spring supports are no longer round. The springs have worn about a cm or 2 down into the support. I'll just have to buy some new ones, is there anything I have to watch out for when removing or installing?

2) The springs are not straight. They are both bent in a bit of a wave type look... I thought this was normal but upon looking at the parts-list I noticed they are illustrated as being straight, and when I think about it, it would make ALOT more sense if they were straight. If these are wrong, what would cause this?

3) The rear suspension is quite soft... For instance, if you lift it up to it's maximum height where it stays, and then sit down, it sinks about 5 inches. If you sit down from where the suspension returns to, it drops about 3 inches. Now, I'm not sure where the stock 'ride height' is supposed to be, but it feels as though it's not returning it to a high enough position... Could this be caused by the spring supports and bent springs, or do I have a worn out shock too...

Any help is much appreciated!
-Thanks
 

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I had the same sled & found the suspention soft at 1st & found that it would stiffen up after a few mins of riding. Must have been the cheap shocks. It could also be old shocks if they have never been replaced. I have a 96 SLS & it has the same suspention & it does the same thing. I think the springs are rated for 220lbs max, so if you are close or heavier you might want to go with a heavier spring.
The supports are easy to change, just set it on the lowest setting, remove the bolt & replace the support. There will tension on the spring, not enough that you can't hold it.
There was one problem this suspention had. If you look at the upper wheels that are mounted on the same shaft as your springs, see if they have rubber on the outsite surface like the rest of the wheels. If it doesn't you will notice flat spots on them. This is because the snow melts down onto those wheels & freezes the wheel so it will not turn. There is updated wheels with rubber on them, you can get them from a dealer. Note this is an older sled so the dealer might have a problem looking them up. I had a problem with the dealer finding them for my SLS, but I told them to keep looking & they will find the update. They did & the parts were in stock. :thumbsup:
I bought a new 96 STX in 95 & rode it for 4 seasons. It was a great sled, only had one issue & that was the wheels freezing up. The suspention is good but it is no MXZ
If you need any more info, send me a PM & I will see what I can do. My 96 Formula SLS is the same but the chassis & motor, so I can compare things with that or with remembering when I owned my STX. :D My SLS has changed a little :whistling: because it is my watersled but I have all the stock parts.
 

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It is 12 model years old, what do you expect?
The suspention sucks for starters even if it were brand new.
The shocks are cheap motion control, junk from the factory.
You want a good ride get your wallet out and put about 5-700 bucks in it starting with a SC10ll with rebuildable shocks. Same rebuildable shocks up front.
 

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Discussion Starter #4
Thanks for the help so far...

I'm not complaining Mikadoo, I'm trying to get it up to top notch for this season so I can spend the season riding instead of fiddling.

Can anyone take a picture of the rear springs, or tell me how they are supposed to look? I'm not sure if they are supposed to be bent the way they are, or if they are supposed to be straight. (illustration on the fiche shows them as being straight) If all else fails I'll see if they have any in stock when I go and pick up the spring supports. I left the digital camera at the office but I can post a picture later, for now I'll quickly draw what it looks like:

Van Gogh original:

(woops, I meant spring support, spring slider works too haha)

Ski-doo Fiche:


Is the wave/bend normal? It's on both sides but I can't tell whether or not the bend is in the same place.
 

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Hehe, some have a bend some dont but either way its ok. You have to worry if the spring has a big "belly" which it does'nt by your VanGogh drawing.
I would guess the springs are off something else and one reason it sags so much.
I have a set of fatboy "square" springs in the basement for $20+shipping if you want them.
 

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Discussion Starter #7
Here is a pic of the suspention. From the side you can't see the bend in the spring. I will try to get a pic of the spring tomorrow[/b]
Thanks, that would be really helpful!
I fixed the engine problems myself, at least enough to get it starting on one pull and running for a few seconds without priming/throttle, it won't idle on it's own at the moment however... New plugs might fix that... I went through 5 sets of plugs getting this thing tuned up, so all 10 of my plugs are fouled in some way...

Well looked at those plastic idlers you mentioned and they both have flat spots, so another part to improve. Anything else I should look at... It appears as though the old owner didn't do any maintenance...

Ok now the last sled I did my own maintenance on was a 1980 polaris and I could move the track by hand when it was on a stand... Or say if i was moving it while it was not running, the track would turn as I pulled it.

I can't get this track to move a cm by hand!. Hell with it on a stand the engine was having a tough time turning it, is it that the tension is too tight? Or do I have more issues?
 

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Here is a couple of pics of the spring & you will see the bend. Check all your bearings, you might have one siezing up. If the sled was not maintained to good then I would pull the suspention out & go over the whole thing.
 

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