KDX 250 1991 Model E1 (New Rider)

Joined
Nov 19, 2003
Messages
14
Likes
0
#1
Hi I have a KDX 250 1991 Model E1 and I have just rebuilt bottom and top. however the bike seems to be fouling plugs and runiing way to rich. The main jet is a 185 any help would be greatly appreciated.
 
Joined
May 12, 2003
Messages
17
Likes
0
#2
Welcome!
I also own a 250 KDX but 93'er.
I think 185 is far too rich ( if stock ) My baby was too lean 144er jet.
After surfing in this forum I could see that the most used jets are betw152 and 165.
By my bike I installed 155 main and 38 pilot ( of course after two days playing with plugchop...etc.) but in wintertime 158 and 40 is the best for me.
I have a SPES pipe but everythink else is stock.
Greetings fom Hungary
 
Joined
Nov 19, 2003
Messages
14
Likes
0
#3
Excellent thanks for the info.

I have a pilt jet of 38 already just need to change main jet I spose.
 
Joined
Aug 30, 2003
Messages
41
Likes
0
#4
I tried a 160 main and 40 pilot with stock needle, fmf pipe no airbox cover, and I had a real bad lean spot at upper midrange, it just bogged, I put the 165 (stock) back in with clip in top position, my bottom end is better, but I'm to rich at the top. I'm going to try a richer needle with the 160 main and see what happens. I did run the clip in its lowest position with the 160 main and it was still way lean in the upper midrange.
 

dirt bike dave

Sponsoring Member
Joined
May 3, 2000
Messages
5,349
Likes
3
#5
The KDX250 also benefits from a leaner slide.  You can buy a new slide with 1mm more cutaway or file approximately 1mm off the bottom of your stock slide.

Most guys run a plug that is one or two steps hotter than the BR9ES Kawaski recommends.
 
Joined
Nov 19, 2003
Messages
14
Likes
0
#6
Thanks for all your info

I have a 175 to try and put in it but prob will have to go lower by the sounds of it.