Mikuni needle & jet question?

[matt]

After years in a box I am finally gettin around to sorting out an old
86 kx125.
I need info on mikuni jets and needles. I have the choice of a DG or
a pro circuit pipe. the carb (mikuni) currently has a 350 main, 6DK
needle, ? jet-needle? and .35 pilot.

the stock config is 340 main, 6j7 needle, r-8 jet-needle, and .35
pilot. My question is Where Can I find out the specs. on these
needles? which is richer, leaner, etc. Do I have to use a matching
jet-needle with a particular needle?

the kx parts fiche lists optional jet-needles as S-2, R-4, R-6, S-0,
R-8
Dose anyone know how to interpret the needle letters and #'S?.

I have no idea what the carb was set up for previously.
any experience with which pipe might be better?
thanks
matt

[matt]

matt...@yahoo.com (matt) wrote in message news:<f0511887.0206...@posting.google.com>...

also when I rev the bike (in neutral) to WOT the rpms will bounce up
and down, and it dosen't rev as high as it should.
is this too lean a main? when riding there are still some 1/2-3/4
flat spots.

I have been playing with the needle a bit and have seen it get
better..

I currently only have some fmf 4-stroke silencer packing. can this be
used with a 2-stroke? or will this effect performance?