YAMAHA 1976 YZ125X CARB/JETTING

[jimg1au]

bike almost ready to test run.factory carby 34mm with 310main i built a carby to factory specs all but 2.5 slide against 3.5 std.i have run 150mm of fuel throught it and it was very dead in response.the carby which came with the bike is a 32mm with 230 main.this is for dirt track only and a biger carby on a 250 or 400 is good.this is the very first 125 i have ever owned(naten talked me into it)so any help would be good.i am thinking it should be no different to my cz400 in how to jet but would like some proven jetting to help me get it right.
it starts and idles fine
jim

[DJRacing]

I run a standard carb in my YZ125X and it runs fine.

[wmc83]

my 125j has a vm34 and its main jets only a 260 and I think thats to rich 310 sound way to big IMHO

[jimg1au]

any one else with a yz125 34mm carby know there jetting

[mboddy]

YZ125X standard carby is 34mm.
310 main
P-8 nozzle
6F15-2 needle
3.5 cutaway
60 pilot
2.0 air jet
80 starter jet
1.0 air screw turns out

[jimg1au]

thats what i have got but only 2.5 slide runs very rich.

[mboddy]

Just file 1mm off it and you will have a 3.5.

[Freakshow]

Less volume.... less margin of error