thanks for the input. i didn't purposely change the mixture, but who knows. maybe it was slightly off because last time i mixed the gas right in the tank on the moped, and this time i mixed it in a gallon portable tank. i'll try diluting it.
the carb has no idle screw and there are no modifications done to the bike.
i always check the pipe for drips and there are none.
i'll try a plug chop (always hated that term) if things don't improve.
i thought maybe my engine was complaining about the new terrain i have been making it conquer. perhaps it only wants to be revved at stop lights just like those harleys.