Fork swap - 1995 KX250

Questions and comments about converting to beefier forks..
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johnyblaze
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Fork swap - 1995 KX250

Post by johnyblaze »

The forks are in great shape, but I'd like to revalve them for woods/trail riding.

Can anyone tell me where to find a good shimstack for these 1995 KYBs?
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Re: Fork swap - 1995 KX250

Post by Julien D »

Been looking for the same info on my mid 90's KYB's. I assume my YZ forks are probably the same as your KX forks. I think removing half the largest shims from the stack will be a good starting point. I haven't gotten around to trying it yet.
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Fork swap - 1995 KX250

Post by Tedh98 »

Have you ridden the bike with the forks or did you just get the forks to begin the swap?
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Fork swap - 1995 KX250

Post by johnyblaze »

I just have the forks - never used them.

I've been perusing the web a lot and I found 2 pieces of info of interest. First, the 1995 YZ, KX and CR 43mm KYBs are the same. The second, from John IIRC at Moto-Pro suspensions says that the midvalve on the 95's is a checkplate only. And for woods/trail riding he recommended no changes to the midvalve or rebound on these forks. I didn't feel comfortable asking John about his suggested shimstack for this fork and this bike (cause he does that for $$$) but he did say that I would want .44 springs for my 200 pound (220 geared up). He said they're very good forks for a swap - the compression valve flows a lot of oil so no need for a goldvalve or ultramax. Just a revalve and shims are readily available.

From other sources on the net it seems that all that is necessary for a revalve on these forks for super plush woods riding is to remove enough of the largest shims 24x10 to leave only 3 of the biggest size instead of the stock MX of 10 larger shims. The rest of the base stack is great. Apparently getting those big shims out makes the 95's extremely responsive to clicker settings.

So, I'll only need to remove the base valve and remove shims/replace the base valves/remove caps/remove the .40 stock springs/replace with .44s replace the caps. Actually I have some .42s laying around so I'll probably try those before spending the $$$ for .44s.

I have the specs for the suggested stack (minus the larger shims) on another computer if anyones interested. Might come in handy if someone's been messing with the stacks already.
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Fork swap - 1995 KX250

Post by Tedh98 »

Sounds like you are off to a good start with that info. Removing some face shims is a common way to soften up a MX valved fork.

This what I have done and would do again when getting forks:
  • Pull the forks apart and at the very least put fresh oil in. Also check to see if the stems of the mid and base valves have the factory peening or staking. This would tell you if they have already been revalved or not. Also make sure the bushings are in good shape. No point in changing shims if the forks are in poor internal mechanical condition.
  • Ride the bike without making any shim changes. You need to get a baseline to work from. After riding, you might find the forks are nice and plush, but bottom too easily. Or they might deflect off of every little rock and root. Or they could be perfect.
  • Now make the shim changes and go out and test those changes.
Make sure to keep good notes of what you changed and the impact it has on the feel of the forks. There is a very good chance you won't get it right on the first revalve, so good notes will help steer you in the right direction.
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Re: Fork swap - 1995 KX250

Post by Julien D »

That seems to mesh with what I have found as well. I plan on doing this at some point. I actually have a set of 94 kx125 forks that should be about the same, which need a rebuild. I thought I'd do the work on those forks and then swap them out.
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Re: Fork swap - 1995 KX250

Post by johnyblaze »

Ya, I think the 94s and 95s are identical. Your 125s will have lighter springs than my 250's.
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Fork swap - 1995 KX250

Post by KDXGarage »

1994 does not have a midvalve and 1995 does.
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Fork swap - 1995 KX250

Post by Julien D »

Jason wrote:1994 does not have a midvalve and 1995 does.
Thanks, that's helpful! I can't recall, but I think my YZ250 forks are 93. I imagine they are about the same as my 94 kx forks. Haven't had the kx forks opened up yet so I'm not sure.
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Fork swap - 1995 KX250

Post by johnyblaze »

I ordered a 2004 cr250 SS braided brakeline. Hope it fits.
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Fork swap - 1995 KX250

Post by Kroynon »

Reviving this as I have done a 94 kx 250 fork swap onto my 92 KDX250.
Pulled the base valve today to see about softening things up a bit and found this.

18x.02x2
12x.005x2
14x.005
16x.005
18x.005
20x.005
16x.005
22x.005

with a 22x.02 on the other side.Clickers seem to have little effect.
Anyone know the stock stack for these forks?
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Re: Fork swap - 1995 KX250

Post by KDXGarage »

Is .005 in inches??

Was the top of the base valve already filed down?

Have any MX converters not tried pulling the smallest shim instead of the largest shim(s)??
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Re: Fork swap - 1995 KX250

Post by Kroynon »

.005 is inches
measured with dial calipers
the tops were filed down yes.
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Fork swap - 1995 KX250

Post by KDXGarage »

Thank you. I am used to metric on shims.

It does sound like someone has worked on them before. Do they look like the stock valves?

There used to be a website with stock valving kept in a database.

I looked on the Kawasaki website at the parts diagrams. It shows the base valve assembly as 1994 KX125 / KX250 only.

Get on Thumpertalk and earch through the suspension forums to see if someone ever posted the stock stacks there.

Here is all I could find about the stock 1995 KX250 fork valving I worked on for a buddy.

midvalve:

(3) 22.1
20.1
18.1

rebound:

21.1
21.1
17.1
20.1
18.1
16.1
14.1
12.2
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Re: Fork swap - 1995 KX250

Post by Kroynon »

Thanks,
I'll probably just put it back since it make no sense to me.
.005 is .127 mm so would that be a .15 then?
I've only seen .1 .15 .2
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Re: Fork swap - 1995 KX250

Post by KDXGarage »

Have you got a micrometer? I used to get consistent results from using a micrometer.

Look around on the internet for a suspension shim diagram chart from DaveJ. It is pretty handy. It has different diameter circles that you can use to figure out the diameters.

The shock has several .3mm shims on the compression side, if I am remembering correctly.

Since it just has a base valve and no midvalve, you won't have as many parts to worry about.

On your stack, is the 18 sitting on the valve, or is it at the top?
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Re: Fork swap - 1995 KX250

Post by Kroynon »

I almost forgot I had a micrometer set I havn't used it for a while but it measures .005 as well.
The two 18s are at the top, the 22 sits on the valve...
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Re: Fork swap - 1995 KX250

Post by KDXGarage »

Did it come off a bike set up for MX or woods? I am thinking that you may want to just try it and see.

Be sure to use the correct springs, weight oil and oil height.
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Re: Fork swap - 1995 KX250

Post by Kroynon »

Used forks I got from a MXer buddy.
He didn't know what had been done if anything. I rebuilt them and they work well except for sharp small hits. I use all but 1/2 inch of their travel in a normal ride. New oil and .42 springs. I'm I90lbs
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Re: Fork swap - 1995 KX250

Post by KDXGarage »

Well, good. You have narrowed it down. On to revalving.

More shims = more damping.

The larger the diameter of the shim, the more it will flex compared to the same force on a smaller diameter shim (think plastic school ruler hanging off the edge of the school desk).

Turning the clicker is more toward the bottoming out adjustment, so work with the shim to get it more to your liking.
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