Author Topic: 87 kx250 shock options  (Read 6387 times)

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Offline Oblivious Maximus

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87 kx250 shock options
« on: April 05, 2014, 04:24:58 PM »
Hello KX Riders. I've been a member for a year and a half or so and want to thank everyone for sharing their knowledge and experience which enables a lot of people to be more involved in the maintenance of their bikes and the sport.

I have an 87 KX250 which I've owned for a year and a half now. It runs great, daily driver around the property and weekend "woods warrior".

 This past winters projects included a nice old PC Platinum pipe, FMF turbine Core and suspension rebuild which is going well except for the shock.

 It's a stock 87 KYB with stock spring. No oil leak, no bottom out bumper, and no evidence of ever being dismantled. Before I took it apart the nitrogen pressure measured only 22 psi and the fluid measured roughly 10oz. The bladder seems fine and will hold 100psi air pressure which I used to test it.

 I did find an area of wear in the bore at the mid section and the piston drags when it hits it. So I'm guessing this shocks shot. I'll likely refill it and use it till I find a replacement as the snow is finally melting here in Michigan.

 So I'm wondering if anyone knows what year shocks may fit the 87. Kawasaki part list says.. 87 KX 250 and KX500 only but I find that hard to believe as KYB wouldn't likely do that. I've been following Motopunks 87 project but didn't want to butt in as that thread is a work of art in my opinion.

 Any help will be appreciated. I was considering racing at our local MX track last summer but those other old buzzards in the 50+ class have cushy new bikes. But they also have a vintage class I'd like to try this year.
 
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Offline sandblaster

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Re: 87 kx250 shock options
« Reply #1 on: April 05, 2014, 05:05:17 PM »
I don't have measurements for the 87 but I can get them for a 88.
I have measurements for a 92 here:
http://www.oem-cycle.com/forum/viewtopic.php?f=48&t=372&p=1248#p1248

94 here:
http://www.oem-cycle.com/forum/viewtopic.php?f=48&t=377

Here is some I recorded for a 2000:
KYB - SPRING THICKNESS: 11.9MM OD - SPRING DIAMETER: 89MM - SPRING LENGTH AS MOUNTED: 270MM - UPPER MOUNT TAB WIDTH: 22MM - UPPER MOUNT TAB HOLE ID: 10MM - LOWER MOUNT OUTSIDE WIDTH: 37.2MM - LOWER MOUNT INSIDE WIDTH 22.7MM - LOWER MOUNT HOLE ID: 10MM - EYE TO EYE: 454MM
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Oblivious Maximus

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Re: 87 kx250 shock options
« Reply #2 on: April 05, 2014, 05:36:20 PM »
Thanks for the quick reply Sandblaster. My springs not mounted but nothing else in common with the 92, 94, 2000 dimensions. Info on the 88 may be helpful. The 87 is a tough one to find some parts for though the 125 and 500 shared parts with the 250.

Both the top and bottom mounts on mine are round eye bolt type connections. No clevis.

Thanks again, I do appreciate your help.
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Offline sandblaster

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Re: 87 kx250 shock options
« Reply #3 on: April 05, 2014, 06:08:54 PM »
Here's a pic of the 88
The four stroke engine: That's one stroke for producing power and three for wearing the engine out.

Offline Oblivious Maximus

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Re: 87 kx250 shock options
« Reply #4 on: April 06, 2014, 03:20:15 AM »
This one has the same top and bottom mounting configuration with some differences in the adjusters. So it looks much closer to a match.

I'll try to post some measurements later today. Just need to finish last weeks work and reinstall the spring.

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Offline motopunk

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Re: 87 kx250 shock options
« Reply #5 on: April 07, 2014, 04:38:59 AM »
the 88 shock is 10mm longer than the 87..  i have an ´88 shock in my spares and as i tried it , were my legs to short, to reach the ground,  :-D

fitment of the 88 shock in the 87 bike is great, but it needs a little bit modifying with spacers in the inside to shorten the length -10mm... thats all.
« Last Edit: April 07, 2014, 06:00:37 AM by motopunk »
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

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Offline Oblivious Maximus

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Re: 87 kx250 shock options
« Reply #6 on: April 08, 2014, 02:18:53 AM »
Thanks Motopunk. I was pretty sure you would have some good info to go along with Sandblasters pics and dimensions. Between the two of you not much goes unsolved.

I was hoping to move up a few years in models but the 88 shock is more plentiful than the 87 and I'm 6 ft. tall with long legs. Next problem is finding one in better condition than mine. Many times these old parts share the same problems. The wear mark on mine seems to be at the point the piston would rest when the bike is parked. For the year and a half I've owned it the shock seemed to work fine for my simple needs though a little soft. I'll add a bottom bumper and refill and recharge it for use till I find a replacement.

Last of the parts will arrive this week, a little welding on mount tab to fit Platinum pipe, assembly this weekend and my first ride on the 87 since last Nov.

Again thank you both for your attention and information. That's what makes this place great.
Where the Hell is "Easy Street" ?

