I would buy flat slide down draft carbs 39mm or 41mm, it is up to you. You are in luck because of your location, because in the states now you can´t find them, japan stopped sending them here. I have them on my 900rr and i never have to leave 6th gear to achieve any speed I desire. it beats the hell out of a power commander. And the don´t make them for carbeurated bikes only fuel injection.