1980 kz750 stalls and metal tinging noise

I just got a kz750 Now it has to have the choke on the whole way for like 2mins but still cant turn it down all the way. Lately i try to start it and it will start but then stalls right away the rpm barley goes above the one then comes down and stalls. And theres a metal tinging like a piece is getting tossed around on the left side. And it back fires a tiny tiny bit any suggestions? this is my first bike so not to keen on it.

The engine isn't idling because it sounds like the carb idle circuits are plugged up. And the metal noise may be related; the primary chains make noise when the idle is too low.

Clean the carbs and set the idle per your manual.

Whats the best way to clean carbs never did anything to a bike before.

By taking them completely apart, soaking only the metal parts in carb dip, and blowing all passages with compressed air.

Get a manual first, you can find them on ebay. For good carb parts diagrams go to www.buykawasaki.com and search "Owners Info"

It looks like it is leaking gas out of the carb. And seems to be backfiring out of the carb it will ting and them puff out smoke. And it wont idle higher them 1rpm and then cuts out.