yz250 jetting

just traded my 450 for an 05 yz250 and have some questions about the jetting. I've had 3 rides on it so far and it has a strong midrange bog. starts easy and runs great in 3/4 to full throttle.

I ride at 4,000-6,000' elevation

fmf pipe with stock silencer and new packing

stock reeds but will put in V-Force 3 reeds soon.

Oil: Maxima Castor 927 40:1

170 main

N3EJ Needle with clip on #3 (right in the middle)

50 pilot jet

air screw out 1 1/2 turns

took out the plug and it has some build-up and color is black.

What I plan on doing:

45 Pilot

move the clip up 1 (moving the needle down)?

I've never messed with the needle so I just wanna make sure I'm starting in the right direction. also I'm not familiar with the different needles...what needles would be good to look into for my altitude?

also, what does that tiny jet on the side do? it says its a 50.

thanks in advance!! so stoked on my YZ!:cheers:


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