well,just what kind of pipes are they? Is this a all stock machine? when it is running how does it run? Does it idle fast,slow,is it sputtering? you need to give alittle more info on how it running when it does run. you may j ust need to turn the idle up a bit, clean the carbs and air filter, repack the silencers
If there are aftermarket parts on the bike what are they? do you know what size jets are in there?
good luck...