Re: 1978 cb750 carb swap

Posted by Re-run on Jun 16, 2012; 3:50pm
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/1978-cb750-carb-swap-tp3911046p4023080.html

The needles control the mix as it transitions from the idle jets to the mains. It wouldn't do anything to control your idle mix.
Easy way to say it is they control how rich the mains are and when. Picture it like this, visualize the needle in the main all the way down. Now see the fuel going through the jet as the needle is raised, the more it goes up, the more fuel the needle allows. Now, imagine changing the clip location, see how it raises or lowers the needle in the jet and thus how much more or less fuel is coming at the same throttle position. For example, at half throttle, if you lower the clip it raises the needle thus allowing more fuel in at half throttle.
I hope I was clear enough on that.
It still does not change your over all slide position and thus throttle position. It changes the amount of fuel coming in the mains so you can lean it out or richen it up. Remember, raising the needle makes it richer, lower is leaner.