Now I'm getting confused. After reading the article it seems that I have been tunning my engine all wrong. They say that the low-speed needle is the one that is on the slide valve. Is that so and if it is what have I been doing for over an year and a half. I use the brass needle to tune the low-speed mixture and it works well. Can someone please explain me one more time which needle is about what, pls. I really am confused.