If the bike starts but won´t take throttle 1st thing you might want to do if you haven´t already is to completely drain all the old fuel from the tank (Today´s fuel w/ ethenol breaks down incredibly quick) then pull the carbs and have a complete cleaning done either by yourself or a reputable shop. Reinstall refuel with fresh gas and try it. If the carbs are partially clogged your bike will exibit the same symptoms. If you do in fact need a inexpensive CDI you can try cooper´s cycle salvage in Franklin NH. They specialize in late 70´s and ´80´s vintage bikes. Their number there is 603-934-5860. Good luck. GC. :)