I think by the look of my plugs I'm running a bit rich [ZX6R carbs, 1.6mm mains, needle on the second notch].

To lean it off should I go for smaller jets, or will dropping the needle down a notch lean off as well?


Stu

There are several settings to think about, done in this order:

1. WOT - wide-open throttle. This is controlled by the main jet, and has to be set first.

2. 1/4 to 3/4 throttle. Set by the needle, usually by position up or down, occasionally by replacing it with a different length and/or taper.

3. Almost closed throttle. Set by the pilot screw.

I'm using 1.3mm mains on CBR600 carbs, with a 1660cc motor. The mixture is correct for WOT and tick-over, but rich on the middle bit - but unfortunately I have fixed-length needles.

HTH,
David

David, you can always put a washer under the head of the needle.

Mine needs to go down, not up!

I did think about that afterwards.

Yup. A washer under the needle works well. Let me know if you fancy borrowing a colortune... Worked well for me (that and a wideband lambda sensor )!!!!