Bleach

The air line you speak of might be the valve cover vent. The plate that holds your filter on top of the carb has a hole cut in the bottom of it. Find a metal piece that fits through that hole but has a lip on the back side that prevents it from going all the way through. Then run a rubber hose from the valve cover to the outside of that connector and clamp it on. That takes all the smelly gases back into the engine instead of into the engine bay and then inside your car. No vaccumme lines need to be hooked up to the carbs themselves. The Webers probably have an electric choke connection, but your ZX won't have anything for that. You can remove the electric choke round thing and hook up a custom manual choke if you wish. Auxillary has this Weber setup.