the mechanic put a cdi from a yamaha I think.
Hey Dragon,
I don't know how knowledgeable you are about motorcycles, so please don't be insulted by this question, but are you sure we're not talking about a regulator/rectifier rather than a CDI ?
Because to my very limited knowledge of these things, it is very unlikely a digital igniter (or CDI) from a Yamaha will work in your bike, but regulator/rectifiers are somewhat interchangeable ( I've been running a Honda reg/rect for a year and a half now ).
If it is a CDI swap and it works, please post the details.
Regards,
Steve