I have a 79 zx that runs rich when first started. I think it runs rich the whole time after it gets warm also. I was wondering how to lean it out, possibly other problems that could contribute to this. The cold start valve seems to work ok; tested it like it says in the manual. I tested the Air regulator, and it seemed to be ok; cleaned it out. i was thinking of adjusting the air bypass screw, but it looks like it might screw it up, since I don't have n exhaust meter. I think I will test the thermotime and temperature switches. Is there anything else to check? Any advice would be greatly appreciated.