Haven;t needed to rebuild my carb but check this link out.
https://www.motorcycleid.com/suzuki-...-rebuild-kits/
You'll need to put in the year of your bike and you should be able to come up with the kit you need. I see they have a Mikuni kit listed as well as several others. You're problem might not be in the carb, possibly a faulty petcock valve. Several threads here with discussions about this. Have you tried searching this site for carb problems?