Has anyone heard of or used these carbs?

Hey guys I'm kinda out of ideas on why the bike won't start up except carb issues. I bought the bike running and then rebuilt the carb and now it won't idle, it'll turn but then die. So I was looking at options on what to do and came upon this https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F172859468917. It's a mikuni slide carb that fits my bike supposedly perfect. Have any of you guys used this? Thanks. via /r/CafeRacers https://www.reddit.com/r/CafeRacers/comments/9zsn1n/has_anyone_heard_of_or_used_these_carbs/?utm_source=ifttt