its an ex "pimp my cb"bike,looks bloody good,ill have ten at that price,have a gander though the faq section and download the workshop manual,the 500 one is the same more or less,you can ,or should drop the bowls off the carbs to get the final finest crud out that will block the tiny jets in the idle circuit,you can replace the needle and seats without dropping the carbs if your not ham fisted and check the float heights as well,ill guess a little crap has gotten stuck and just needs that final clean out,good luck and welcome.