Jet sizing 38mm PE DG Keihin carb on LT250R

[GNDan]

Im a new guy to Suzuki and this site looking for the right size jet selection size for my carb it is as listed DG 38mm Keihin carb on a 1987 LT250R, i bought it from and guy who used to ice drag it. It has a huge jet in it now it is a 180 which is way to large runs way to rich to run after about 2/3 throttle. It has a fmf explansion pipe and silencer, and K&N drop in filter. The bike used to have a larger bore and full ported top end before failure, WHERE DO I START AROUND FOR SIZING?

Any help is appreciated, Dan

[greeny250sx]

well i'm running a 38 on my ktm 250sx..mine comes stock with a 172..try that and go from there..