KDX 200 jetting for high altitude 5000ft-10000ft

[degunboy]

Hey guys! I have a 1986 kdx 200 that is definitely running too rich for my altitude ( black splooge coming from silencer, not as much power as it seems it should have). In my manual it says the stock main jet is 300? So I need to go smaller right? anybody running an older kdx in high altitude? I have no experience with tuning carbs so any info would be appreciated! thanks!

[Joshx221]

Have you looked through the jetting sticky at the top of this forum?? I don't even own a KDX and have seen a few high alt. jetting specs in that thread. Spend some time reading through it, good grief. Even if its a different year the base principal is the same.

Edited May 13, 2013 by Joshx221

[KDXGarage]

Get the pilot adjusted first, then go from there. ...needle clip...main jet

There is no air screw on a 1986 KDX200 carb before someone mentions that type of adjustment.

[degunboy]

Looked through the whole thread and there arent any pre 1989 kdx's in there. I dont know if it has an obsure carb or what but it says the main jet is a 300. which seems ridiculously big compared to the numbers of other peoples jetting. I dont know if I should order something online or what? I talked to a shop near me and they said the biggest main jet is around 200 which seems like it could too small to start with. should I go down a couple sizes to start considering the high elevation I will be running it at?

[KDXGarage]

FIRST thought is to never go back to the guy you spoke with. It is a Mikuni. They are quite common.

[Joshx221]

I apologize. In my haste I must have overlooked or mis-read the year of your bike.

[KDXGarage]

What? You are right, the basics are the same for his bike...roughly start at pilot, then needle, then main

I don't know why they changed, but I want to say 320 was stock on my 1987 KDX200.

[degunboy]

I actually found a guy on craigslist that had an 87 KDX 200 and I asked him what the jetting was and he said 42 PJ and 164 MJ. He said its jetted for high altitude so I'm thinking I might try his set up. What do you guys think?

[KDXGarage]

You don't have the owner/service manual, do you?