1981 CB750c Carburetor Issues

[RMBillings]

So I need some help with carburetor issues on my 1981 CB750c. I bought the bike as a none runner so I went through the factory carbs and validated the factory jets sizws and all jets were free and clean. When I get the bike running it is running rich and the rpms will not come down from 1,800. I backed the idle adjuster off all the way and unhooked the throttle and choke cables and it did not help. I also validated there is no vacuum leaks by spraying carb cleaner around the boots and carbs and the rpms did not go up. Any help would be appreciated.

 

[BAHNST]

?Ignition advance/timing issue a possibility...do the Rpms "hang"?

 

[bruno_b]

I would check the ignition timing and in particular the autoadvance device.