The K0/K1 was noted for rich-running problems like this, especially in Police work. That's one of the reasons why it was quickly abandoned in favor of the KZ1000, which idled very lean (for emission reasons), but worked out well in heavy traffic.
The K0 usually came with 120 mains and a 40 pilot jet. We often changed these to 115 mains and 38 pilot jet, right out of the crate. In Colorado, we went to 110 mains and dropped the needles 1 notch on top of that. Many owners went on to install 105 mains at this altitude, but that's pretty lean for Texas.
This bike also overheats the carbs when too hot, which tends to make today's gasolines boil in the bowls. If you plan a lot of heavy city traffic, you can try dropping the float level 1 or 2mm (go to 27 or 28mm height, upside down). If you do this, stay with the main jets you have until you try it out for a while. This will help keep the overflow from the boiling at bay, but will cause a loss of some top-end speed.
Or, like Bob said, don't drive in parades...
