Is it possible that you have a leak somewhere ?
The ca 55 is mostly mechanical operated by vacuum. does it run and accelerate properly?
There are several things that can cause your issue , faulty vaporizer, leaking vaporizer
Leak at mixer (ca55) not burning all the fuel caused by timing first check for leak at ca55 and vaporizer as it is running and not running also all hose and connections ,check timing ,the ca 55 has a plunger that as you accelerate it pulls down allowing fuel and air into engine that's basically all it does the other thing is check timing.make sure engine venting properly and no fuel leak the clicking is possibly the trim valve sounds as though a leak or not getting correct mixture of fuel and air
Without knowing if runs and accelerates properly it's hard to distinguish