The choke on the BS34 relies on plungers. The plungers pull out of their seats when you pull the lever and there is only one mid position so there is little adjustability. If you have the pilot circuit jetted properly, the BS34s will warm up pretty quickly and you can just take them off choke. The Keihin CV34s have more adjustability in their choke circuit as it is a butterfly type which has more or less infinite adjustability as you just close choke butterflies as much as you need and can open them up more or less with infinite adjustment. Problem is, there are no replacement pilot jets so it is fortunate they use this system. If you like Keihins, stick a set of Keihins on your bike instead the Mikunis. Contact me offline if you need help with this. The only component you will have to figure out is the throttle cable as the Keihin uses a different type bracket but it is do-able.
