I have a small problem. i have a 1990 ls650 i bought from a local bike mechanic, in the morning i pull out the choke and it starts up fine no twisting the gas and idles for about 1 minute and dies i do the same thing again and this time before she dies i push in the choke and twist just a little and the carb starts puking gas out of the tube, so to keep it idling i twist in the idle screw on the left and runs fine but later in the day she runs at a very high rpm so i twist it out untill its normal, i don't want to keep twisting in and out the idle screw and the mornings are not so cold, she just takes so long to warm up about 15 minutes!

Try to run it with the petcock at PRI to see if it helps. It will narrow down where the problem is.