82 GS550L elecrical
 

Im looking for a CDI box for a 82 GS550L ,d oes any one konw how to test one to see if it works. the bike will start and run, but when it warms up it dies and i have no spark, i have traced all the wires from the coils and ign, it all leads to the CDI box, i have also been told it could be the ign switch, please help I want to ride