mmmmmmmwell not sure about your clunking noise as its a bit vague on yoour description of that but i would say that the new rollers are too heavy still,its ounds like the transmission is gearing up and stopping the engine from revving and creating the rigth amount of back pressure that it needs to make it work with the new free flowing exhaust,try this and see what happens,take out the new rollers and put back 3 of the old ones in a triangle arrangment,see if it p[icks up better then.also i what are the new jet sizes you have used and what were the old sizes?
adam bike doctor
August 2010