Xtra12 Adjustments - Snowmobile Forum: Your #1 Snowmobile Forum

XLT Spartan · 01-07-2009, 05:39 PM

Can anyone provide advice on what all the adjustments are and what each does on an Xtra 12 suspension on an 99 Touring? I need to make some adjustments, but this is the first time with this suspension.

wisconilaris · 01-07-2009, 07:22 PM

I found very valuable info on this subject right in my owners manual for my 96 xlt with x-tra 12. I imagine your is the same, and it's really very simple to understand once you read it.

Ultrafrozen · 01-07-2009, 07:30 PM

There are three adjustable support zones to the snow on a sled. 1) the skis, 2) the front of track and 3) the rear of track. Adjusting one zone stiffer will reduce the weight on one or two of the other zones.

If you have the same XTRA-12 as mine, the main adjustment is for rider weight affecting the rear of track. Unhook the rear suspension coil spring's front/ long end from the clip and adjust the block at the rear/ short end of the spring. Turn the block with the spark plug wrench to a higher position for heavier riders or stiffer rear suspension. This is much easier with the sled on its side. Don't forget to tighten the gas cap and oil tank cap if tipping. Too stiff here will give a bumpy ride and not allow full stroke or travel of the rear suspension. Too soft will allow rear to bottom out. Adjust so you bottom out slightly only on the biggest bumps.

The rear suspension has a front "coil-over-shock" spring preload adjustment. Compressing this spring more will stiffen the whole rear suspension and remove weight from the skis. When this zone is too stiff, the rear of the sled tends to fishtail more.

The rear suspension also has a non adjustable rear coil-over-shock. You can remove it to soften the rear suspension for really light drivers.

The ski suspension has adjustable preload on the left and right springs. Turn both adjusters equally to compress the springs giving more ski pressure on the snow and a higher and stiffer front end. When this zone is too stiff, steering effort is too hard (too hard to turn handle bars). When this zone is too soft, steering effect is lost (skis don't steer well, under-steer).

If you have the adjustable damping shocks, you can adjust the damping effect of the ski shocks and the front coil-over-shock. There are three turns on the screw with full out being the least dampened or softest, adjust half a turn at a time.

Let me know if you want info on the FRSS and limiter strap adjustment affecting weight transfer.

XLT Spartan · 01-07-2009, 09:29 PM

Quote:

Originally Posted by Ultrafrozen

There are three adjustable support zones to the snow on a sled. 1) the skis, 2) the front of track and 3) the rear of track. Adjusting one zone stiffer will reduce the weight on one or two of the other zones.

If you have the same XTRA-12 as mine, the main adjustment is for rider weight affecting the rear of track. Unhook the rear suspension coil spring's front/ long end from the clip and adjust the block at the rear/ short end of the spring. Turn the block with the spark plug wrench to a higher position for heavier riders or stiffer rear suspension. This is much easier with the sled on its side. Don't forget to tighten the gas cap and oil tank cap if tipping. Too stiff here will give a bumpy ride and not allow full stroke or travel of the rear suspension. Too soft will allow rear to bottom out. Adjust so you bottom out slightly only on the biggest bumps.

The rear suspension has a front "coil-over-shock" spring preload adjustment. Compressing this spring more will stiffen the whole rear suspension and remove weight from the skis. When this zone is too stiff, the rear of the sled tends to fishtail more.

The rear suspension also has a non adjustable rear coil-over-shock. You can remove it to soften the rear suspension for really light drivers.

The ski suspension has adjustable preload on the left and right springs. Turn both adjusters equally to compress the springs giving more ski pressure on the snow and a higher and stiffer front end. When this zone is too stiff, steering effort is too hard (too hard to turn handle bars). When this zone is too soft, steering effect is lost (skis don't steer well, under-steer).

If you have the adjustable damping shocks, you can adjust the damping effect of the ski shocks and the front coil-over-shock. There are three turns on the screw with full out being the least dampened or softest, adjust half a turn at a time.

Let me know if you want info on the FRSS and limiter strap adjustment affecting weight transfer.

Thanks UF! This is very helpful. I don't have a manual with the sled. Anything you can share about the FRSS and limiter strap would also be good.

CookieDoh · 02-07-2009, 12:12 PM

I have an xtra-12 and the front limiter straps have a lot of slack. I have more ski-pressure then I would like and some darting issues. The ski preload's are all the way loosened, I was going to loosen the limiter strap but it already seems all the way out. Any ideas?

Ultrafrozen · 02-07-2009, 05:30 PM

More preload on the rear skid's spring (coil over shock). This will remove some of the weight off the skis but also stiffen the rear suspension.

CookieDoh · 02-09-2009, 04:14 PM

Just to make sure, there are two shocks on the rear suspension but only the front appears adjustable? And more preload would be tightening and compressing the spring more right? Also, I noticed a screw on the bottom of my front ski shocks and I was wondering if it is just for bleeding/charging or if it is an adjustment.

XLT Spartan · 02-10-2009, 08:09 AM

What year is the sled? My rear shock (verticle) is adjustable by a screw. Turning that in stiffened the suspension a lot. The preload shock (horizontal) is a coil-over and can be compressed or losened by turning the large nut at the bottom. The shocks on the front ski's also have adjustment screws. Turning in will stiffen the front suspension. You have should have a total of 3 turns out from the bottom. Check the hood... there should be a weight chart there that also helped me dial-in my suspension.

JheLrey · 02-10-2009, 09:21 AM

Clean!!!!

Ultrafrozen · 02-10-2009, 11:53 AM

Quote:

Originally Posted by CookieDoh

Just to make sure, there are two shocks on the rear suspension but only the front appears adjustable? And more preload would be tightening and compressing the spring more right? Also, I noticed a screw on the bottom of my front ski shocks and I was wondering if it is just for bleeding/charging or if it is an adjustment.

Yes, front coil spring pre-load is adjustable, grab spring and turn, tighten for more. Two Rear spiral wound springs also adjustable but for rider weight.

The adjuster screw (adjustable compression damping) adjusts the compression rate of the shock and does not affect the spring preload. Higher compression damping rate will make suspension react slower (stiffer).

If you experience too much ski pressure during acceleration only, adjust the FRSS (front rear scissor stop).

Ultrafrozen · 02-10-2009, 01:49 PM

See pic:

Note: The Xtra 12 121" track suspension is slightly different than the Xtra 12 133.5" track suspension. 121" shown.

CookieDoh · 02-23-2009, 05:58 PM

Thanks for all the help. My darting trouble is lessened during acceleration. I bounce around a lot around 30mph, 40-50mph is much less shaky. The improvement on acceleration is part of why I was looking at ski pressure. I believe the improvement at higher speeds is because of the increased momentum makes it harder for the carbides to bite and pull the ski's around.

I'll check under the hood for rider weight chart info. And I'll check the PDF. thanks

soupkid · 02-23-2009, 07:44 PM

the darting thing can be a real PIA, thry checking you ski alignment should be 1/8" toe out.
Mine was a real hand full till I got around to checking the alignment was toed out almost 1" much better now

dustedwatts · 10-06-2010, 04:38 PM

Quote:

Originally Posted by Ultrafrozen

See pic:

Note: The Xtra 12 121" track suspension is slightly different than the Xtra 12 133.5" track suspension. 121" shown.

would you please check out this mod thread, you seam to know a ton about the xtra 12 thanks

this xtra 12 seams to be a good suspension, can not wait to ride it

http://www.snowmobileforum.com/polar...tml#post388414