Buy the first kit as suggested by ST1100 as it contains the accelerator pump bellows that will likely be split on an old carb. Make sure you take plenty of photos if you take it apart together with notes of how it is assembled.
Be very careful when you take the carb apart as Keihin fitted a plastic collar on the main spindle during manufacture. This has a very thin flange that is turned over capturing the spindle, the flange is so thin it cracks during the turning over process. The only way to separate the parts is to very carefully turn the flange back up. Use a hot air gun to soften it otherwise it will crack further and split making it U/S. Do the same when you reassemble it.
Mine fell apart as it was so brittle and I had to drill and tap the plastic part and made a grub screw and washer arrangement to hold it all together.
