Mikuni carbs question

undefined Hi all, I picked up a set of mikuni carbs over the weekend and I am hoping that someone here can tell me what they are off. They look to me like they are BS34's off an early GPZ750R but the guy I bought them from thinks they came off a GT750. Someone has sheered the head off one of the fuel mixture screws and it needs to be extracted (will keep me busy some evening). There are the  numbers 1754 671 just above the bowls and if I can find out what the carbs came off originally it will make ordering parts a lot easier. I have attached a few pics of the carbs and a pic of one of the good fuel mixture screws. Any help would be appreciated. Thanks 

Those look like BS Mikuni's off a KZ of some sort.  Key details are the manual pull choke rod on the side of the carbs, and the accordion choke boots on the choke plungers.  You might want to measure the inlet size to confirm they are 34's.  Regarding parts, you can cross that bridge when you get there.  Other than gaskets and O-rings, most of the time there isn't much that needs replacing (other than jets, maybe.)  

Thanks for getting back to me Ed, I measured them when I got them and they are 34's alright, I'm planning to sort the mixture screw and rebuild them and keep them as a spare set for my j1 as they are getting harder to find these days. 

This may help.   gsarchive.bwringer.com/mtsac/~cliff/stor...Rebuild_Tutorial.pdf

You can get an O-ring kit off ebay for cheap. Item # = 352927690992

Thanks again I'm sure that will come in handy