2000 kx500 base valve shim stacks

[TopperHarley]

After reading a plethera of posts about revalving the stock KX base valves, I decided to disassemble mine and see how they were stacked. I was under the assumption that they were factory stacked and had not been re-stacked. I was expecting to find a series of 12 large (24 or 22mm) shims and my intention was to remove some of them. I read a couple posts which suggested removing all but 4 of the large ones. To my suprise there were only 4 lg ones in the stack. This is how they were stacked from below the valve:

4x22mm
1x20mm
1x18mm
1x16mm
1x14mm
1x11mm clamp shim
2x18mm backer shims

I am assuming that they were revalved at some point. Anybody farmiliar with a stacks like these? the first nine are like .003in thick. the last two are like thick as nickels...well, not that thick. 6 times the thickness of the rest(.018in.). Any input would be greatly appreciated. I am hoping that this is a woods stack and I can just put it together and ride. I did not try the forks out yet. I am doing a complete/ from the ground up build on a 220R in my garage. After reading so many posts about removing the better part of the big shims from the BV. I decided to take a peek and see b4 I complete the bike.

[TopperHarley]

OK...I really need some feedback from someone out there that has some stack experience under their belt. 21 have looked but no responses???
Funny thing about the base valves was, I still had to file down the peened stud to get everything off. I guess whoever had them apart peened them over with that tool thingy with the + or maybe just a phillips head screwdriver. No lock tite residue on threads at all.

[Indawoods]

Well now... I will say this, I would have rode it so I know what it was lacking first. You need to know where your starting from to know how to get to where your going.....

[scheckaet]

I don't know if it's much help but here is my stack from my 2001 KX 125

shim stack
Base Valve, LSC:
nut
cup
spring
washer sleeve
piston
24 x 4
22
20
18
16
14
11
thick spacer

cartridge:
HS Rebound
nut
thick washer
11
14
17
20
13
23 x 3

piston
HSC
20
25 x 3
22
20
17
12

LS Rebound
15
17
20
22
25
20
o ring
cup
rod

It works ok for me but then again i am no class A rider (more like z )

Myabe you should have a good local tuner check it out or racetech...if you have some $ might be worth it.
Good luck

[IdahoCharley]

TopperHarley - I would just clean everything back up making sure no shims are cupped and reassemble. If you want to soften the compression up a little remove one of the 22s. The 11 is called the clamp shim and the two thick spacers on the bottom are just that spacers (also called a backer shim or double backer in your case) basically a plate so that shims do not wear into the soft aluminum base valve and basically take-up space that would be useful to someone like Dusty.

You have a single stage stack so there is no cross-over shim. If after trying the forks on the bike and want to soften the compression dampening a little more I would remove the 20mm shim.

The KYB on the KX 500 and CR 500 were softened considerably after the open bike MX class disappeared. Most people buying the CR and KX 500 were experienced trail riders and the factory made some fork valving changes to better suit the dieing big bore's .

You can not compare the stacks from your forks with the ones from even same year KX 125 and 250s. Different pistons - different intended uses. The last years of the 500s were basically just BNG years.

Hope this helps

[TopperHarley]

Thanks Idaho, that bit about the valving changes in the later big bore years explains alot. Thanks for shedding some light on the stack. What is BNG years? and who is Dusty?
Inda, I appreciate your criticism. When I purchased these forks they were in need of a complete overhaul. both seals were leaking ,rt leg very bad. it was lacking 1/3 of its oil. I broke them down and installed new bushings, seals, wipers and o-rings. The base valves were covered with sludge and stuff. I wasnt about to put them back in without breaking them down and removing all sludge and chunks of deteriorating teflon which had shedded of the bushings and worked its way into the valve and shims etc. I pulled the mid valves out but they were not too bad. Probably because of gravity. If I had just bolted them on and taken a ride to see where I was, It would have been face down in the dirt with fork oil coating my righ radiator and burning off of my exhaust. Once I got them apart and was confused about the BV shims, I has to ask about it b4 I reassembled them. I will probably install them with 1 less 22mm, per Idahocharlies suggestion, and see how they work and go from there. BTW, I will be getting into my 2003 KX forks soon.same year as your kx125 forks if im not mistaken. Did you get around to revalving or respringing yours? I would like to know how your BV were stacked and what you endedup doing with it etc. If mine has an extremely stiff MX stacks in it and yours had the same and it was necessaqry for you to remove, say, 8 of the twelve 24 mm shims to get the compression dampening to comply with woods riding, I would probably remove those 8 shims and start from there rather than retest something that has already been figure out. Why rub two sticks together when Vince has a BIC in his shirt pocket. heading to st joe on sunday and then Wachita on Mon. the 12th

