Kdx 250 sr Japanese version rear shock

Discussion specific to KDX models not sold in the USA
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Has anyone ever fitted a kx rear shock onto a kdx 250 sr Japanese version 1993 .. I haven't got any rebound on my rear shock. When I'm landing I'm being bounced back into the air again.. I've set rider sag. Changed fork oil to 10 w . I've seen people talking about revalveing ? It would be nice just to bolt a shock straight in...
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

How long has it been since you had the oil changed or any work at all done on it?
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

To be honest I haven't touched it. It's nice and dry. I know it's the wrong bike for jumping. I have the sore wrists to prove that...
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Very low mileage to only had 4700km on clock
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

KDXGarage wrote: 02:05 pm Mar 25 2019 How long has it been since you had the oil changed or any work at all done on it?
Ok oil change it is.. would 10 w be any improvement ?
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

Sooo, your shock's oil was put in about 27 years ago. :hmm:

In all seriousness, I would STRONGLY suggest an oil change. Check the internal parts as well. 5 or even 3 weight is my preferred method. KYB K2-C shock oil (stock) is great.

I used to work on suspension a little around 2005. With just a rebuild of new stock KYB parts and fresh oil, most guys were amazed at how much better the shock worked. For example, someone posted earlier today about a fair amount more power since he just did his top end. Going back to a fresh start really works out sometimes.



Here's an off-topic UK related video, actual video footage of me and Newcastle Brown Ale: :drinkers:
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Fresh oil it will be. So 5w Newcastle brown ale lol..
I'll look for that kyb oil. How much nitrogen do you normally put in gland? I only way 168 lbs...
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

150 psi

Can you post a pic of the shock? I assume it is similar to other KDX shocks.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Yes I'll have a look this weekend. Thanks
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

You're welcome.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

If you can see photo. I'm sure frame was hitting the ground. I blew fork seals that day to. I put new bushes and seals in forks and 10 w oil. Adjusted rider sag. It's not bottoming out now just bounces me back up in the air...
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

This is with 10w fork oil and back suspension set up for me... I'll be changing oil this weekend .....
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

Make sure you have the correct rate springs in the forks and on the shock. Jumping that high is a little more than just zipping through trees.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

Seems like front springs have to be custom made for kdx 250 forks. 43 mm tubes. It's quiet firm on a rough road/track . It definitely feels like it's a damping problem not enough oil restriction . Going to get on it this weekend with oil change ...Motocross tracks wasn't my intention for the kdx. My son and daughter both have 85s and keep talking me into going MX with it ..
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

Yeah, you're not going to have it work well at a MX track and in the woods / trails. Pick one or get two sets of forks and shocks.

What is your weight in full riding gear? You might be able to get some 1993 - 1995 KX125 / KX250 springs for it and use a couple of washers. Spring length is 487 from Race Tech (wwww.racetech.com)

Someone has some 43's on eBay USA right now that are designed for KDX250.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
Dan 250sr
Supporting Member III
Supporting Member III
Posts: 93
Joined: 03:01 am Nov 06 2018
Country: Japanese version
Location: UK Hertford

Re: Kdx 250 sr Japanese version rear shock

Post by Dan 250sr »

:boogie: bought.... just had a quick read up, saying might have to trim plastic damper rod to and also said about spacer needed. Nice one cheers
User avatar
KDXGarage
KDXRider.net
KDXRider.net
Posts: 14047
Joined: 06:45 am Nov 01 2004
Country: United States of America
Location: AL, USA
Contact:

Re: Kdx 250 sr Japanese version rear shock

Post by KDXGarage »

I looked again today and did not see them. Do you have a link to what you bought?

That post you talked about sounds like it was from me.

The fork spring can get stiffer BY...
being shorter (can't do that in the forks, must stay the same length) OR..

the coils being thicker (which is how it happens on fork springs).

When stock, there is a gap between the outer diameter of the spring guide and the inner diameter of the fork spring.

To make a fork spring stiffer in an USD fork, the spring manufacturer makes the coils thicker. The OD of the spring must stay the same. THEREFORE... as spring rate increases, the ID of the spring decreases. This leaves less of a gap between the ID of the spring and the OD of the spring guide. In order to maintain a decent gap, it might be necessary to modify the spring guide to keep a decent gap.

Fellow member and friend treelimb brought his 1997 KDX200 over on Wednesday. He has a KLX300R front end. Someone had put 0.46 Kg / mm rate springs in the forks. We put the stock springs back in. There was very little gap with the 46's.
Thank you for participating on kdxrider.net. :bravo:
To post pictures from a device: viewtopic.php?f=88&t=24128
User avatar
doakley
Gold Member
Gold Member
Posts: 1241
Joined: 02:58 pm Mar 10 2016
Country:

Re: Kdx 250 sr Japanese version rear shock

Post by doakley »

Not sure I would swap forks back and forth for MX use. I’d go buy a used KX250 and use that when the kids wanted to drag me to the MX track🤣😂🤣
Post Reply