[randresen]

I have a 2004 CRF150F and after several jet changes I'm not sure which needle jet I currently have installed in my bike the power up needle jet or stock. They are designated by a 3 letters right near the top of the needle.

[Back2-2]

I am just taking a stab here - But I have only run into needles that are 4 letter designation that are factory needles
[ Keihin or Mukini] So, if you have a 3 letter needle that may be the aftermarket needle ? That's if I understand your question as to OEM or an aftermarket ?

[Aussiecrf230]

I believe the Full Power needle for the CRF150F, 16012-KPT-921 is marked B18L.
Hope that helps.

There are 3 character codes on some standard needles, either that or poorly stamped.

[randresen]

Thanks, I was indeed wrong it is a four digit alpha numeric number such as B18L. This helps a lot because I do in fact have the B18L needle jet installed currently.