start by removing every other stock weight, gets you to 39 grams total.
i was pretty happy with my stock urban plus malossi kit with 27 grams total, 6 Dr. pulley 4.5 gram sliders, but I weigh 160. I was using the stock carb/airbox/autochoke with a 90 or 92 jet, it's been a few years.
you can get 16 x 13 multi weight tuning sets on ebay to help dial in the right weight.
treatland sells a few bolt on clutches that take standard springs if you want to experiment with that, or drill out the arms on your stock clutch arms to lighten them.