depends on the modifications you already have.. a mostly stock bike would be good with a 28-30mm and still fit the stock intake setup and modified motor would be good to around a 35mm with a new intake box and boot. i like the keihin pwk carbs best.
well
its mostly stock
i have a rebuild i cant recall the bore.
and i port and polished it.. this was all back in the day.. now im paying attention to her again
stock exhaust