1980 KZ440 LTDA has goofy carburetor issue

The bike has 13,000 miles on it. I've owned it for 2 years and its had some carb issues over the past year. It was gunked up a couple of times, the needle in the float bowl was stuck about 3 times over the past year. Also one of the slides was routinely getting jammed (about 5 times). So I've taken the carbs off and apart quite a few times in the past year. Now I'm having this weird issue, it seems that I cant dial in the idle screw. It's either too low, or too high. Ill ride the bike around for 20 minutes or so, get it nice and warm. dial the screw in so the idle sits between 1.1 and 1.3. Any engine rev after setting the idle there results in the rpms soaring to somewhere around 4 and staying there. Then Ill try to drop the idle screw back, tiny tiny turns at a time, until the bike no longer keeps the high rpms after acceleration. Once i get it low enough to stop the bike from doing that, it cant hold an idle and will die any time i stop. Help?

I doubt that this info will be useful, but I replaced the drive chain and rear sprocket about 2 months ago.

A "racing idle" may result from air leakage through the carb holders.

Good Fortune!

Check for carb holder leaks (let us know if you need instructions), and check for damaged diaphragms. Ed