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Discussion Starter · #1 ·
Hello all.
I've been putting this sled back together for a while. It was a basket case when I got it. Now that I have things back in order and ready for a test run I find that the skid frame is very soft. I have put on a new rear shock and springs and there was little to no change. There is nothing binding. I sit on the machine (I'm 240 lbs) and it dam near bottoms out.
Any ideas as to what is going on?
Thanks
 

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I am about 215lbs and I find my 97 to be a tad stiff for normal trail cruising..Even with the springs on the lightest settings..Are you sure you have the correct springs?If so you may have to look into some two up grand touring type springs.
 

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Discussion Starter · #7 ·
Right springs. Wish I had your problem chilly. I lift the back end up. Let go and it drops six inches and that with no seat. Get on it and snow flap hits the ground. Going to change front shock but I have my doughts it's going to change anything but it's the only think i haven't changed. No one has changed the mounting. Is it possible this 97 had a different skid under it from factory? Bolt to bolt c to c is 24 5/8
Thanks for response
 

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Discussion Starter · #8 ·
Ok. I now have changed the front shock and no change to this soft skid frame. So all is new and all moves freely and still it hits the ground with little effort. All are the right parts. Springs on max and a baby could bottom it out. What gives????
 

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Do you have SC-10 or ??

Interesting reading I found about your problem

from http://www.ski-doo.com/Archives/english/archives_1998/98models/a_lab_03.html

SC-10 REAR SUSPENSIONS (Super Comfort 10" of travel)
Most Ski-Doo rear suspensions are created from this long-travel platform. Shocks, springs and other mechanicals are calibrated for comfort and performance in all types of riding.

Rising-Rate SC-10: High Performance, Cross Country variations
Used in performance applications, this version of the SC-10 provides the most absorption at the end of its travel, for optimum cushioning. It is also calibrated to sag about one-third of its travel length to provide a lower center of gravity in normal riding conditions. When it encounters a big bump, it expands, then uses all 10 inches to cushion the bump.

Falling-Rate SC-10: Sport, Touring and Mountain variations
Using geometry and components calibrated and designed to provide the most absorption at the beginning of its travel, this suspension cushions the moderate bumps in trail riding best.

ACM (Acceleration and Control Modulator)
The patented ACM on the SC-10 rising-rate rear suspension connects the actions of the rear arm to the front arm. It allows the suspension to absorb big bumps better by distributing the impact between both rear shocks and suspension arms. Riders can adjust the sled's mix of acceleration (ski lift) and cornering bite (ski-pressure) by turning a nut on the ACM. When adjusted for cornering, it causes the sled to sit flatter during acceleration, increasing ski pressure and control.

ARC Rear Suspension
New for 1998 and used exclusively on the Formula Z 670 model, the ARC is a fully-coupled rear suspension and is designed especially for aggressive trail riding. It uses one swingarm with two shocks mounted at the center of the suspension. Two control arms transmit bump energy from the front to the back and fice versa. This coupling action also controls weight transfer to improve handling qualities like balance and ski bite.

SC-10 High Performance LT with Pneumatic Leveler
Standard on the Grand Touring SE model, this driver-controlled suspension system uses pressurized air in the rear shock of the SC-10 High Performance LT to absorb the bumps. The driver can achieve the smoothest ride possible for conditions--soft or hard surfaces and varying driver, passenger and luggage weights--by increasing or decreasing the air pressure in the shock with the on-board air compressor at the flick of a console switch.

Direct Shock Action (DSA) Front Suspension

DSA is a trailing arm front suspension that comes in several variations and travel lengths depending on the application and shock choice. New for '98 on all CK3 machines is an unequal length radius rod configuration. Radius rods control the trailing arms' lateral movement during suspension action. The unequal length set-up flattens the travel arc for more precise ski camber and toe-in during suspension action, which makes for precise steering.
 

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Discussion Starter · #12 ·
Yes it's a sc-10. Shocks and springs bought from royal (kimpex?). There was no change when installed. Seems like there is no up lift. Goes down and stays down with little left for suspention. Front shock replaced but did not replace coil. Great read. Maybe acm is the issue and needs to be adjusted? Checked my neighbours sled. Same sled and I know it needs shock and springs and it have more up lift than mine. Not sure what to make of it but it can't be ridden the way it is.
 

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Hate to tell you but those kimpex shocks and springs are junk brand new. I found out the hard way also. Replaced everything and it wasn't any better than before. Gonna have to get some doo springs and try to find a hpg shock, I'd get some 2up springs also for your size.

Good luck.
 

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if you are able to, take a picture of the mounts for the springs. The plastic triangle shaped piece that the spring slides through. This is mounted to the skid frame with a single bolt. Most of these I have encountered with any mileage on them at all are almost always bent because they use too small of a bolt. I have drilled out the skid frame and replaced them with a larger bolt to add strength to them. More importantly, check to make sure that yours are installed correctly. They should be installed so that the part that the spring slides in is ABOVE the mounting bolt. if it is below the mounting bolt, it will remove a great deal of the preload from the rear springs and also cause a very dangerous situation in which they could let loose and go right through your track (seen it happen before). If these have been replaced or altered in the past, either by yourself or the previous owner, it would not surprise me if they had been installed incorrectly. They are quite difficult to compress to get them above the mounting hole to put the bolt in them, but they go on relatively easy if you incorrectly mount them below the mounting hole.
 

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Discussion Starter · #15 ·
The spring is above bolt in trangle piece. Good to know that its a weak spot in the system. Kimpex is crap? Never heard that befor. Still thinking its the acm some how. Havent had time to see if i can ajust that some how and make a difference.
Thanks for the responces.
 

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Discussion Starter · #16 ·
So with some twiking this is what i have. I pull up on back end to 19 inches from floor to top of tunnel. Let go and it rest at 16 inches. Sit on it and it goes to 14 inches with some spring left. Does this sound right???
 

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That's quite a bit of sag, but it'll work. I think your problem still lies in the Kimpex torsion springs, the ones I bought for mine were junk brand new. I ended up going to a dealer and getting Doo springs and my problem was solved. The Kimpex shock isn't complete junk, but it will be in less than a 1000 miles and no way to rebuild it. Just my opinion mind you. :biggrin_old:
 

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. Kimpex is crap? Never heard that befor.
really? im very surprised pretty much everything from kimpex is garbage .i think your problem is your front shock spring is no good i say this because few years ago my front shock mount broke and i thought i could drive the sled for a short ride with only the rear springs and the sled did exactly what your saying i only weight 150 and it would slam to the ground sitting on it now you being heavier plus the front spring is still doing something i think your front spring is no good. did you have to compress the spring it get the shockon/installed ? a good inch or two? when i did mine i had to use ratchet straps to compress it to get the shock in and the clip on
 

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that cat in my sig pic has a sc-10 in it from my mxz and when two people sit on it it dont go down near as much as you say maybe 4 inches
 

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So with some twiking this is what i have. I pull up on back end to 19 inches from floor to top of tunnel. Let go and it rest at 16 inches. Sit on it and it goes to 14 inches with some spring left. Does this sound right???
You need heavier torsion springs. They are rated for about a 200 lb rider from the factory. Your total sag should be about 2in just the sled, and about 3 to 4 in with the rider. Your current total is 5in, thus the need for heavier springs. The front shock spring does little for ride height, it is for adjusting ride firmness and ski pressure. I have the doo part numbers for the firmer springs if I get a chance tonight I will find them.

Sent from my ADR6425LVW using Tapatalk
 
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