KDXRIDER.NET

finally got the shock out of my kdx220sr and pulled it apart, could see that it had been rebuilt before so contacted the previous owner and he confirmed he had rebuilt it using all balls seal head kit and bel ray 3wt shock oil. checked the shim stack against specs that were on previous threads and its the same so nothing different about the rear shock for the SR model. as in my previous post i stated that the shock is terribly harsh for my 60kg frame even with the yz125 spring. i searched everywhere in town and shock oil doesn't exist here so motul fork oil 2.5w is my only option, i did a simple viscosity check against the bel ray that was in it and it was 24 seconds belray and 22 seconds motul 2.5w , roughly a 10 percent difference and i feel not enough to make a real difference on the harshness so modifying the shim stack is the only option. only thread i could find on softening the stack is in this thread viewtopic.php?t=13217
my plan is to do something similar but remove 2 or 3 of the 38 shims and sand down the 19 clamp shim to a 17.
also the valve body in the photo. is it the right way around?
kind of just looking for confirmation that i am doing the right thing before i put it back together

I Recently removed one 38mm shim from the comp initial stage and did not notice much difference so you may want to go more. Reducing the diameter on the last comp shim in theory should help speed up the rest of the range, though it may not be enough. On another recent shock revalve (rebound only) I opted to go with an additional smaller base shim with twice the thickness to speed up the mid-final stage.

Where are you feeling the harshness? are you sure its not in the rebound?

Suggestions:

Remove 2 38's, then the 32 and 28

Surface the piston.



Skip sanding shims.

The shims that were on the faces of the piston usually have marks of where the piston ports rubbed against them. The bigger side is compression. The smaller side is rebound.

If you have not alreay watched the Race Tech videos from 1993, watch them over and over until it makes sense. I did. They helped me trememndously when I first started trying to learn about what to do.

good video. will watch it a few times. only yesterday i had no idea how shims worked and today i do :)
came across this shim stack info from the earlier model kdx and from what i know they were softer than the H series
Compression (piston face outwards)
38.2 x 6
23.1
38.25
36.25
34.2
30.25
28.25
26.25
24.25
20.25

REBOUND (piston face outwards)
34.2 x 5
23.1
34.25
30.25
28.25
26.25
24.25
22.25
26.25
26.15
24.25
24.25
24.1

I would NOT go by some other model shock. That "other model" shock could be bolted to a different:

linkage system of angles
swingarm
frame mounts for swingarm
swingarm length
frame mount for top of shock
etc.

Be aware if too many shims are removed the overall stack height might not be within tolerance. Spacer shims will be needed so the retainer (top) nut sits correctly without bottoming on the tread end where it meets the shaft step. In other words the overall stack/ piston/ washer dimension must be the same as the original stack.

OK, the ones I said to take off, put them under the bottom most shim. Easy Peasy Japaneasy.