I have a 1982 XV750 Virago that will not start. I can not get spark to the plugs. If I short across the solonoid the starter turns the engine over. Can anyone tell me how to diagnose the problem? I have tried to follow the maintenance manual to test the Rectifier, and Diode Block. It appears that these may be bad, but I am not sure. Either I have reversed the leads for the test or the rectifier is bad. Is there any way to test the CDI unit? Can this CDI be rebuilt?