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Discussion Starter #1
This past season was the first for me with this sled, 99 MXZ 670 HO.  It's quick but it handles like crap.  

The riding position is uncomfortable, it's difficult to post, but that's another story.

I'm looking for some feedback on set up to reduce the darting.

I'v got the front ski shocks preloaded heavily, the limiter strap is pulled two holes, the front shock is at position 2 and the the torsion spring is at position 2.

I just realigned the front end, set camber to 0 degrees, it was about 5, set the toe to zero

It's all stock, 144 studs and 8" carbide.

I weigh 170 lbs and ride aggressively.

Any comments?          Do they all dart like ####?

I don't like falling behind my Polaris buddies, I'm not used to that.

Thanks.
 

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Mine has some minor darting...but nothing major. I have the flex skis on mine. Inside ski lift is a problem with the S chassis, but you just have to learn when to move and you can correct that. If the darting really bothers you, maybe you should think about getting a set of SkiDoo precision skis or simmons skis with the dual carbides. They eliminate all darting.
 

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Discussion Starter #3
Thanks Rocketman, A ski swap may be a good option.

What's your opinion on the riding position?

I'm used to posting, it's tough on the S chassis.  It feels like the bars are too close and the boards too narrow.  

I've considered making my own riser that raises the bars about an inch and moves them forward 1.5 inches.  That coupled with some ROX treads was going to be my summer project.

Any comments?
 

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The running boards are definitely too narrow! and too flexible! The bars are too close to my knees, even with a 1" riser . I am a big guy though, so there is a reason the sled is too "small"
 

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HMMMM.... MXZ 670....I remember something about those...I think.

Darting - Your first problem is that you don't want all that weight on the skiis. The pre-load on the front shocks is to be set to keep the front end from bottoming. I bet it just beats the #### out of your arms, eh? You definitely don't want the limiter strap shortened unless you are drag racing. Weighing 170, you have the front rear shock set about right, but that the only thing that is right.

If you have snow left and want to try this, I think you will be pleasantly surprised. This is how I set an aggressive trail sled up:
1. The skiis should be toed out by 1/8" - 1/4" with a bunge cord hooking the ski loops together.
2. I prefer a 2 - 4 degree negative camber. It makes the sled dig more aggressively in the corners.
3. Let the limiter strap back out to stock length or one hole longer.
4. Set the pre-load on the front shocks to about 20% - 25% of total pre-load available.
5. Sharpen the carbides. (every ride)
6. Set the torsion springs so that you get about 2" - 2 1/2" of set when you set on the sled in snow. Don't set it in the garage on cement. It won't be the same.
7. Set the track tension to about 1 1/2 - 2 times the recommended deflection. If it ratchets, tighten the adjusters 1 flat at a time until it stops.

Now don't put any more pre-load on the fron shocks unless you bottom the belly a lot. Use the front rear shock to put weight on or take weight off the skiis.
I don't completely agree with Rocketman on the precision skiis. They do get rid of most darting, but they dart even worse than others when following another preci skiid sled. The flex ski that came on your sled is a good handling ski. On the camber adj, just remember that negative is more aggressive, positive is less aggressive. One more thing and I won't have you read any more. Ski lift... It's an SC-10...Get used to it and just ride it out. It won't tip over! A seriously great upgrade is the A.D. Boivin ETS system. I highly recommend it. It WILL take some time off the twistys and reel in those PooPoo's. (actually they should already be behind you once you get all this other stuff set up.)

Sorry to be so long winded, but I have spent considerable time on an SC-10 MXZ 670 and believe me, I didn't lag behind. This set-up will work.

Now I have a question for you. What the heck is posting? I haven't heard that term before.
 

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Yeah the flex skis aren't bad..the thing I notice though is that they throw alot of snow into your face. how are the precision skis for that?
 

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Yes, the ETS couplers are a must if you want to power out of the corners and run the front shocks as light as possible to stop most of the darting, with your light weight 0 would work good.
 

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Discussion Starter #9
Thanks Idooski,

It's funny, alot of your setup was already in place before I made the changes: negative camber, toe-out, limit strap,etc.

However, I'll give the whole set up a try as a system.  Unfortunately last weekend was the last for us.

The sled gets the most squirrelly as I slow for the turns, it's hard to set up for the right line.

BTW Posting is squating, motocross style to shift weight into the turns and absorb the bumps.  You probabaly have another name for it.

Thanks to all
 

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I have a 97 mxz 670 I set the front shocks at the softest pos.
In the rear skid front shock on #2 rear springs softest,  limiter strap in factory pos. acm? nut backed way only a few threads showing. I have c&a pro ski's, they work good all most to good some times. I weight 190lb.
 

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If it's real squirrelly when you get off the gas, you may want to check the front rear shock to be sure it still has pressure in it. It may be letting the skiis take all the decelleration instead of the shock helping. Or maybe just some more pre-load on the front rear and less on the front. But since the season is over for you, might as well check the shocks.
Thanks for the posting description. I guess I never really knew it had a name. I just hook my opposite toe in the well and let 'er all hang out!


mr670...I forgot about the ACM. I usually ran it tight if there were a lot of moguls, especially stutter bumps. Loose was fun, but it didn't ride as good.
 

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Discussion Starter #12
Thanks everyone,

Got plenty to consider.  

Shock recharge is a good idea, I'll bet they have never been touched.

Skeezer
 

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Set up the suspention like this.

Put the skis settings somewhere between half and low.  

On the center shock put it at 1 or 2 down from the highest setting.  

And set the rear for your weight according to the chart on the belt cover.

A set up like this will get rid of darting.  

If darting still happens up the center shock and tighten the skis by one.
 

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Doo you have the proactive controle system of bombardier, that little piece of plastic screwed under the skis? If not try it, stopped all darting on my sled and my bro's sled. It's about 30 $ canadian.
 
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