Originally posted by albertlam
Always hear many people say about the Mid Range needle, when you don't know how to tune it, don't touch it.
Then, how will you guy consider a person to know how to tune it? I'd like to learn how to tune this as well.
I repeat it, for those who haven't noticed:
The brass screw located at the other side of the low-end needle isn't a needle. Varies the position of the fuel jet on the intake venturi.
The main reason of this adjustment of the jet is move the point where the low-end needle actues and where not and the fuel flow is dictated by the high speed needle. This is the most plausible explication that I find for this bad called mid-end needle.
For starting to adjust the position of the Jet, you've to get a steady hand doing carb adjustments. I don't feel comfortable touching it (like many others)... best bet is leave as is and play only with the high and low-end needles. You'll probably get a 97% of your carburation playing only with those needles and ignoring the third screw.