I have stock bore but completely refreshened.
-Full DG exhaust
-UNI airfilter (no inner spark arrestor)
Cleaned the carb perfectly.
Installed a moose carb rebuild kit to start.
-Tested numerous configuration and stuck with this. ---- Stock pilot is #35 main is #112----
--#38 pilot jot with #130 main jet. I have the needle in the middle, and air screw out about 3-1/8th turns out. Air box lid on. My spark plug has a nice tan color.
If you have a white tip, your lean. If you have a black tip your rich. Try adjusting you needle up or down to. To richen your mixture with the needle, move the circlip down, to lean out move it up.
I would say a 120 is probably enough if you only have a slip-on and stock airfilter with internal spark arrestor. If you have a UNI, TWIN AIR, MOOSE, etc airfilter. Maybe a 125 might be ok.
Ride: 1986 Honda ATC 200x
Following Mods Done:
-Anodized blue block-off plate
-Factory head light and master cylinder guard
-ITP mudlite SP rear tire/Chengshin turf tamer front
-DG reverse megaphone exhaust
-UNI airfilter
-Moose bars/Protaper Grips/MotionPRO twist Throttle
-CEET classic ATC blue seat cover (should of sent it to mosh :-(...)
-Tuned Carb with a 125 main jet
-COMPLETELY restored gas tank
-RED/WHITE PowerMadd Handguards
-1/4" thick aluminum swing arm skid plate!