[Indawoods]

I had no idea the 500 forks were in that bad of condition.... you probably couldn't have gotten a good baseline in that condition. But you will probably not know what they are like unless you rebuild them as they were and then tweak.

I have lived with the 03 forks the way they were stock for 2 seasons now... time to tear into them and go through the shim config ordeal myself. Mine are stiff on landings initially and I want them to float. They kinda go clunk and then absorb. I know that they are from a KX 125 and have .42 springs in them which are probably fine after I do a little revalving. I will try to get to it next weekend since I am getting my daughter this weekend and we are going to celebrate her birthday.... Halloween baby wouldn't you know!

[TopperHarley]

Cool, my Nephews B-day was today. We are celebrating it on saturday afternoon. Cant wait to put a dent in his Halloween candy.HEE HEE HEE

I just got done reassembleing the valves as they were. Some fresh clean oil and we will see where they are at. Just waiting for Ron to get done with my head and and UFO to send my number plate straps.
the Light Speed carbon fiber lower fork guards w/CR brake line routing bracket solved myKX?KDX front brake line routing issue. These things are stout, no guides neded.

[IdahoCharley]

TopperHarley wrote " What is BNG years? and who is Dusty?"

Bold New Graphics & Dusty Abbott (KX500 Desert Racer)

[TopperHarley]

thanks for clearing that up for me Idaho

[TopperHarley]

I spoke with a suspension tuner guy out of illinois yesterday about my 2000 KX 500 forks valving. He stated that the Works seals and wipers I installed were worthless and I need to throw them in the trash or live with the stiction seals. He also said that the base valve on these forks was very limited due to the small oil passages. He said he would reverse the valve so the larger openings would be against the shims which would alow for an effective dual stage stack to be used. He also stated that the mid valve Hype was basically just a hoax and its just a fancy check valve with useless shim stacks. something about the stack being spring loaded so it just moved out of the way to allow oil to flow. Not sure if this applies to other years or not. Not sure if I should take his word for it or not. For what he would charge me, I could just buy some gold valves and install them myself. Of course, I will play with what I have and see if my arms fatigue and head falls off first. Got to find out where they are at so I can appreciate the improvements, dont cha know.

[Indawoods]

I will brobaly just go Gold myself. Nothing fancy needed in the woods...

[IdahoCharley]

I think you will be surprized at how well the forks will work. The KDX is lighter bike and more lightly sprung so removing one of the 22s would have likely added to the overal bike balance. But it depends upon your terrian, speed and ability also. (I agree with Inda though in that a person always ought to have a base line on their equipment.)

The suspension tuner you talked with sent several mixed messages IMO especially on the mid-valve. Many ways to build a mid-valve - at least three come to mind - two of which do not reuse the check valve plate spring.

Don't know about the "Works" brand seals and wipers (quality/stiction wise) but you likely know that new seals will take a good day's worth of riding to break in. Also race tech and others sell a seal grease that helps reduce stiction on standard seals and 'Synergy seals' sells seals which allow some oil residue to wet the seal. (I know this sounds like it is leaking but many people rave about the synergy seals and apparently you do not need a seal tool to install. They have their own particualar method of installation which some find easy and others struggle.)