Help with different Keihin jets!

I bought a '09 yz450f, that had a JD kit in it. It was jetted for a different altitude, so I need to lean it out a bit. The Jet on the left is a 170 from the JD kit, and the 2 others are a 168 and a 165 from the local dealer. Notice the "collar" inside is quite a bit deeper on the jets from the dealer than the JD one. Also, the JD one has a little sort of half star design and the others say "AB" on them. Can anyone help me out with the difference between the two? And, will going from a 170 "shallow collar" to a 165 with the deeper one have the same effect as two that are the same?

Any help would be greatly appreciated!

IMG_0133.JPG

The star is Keihins logo

JD only uses Keihin jets.

All actual Keihin jets flow the same, so a 170 is a 170 (assuming both are undamaged and spotless). There are aftermarket companies selling knockoffs that have been reported to not match exactly. I suspect the dealer jets are not actual Keihins but knockoffs.

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