Standard Jetting for a 2000 YZ 426

I have looked all over for the standard jetting for my 2000 YZ 426 and cant find any consistent numbers,right now I have a 178 main jet and a 48 pilot jet at 4000 foot elevation. My bike also has an aftermarket pipe on it,would that be the reason the previous owner had it jetted this way? Everything I have read about the 2000 YZ 426 says that I am about ten steps to rich.The plug is also very black so I do believe that I am on the rich side.

Carb Type: Keihin FCR-MX39

Main Jet 162

Main Air Jet 200

Jet Needle OBEKR-4

Jet Needle Clip Position 4

Pilot Air Jet 100

Pilot Jet 42

Pilot Outlet 0.9

Pilot Screw Turns Out 1 3/4

Bypass 1

Starter Jet 72

Hope that helps. :crazy:

Yep, that's right...all except I thought that the main jet was 168, but I don't have my reference sheet in front of me, I'll have to double check that one, but the rest is good.

Yep...voodoochild is right all across the board. I was just remembering it wrong. :crazy:

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now