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A Few RMK 900 Set-Up Questions

M

Mech Engr

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Sep 27, 2010
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I went on a nice long ride this Saturday and spent the day Sunday trying to get my 05 900 RMK set up for me. I have put about 100 miles on it since I bought it with 900 miles on it earlier in May. I’ve got the following questions:
1. I was trying to verify that the front shock dampening was set as soft as possible. I took the little sst button-head screw out but the adjuster screw seems to be stuck or seized. Is this common? What is the trick to get it un-seized so I can adjust?
2. I have always thought the rear of this sled sat a little low and when I pull up on the rear bumper the suspension allows it to come up 5 to 6”. I did the sag test and it sags the full specified amount with no rider. In other words I pull the rear bumper up all the way and take measurement X and then simply let go and it sags 5 to 6” without me jumping up and down on it as the manual says and then re-measuring. Now I know the manual says you may have to lift the rear slightly but this is way more than slightly and my wife’s sled you only have to lift and inch or so. I adjusted the torsion spring cams to the stiffest setting and no change. To me, it looks as if the rear shock should help hold the rear of the sled up. I have the Ryde FX ARVIN gas shock in the rear. Do these need to be recharged with nitrogen once in a while? This sled looks new and has very few miles on it so I find it hard to believe the torsion springs are worn out. If the shock needs a rebuild or service does anyone know a good place near Sacramento?
3. With regards to the optional altimeter and outside air temperature: I see that the plugs for these two options are present near the hood hinge right at the front of the sled and I also see that the instrument cluster is set up for them (I actually thought I had the altimeter when I was messing around with the display and all of a sudden the altimeter came up at 15,000 feet. Tried to adjust and it wouldn’t go below 12,700 feet…well duh no sensor in the plug!!). Is it just as simple as buying the two sensors and plugging them in for a working altimeter and outside air temp?

Thanks for any input.

Big John
 

guidoxpress

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1. no expierence with the shocks, but i know they are very hard to screw in and out..

2. sounds like your torsion springs are sacked out. you should replace them with theses ones.

7042079-067 Spring, Torsion, LH, STD [.375/47 °]
7042080-067 Spring, Torsion, RH, STD [.375/47 °]

here is a great thread on this.

http://www.snowestonline.com/forum/showthread.php?t=165462

3. yep the sensors are just plug and play ;)
 

Z-Man

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Rear torsion springs are extremely soft on these sleds. I weigh around 200 and unless they were set to stiffest setting the rear was way down and the skis barely touched the ground and you had terrible steering control.

If they are still to soft on the highest setting you need to replace them, or do what I did, change the suspension.:face-icon-small-win
 

94fordguy

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Rear torsion springs are extremely soft on these sleds. I weigh around 200 and unless they were set to stiffest setting the rear was way down and the skis barely touched the ground and you had terrible steering control.

If they are still to soft on the highest setting you need to replace them, or do what I did, change the suspension.:face-icon-small-win

Ya, that^^^^^^^



My buddy changed his out this summer form the same sag amounts you have... funny to see his sled look like it ISN'T a low rider anymore, LOL

Mine are beggining to get a little weak, but not near that bad...


The sensors are plug and play, make sure to put the temp sensor near the front bumper so it can get FRESH cold air for maximum accuracy and the Altimeter is a glorified Barometric sensor... it can be off by about 2-300 ft depending on high or low pressure weather systems, but it is nice for a rough guess of how high you are.
 

mountainhorse

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John,

1. I was trying to verify that the front shock dampening was set as soft as possible. I took the little sst button-head screw out but the adjuster screw seems to be stuck or seized. Is this common? What is the trick to get it un-seized so I can adjust?

What brand/model shocks are you talking about?

I have the Ryde FX ARVIN gas shock in the rear. Do these need to be recharged with nitrogen once in a while?

There are two different kinds of Ryde-FX shocks... the Black colored MPV shocks and the Aluminum bodied rebuildables.

Photos are helpfull when asking for help.

IMO, All the 900's with stock rear suspension should have the 225 lb front track spring installed and the 47 degree rear torsion springs... with the .359 or .375" size dependent on your weight.
 