Offline motopunk

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Re: 87 kx250 shock options
« Reply #7 on: April 08, 2014, 03:43:34 AM »
Thanks Motopunk. I was pretty sure you would have some good info to go along with Sandblasters pics and dimensions. Between the two of you not much goes unsolved.

I was hoping to move up a few years in models but the 88 shock is more plentiful than the 87 and I'm 6 ft. tall with long legs. Next problem is finding one in better condition than mine. Many times these old parts share the same problems. The wear mark on mine seems to be at the point the piston would rest when the bike is parked. For the year and a half I've owned it the shock seemed to work fine for my simple needs though a little soft. I'll add a bottom bumper and refill and recharge it for use till I find a replacement.

Last of the parts will arrive this week, a little welding on mount tab to fit Platinum pipe, assembly this weekend and my first ride on the 87 since last Nov.

Again thank you both for your attention and information. That's what makes this place great.

on this site is to much knowledge for only one of us...  :-D  ...

i´m not sure about the fitment of the 89 kx125/250 and kx500 ´89-2004 linkage. if this would work, you could use also the 89-2004 kx500 shocks in the 87 frame.
i plan to upgrade my 87-racebike with an wp- or öhlins-shock , because i installed a "wp extreme 50" conventional fork (by the way : first short testride on sunday and the fork works perfect  :-D ) in the next time i have to figure out the fitment of the kx500 ´89-2004 linkage to the 87 frame. that would open many shock-options...  :-)

here is my bike build...  http://www.kxriders.com/forums/index.php/topic,11655.new.html#new 
« Last Edit: April 08, 2014, 04:54:36 AM by motopunk »
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

---  www.der-motopunk.de.tl  ---

Offline Oblivious Maximus

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Re: 87 kx250 shock options
« Reply #8 on: April 08, 2014, 02:56:01 PM »
I followed your 87 thread from the beginning and you have done some impressive work.

In fact I have a kinked 87 pipe just like the one you repaired with the new inlet. I may also do a fork upgrade if maintenance doesn't improve my stock suspension.

Good to hear your new forks are working great and you have front brakes too. I'll be watching your progress.
Where the Hell is "Easy Street" ?

Offline motopunk

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Re: 87 kx250 shock options
« Reply #9 on: April 09, 2014, 03:06:56 PM »
I followed your 87 thread from the beginning and you have done some impressive work.

In fact I have a kinked 87 pipe just like the one you repaired with the new inlet. I may also do a fork upgrade if maintenance doesn't improve my stock suspension.

Good to hear your new forks are working great and you have front brakes too. I'll be watching your progress.


thanks... :-D ... my own version of worksbike..

the ´89 41mm usd-forks were installed by the preowner, but you could only adjust compression..the 87 fork and shock are also not bad, but i took it into my spares and decided to upgrade slowly step by step to the best parts that will work with the 87-frame... the fork swap to the ´99 husaberg wp-fork with the 89 kx-triple tree was easier than i thought before.
every time i come in my garage and see my 3 unique bikes, i´m a bit lttle proud to my own, what i have done there with my always low budget out of the scrap-bikes that i bought.  :wink:

and in fact, many parts for the older bikes before 1990,are easier to find in usa and uk , than here in germany. so its sometimes quite to expensive and not worth to order parts, that have to come half around the world with big extra-pay for import-tax and customs clearance ...
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

---  www.der-motopunk.de.tl  ---

Offline Oblivious Maximus

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Re: 87 kx250 shock options
« Reply #10 on: April 12, 2014, 03:23:26 PM »
I think I know how you feel when you walk into your garage. The bikes are like family. You know them inside out and they have their own personality. I've never owned a new bike. I sold my 1968 BSA 441 victor 25 years ago when it was 21 years old and I thought I was done riding. I bought my 87 KX a year and a half ago and have never had more fun on a bike. I also have a 1980 CR80 I'm fixing up for my grandkids, my wife has a 2003 XR 100 and my son has an 05 KX 125. We have hundreds of miles of trails near us here in Michigan and spend a lot of summer time in the woods.

I got my shock together and bled and the rough spot can no longer be felt it's quite smooth. The bottom adjuster was leaking so I removed the roll pin and found the clicker gear was not aligned with the gear which turns the needle. After some adjustment and reassembly all is well.
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Offline motopunk

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Re: 87 kx250 shock options
« Reply #11 on: April 12, 2014, 07:03:31 PM »
you live in riders paradise...  :wink:  ... here in germany you are always the outlaw by riding in the woods with street legal or mx bikes..everywhere you could find the yellow signs with the black owl , tha means saved for nature or the other thing: its simply private property. but sometimes i did it for a short ride in the last years..you must only know the right ways, that the police cant follow..  :evil:  :wink:

nice to hear, that your shock is working well again...  :-)
big 2 stroke bikes are weapons for real men, who don´t fear death or devil. ;O)
´83 kx250, ´87 kx250 (with 360 big bore), 87 kx500, ´93 kx500 sfc

---  www.der-motopunk.de.tl  ---