Compression valve

16 replies to this topic
  • etuke

Posted April 25, 2013 - 03:09 PM


While changing my fork seals I notice the nut on the compression valve was slack so I decided to tighten it and it snapped.I don't see this part available separately,seems now I have to buy the whole compression valve assy.I'm soo pissed right now,was planning on using it this weekend now I'm gona have to order parts that's probably gona cost me $300.If there is another solution I'm all ears but I don't expect there to be.Don't even see used items available on ebay.

  • asnyder2

Posted April 25, 2013 - 04:56 PM


If they are twin chamber, you can buy the stem from sdi for about 23.00 plus another dollar or two for the nut. I had one break on mine when torqued to spec per spi build ( probably 5th or 6th time apart though).

  • etuke

Posted April 25, 2013 - 06:24 PM


Yeah they have them just the shipping is the same as the part and that's just ground,I wanted to get it as fast as possible and then the shipping goes to over $100.When the holder snapped the valve stack came loose and now I'm not sure how to put them back together.I could take apart the other but I just got that 1 together with new seals and oil.I thought about tapping the inside of the holder and installing a small bolt to hold the valve but then I notice it has a hole all the way through.I'm assuming its for the compression adjuster and If I cap it with a bolt it will lock up.Will check the local yamaha dealer tomorrow but I doubt they will have this in stock,looks like another weekend without riding,hope it rains. :banghead: I'm so pissed!!!

there is a small amount of threads left on the holder,what if I took off some of the valve stack to get the nut on,would it be usable until I get a new part?

  • asnyder2

Posted April 25, 2013 - 07:28 PM


I wouldnt risk it. Could cause alot more dmg uf there is a failure.There is no way around it. If I were u, id order 2 just have another.

  • asnyder2

Posted April 25, 2013 - 07:34 PM


Besides, imagine if that nut came iff and all the pieces fell down into the midvalve and beats the cartridge/pistons/shims to a worthless pile of crap. Talk about pissed! (Not speaking from experience but hypothetical situation that trying to cheat a $20 part could cost u hundreds)

  • grayracer513

Posted April 25, 2013 - 08:09 PM


SMART Performance or Suspension Direct will have the part you need. They're only about $25. Most places here would call that the "base valve stem", or "compression valve stem". Should be right around $25.

  • etuke

Posted April 26, 2013 - 11:39 AM


Have 2 stems and 2 nuts ordered from smart performance,thier shipping was a lot more reasonable and part was a tad cheaper.The whole assy from Yamaha was $329 but got the 2 parts for $78 incl shipping.Only thing is when it arrives I have to figure out the shim stack or if anybody is familiar with how the shims align I would appreciate the info.From what I could tell it looked like the main valve with a load of shims that laid up against an aluminum washer with a few more shims(large to small)that went up against the base of the compression stem.If you have any info on how its supposed to be I would appreciate it.

  • asnyder2

Posted April 26, 2013 - 12:08 PM


Your best bet is to disassemble other side to ensure that they will be the same. One shim out of place can make a difference.

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  • grayracer513

Posted April 26, 2013 - 12:44 PM


Here's what the stock '08 compression stack looks like:

32 x 11(x18)
30 x 11
28 x 11
26 x 11
24 x 11
22 x 11
20 x 11
18 x 15
17 x 25

If yours is different, post back. On the opposite side from the valve stack is a check plate. This will look like the other 32's but should have a larger center hole. There is also a light spring, a slide collar, and a cup washer, then a small steel washer and a nut.

  • etuke

Posted April 26, 2013 - 01:19 PM


from the nut to the back of the main valve assy didn't move so I know they are right,were it gets unknown to me is the small washer(I thought it was aluminum) and the shims associated with that.I'm not sure if the fibre shims go against the valve stem or against the other fibre shims then the metal washer up against the base of the valve stem.It really just the orientation of the small metal washer and the 3 or 4 shims that went with it.I could pull apart the other side but would rather not.I have it all put back together now as to not loose any pieces just waiting for the new parts then will pull it apart and take pics if necessary.

  • etuke

Posted April 26, 2013 - 01:32 PM


Item 7 at the top is the area where I'm lost but if this pic is correct then it clears it up,the washer in the middle then the shims to the base of the stem.the bigger main stack didn't come apart just where the metal(middle) washer separated when if fell off and wasn't sure what direction it went back.All the shims stayed together.

Attached Thumbnails

  • comp_adj_assy.jpg

Edited by etuke, April 26, 2013 - 01:33 PM.

  • grayracer513

Posted April 26, 2013 - 01:51 PM


There are no fiber shims involved. See if this helps:

Attached Thumbnails

  • base.jpg

  • etuke

Posted April 26, 2013 - 03:26 PM


your pic doesn't show shims past the washer towards the left but my bike had shims in that area,at least that's where I thought they came from.The thing is the bigger shim pack tapers out to a small shim at the end then mine had another 3 or 4 shims that started bigger than the last of the main shims and tapered down again exactly like the pic I gave.My pic has d which is the stem then the first part of 7 which are shims then the washer then the main shims(that's how I saw mine).In your pic there isn't any shims past the washer by the stem so it doesn't look like what I have but the rest looks right.Maybe mine has been pulled apart before and mixed up,if there is supposed to be only shims on the piston then mine was wrong but by the pic I gave it looks right.This is my first time into these type of forks and I had no plans on getting into the shims but fate has put me here now and I have to deal with it even if I have to pull the other side apart again.Appreciate all the help and hopefully will get this figured out without pulling the other side.I called the shims fibre but they may never be,the 1's I refer to are the non metallic shims.

  • grayracer513

Posted April 26, 2013 - 03:51 PM


Sounds like someone tried to add a bleed stack. If that's the case, you should pull the other compression assembly and lay it out. The YZ450 never had one. Either that, or someone may have reduced the compression stack and stored the removed shims under the base washer as a way of keeping the total stack height big enough. If it gets too short, the nut can't tighten down on it.

Regardless, it's not a stock stack if that's how it was, and if you have no record of the configuration, you're going to have to match it up with the other one.

  • etuke

Posted April 26, 2013 - 04:16 PM


the stem end was peened so it was either factory or somebody peened the end again but it looked factory to me.Either way will this cause trouble?I'm not a racer just a weekend rider and a softer fork is more appealing to me if that's what it does.Are the shims supposed to be loose or does the nut tighten them all down to the piston?I have a feeling that the other side is going to show the same orientation of shims so if its not factory I may not have anything to go by to make it factory.

Edited by etuke, April 26, 2013 - 04:18 PM.

  • grayracer513

Posted April 26, 2013 - 05:55 PM


I gave you the stock stack, so you could "make it factory" if you want, but it should at least come close to matching up with the other side, too.

And yes, the stacl has to be clamped down tight, or it will not work like it's supposed to, and will likely beat itself apart.

  • etuke

Posted April 26, 2013 - 06:14 PM


I gave you the stock stack, so you could "make it factory" if you want, but it should at least come close to matching up with the other side, too.

And yes, the stacl has to be clamped down tight, or it will not work like it's supposed to, and will likely beat itself apart.

Guess when I get the stems I will be pulling apart the 2,thanks for the help.

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