Umm, what did you do to improve it? Give us some clues. And WELCOME to Motorbicycling!
Thanks Professor. It has been a while, but my first mistake was partial disassembly of the carb and adjustment of the throttle cable. I've also got the adjustment screws on the carb in who-knows-what position compared to optimal.
It will start but won't run smoothly as before I started messing with it. I've had it parked fo a year so it is hard to remamber exactly what I did to mess it up!