KZ750N Spectre troubleshooting

Hey there, long time reader, first time poster looking for a little help from wiser minds. I've got a 1982 Spectre 750 with the Keihin 34mm carbs. I picked it up on Ebay and have been trying to restore it back to its old glory. It's got about 17K miles, and I'm having an issue with idle and throttle. It starts and grumbles down low around or under 1k RPM, but when throttle is applied, it continues to stay rev'd up for a while even after the throttle has been released. Opening or closing the choke doesn't seem to matter much to the high revving issue. We reset all carb pilot screws back in to 1.5 turns, then tried 2 turns, but heard and felt minimal effect.

Thank you very much for all the help in advance.

Just spitballing here, but I would assure that the pilot circuit is perfectly clean, try running the air screw in some, as with modern gas I think they need to be tuned richer. I would also inspect the diaphragms for any holes.

Here is a video if you can hear it run. Thanks.

My 83 kz750 did almost the same when I first got it. Spray some wd40 around the intake boots when it is idling high and see what happens. If it changes when you spray it is intake leaks. If nothing changes I would take the carbs off and see if the idle jets are clear. The holes (on mine at least I think they are the same) are SUPER small and took about two hours to fully unclog. I couldnt get a wire thin enough to even get in the whole, Took a lot of carb cleaner and air pressure to finally blast the clog out for good.