M

Mech Engr

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The front shocks are the stock Ryde FX that come stock with the sled and are shown in the manual. The rear is also a Ryde FK (definately not black) with an anodized aluminum compression dampning adjustment knob. This shock is also shown in the 2005 deep snow manual page 50 and is called the ARVIN rapid adjust shock. In the manual, both front and rear shocks that I have are identified as "premium."

The torsions springs are a little pricey at $64 each. If I'm going to pay that much I'd like to get some that don't go bad after a measily 900 miles! I bought it from the original owner and he was maybe 130 pounds soaking wet! Do they make any higher quality aftermarket springs?

Thanks for all the replys!!
 

Z-Man

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The front shocks are the stock Ryde FX that come stock with the sled and are shown in the manual. The rear is also a Ryde FK (definately not black) with an anodized aluminum compression dampning adjustment knob. This shock is also shown in the 2005 deep snow manual page 50 and is called the ARVIN rapid adjust shock. In the manual, both front and rear shocks that I have are identified as "premium."

The torsions springs are a little pricey at $64 each. If I'm going to pay that much I'd like to get some that don't go bad after a measily 900 miles! I bought it from the original owner and he was maybe 130 pounds soaking wet! Do they make any higher quality aftermarket springs?

Thanks for all the replys!!

They make titanium springs if you want to spend the money on them. Lighter and stronger.
 

Z-Man

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Looks like the superceeded the original part number to a new design on the springs too. If the original owner was only 130 lbs the sled was probably set up with lighter springs, so the problem is not that they are worn out but they are the wrong ones for your weight. I see three different ones listed.
 

mountainhorse

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1. I was trying to verify that the front shock dampening was set as soft as possible. I took the little sst button-head screw out but the adjuster screw seems to be stuck or seized. Is this common? What is the trick to get it un-seized so I can adjust?

That is not an adjustment... It is a nitrogen fill port. Do not unscrew that as it is under high pressure.

These shocks are designed to be rebuilt... or serviced... Oil and nitrogen and seals if needed every 1500 miles or so depending on conditions.

Get them serviced and get the new spring on the front track shock (aka center-shock) and on the rear torsion springs.

The Ti springs are too expensive in my book and unless you have dropped a lot of toher weight already, dont really make sense in my Opinion.

Good luck.
 
M

Mech Engr

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The correct torsion spring numbers for the .375" springs are:

7041942 and 7041943

The 7042079 and 7042080 are NOT for the 900 RMK (or there must be some modification in order to use them). They are listed as .375" but the open angle is 47 degree rather than the 77 degree needed for the 900 RMK.

John
 
C

chunkysoup

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I put the 47 degree .375 springs on my 900 with no modifications. the reason for running that spring is that it will be "preloaded" with the extra 30 degrees. U will essentially have no sag. I would recommend the 47 degree springs, look and ride very nice.
 
Last edited:
M

Mech Engr

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Sep 27, 2010
246
123
43
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900

I put the 47 degree .375 springs on my 900 with no modifications. the reason for running that spring is that it will be "preloaded" with the extra 30 degrees. U will essentially have no sag. I would recommend the 47 degree springs, look and ride very nice.

Thanks!! I figured there was some trick.

John
 
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BIGGDAWG

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Do the .405 torsion springs come in a 47 degree angle, if not would the .375 with the 47 degree angle be better than the .405 with the 77 degree angle? I am about 270 all geared up.


i will tell ya the 405's are stiff, on the lightest setting they are as stiff or stiffer than the .375/77 on its stiffest setting. at least that is how it road. switch to the .375's after that but i am 200 just some info
 

guidoxpress

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does anyone know if the .405/47 will fit my 05 900rmk without modifications?

No Issues or mods required, they will bolt right on, however. The .405 are usually heavier then what's needed and I believe are slightly wider and can run the wheel..

I would highly encourage you use the .375/47 unless you got a smoking deal on the 405 already

The springs are a HUGE improvement and also do the 5/8" rear torque arm mod while your doing it, you will thank me later trust me
 
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