KZ250 Running Rich

LOL, I am stumped for the first time in 46 years! I have a 82 KZ250CSR. On start up it needs no choke. Idles fine, won't take any throttle without sounding like it's loading up and spitting back. I removed air filter and it runs a little better. Now, here's the crazy part. After it idles for 10 minutes, the idle speeds up a little and then it takes throttle and runs perfect! I don't get it! HELP!!!
I pulled carb apart and cleaned and adjusted valves making sure I had clearance.

hello Buffalo joe.
I am little stumped as well. It seems like when the engine has warm up and things have expanded it cures the problem. The spitting back is it from the carb or the exhaust side?
first, I would look at all connections with the carburettor, the inlet manifold and air duct for air leaks. Look for cracks in the manifold and air duct and the connection between manifold and cylinder head.
Other than that, recheck your ignition setting and carb setting.

Sounds like your to rich. On the other hand it sounds like your to lean.
Maybe idle circuit too rich and mid range too lean?
First, I would make sure idle circuit is right. Start engine with no choke or throttle. Let idle for 10 minuets, Shut down and check plugs.

the spitting back is from the intake side. I loosened the intake valve and it now has at least .006 clearance to the point of ticking, but I wanted to make sure I eliminated that concern. The exhaust has .005 clearance.
I sprayed gas around the intake boot, no diff.
I also might add that when it's idling I can twist the throttle (without air filter) and it stumbles like the choke is fully closed and I can see some smoke from muffler.

I ordered a new CDI module and of course they sent me one that wont connect and none of the wired are the same color, even thoug in 2 places in their ad it says that it fits the 250 CSR.

I also ordered a new jet and needle kit for the carb.

Thanks so much for all of your inputs. I worked for Kawi from 6-79 as a Cert'fd mech and never had a problem quite like this but the intake boots were new then.