Motorcycle Repair: virago electrical problem, yamaha virago xv 750, yamaha virago xv

Question
Hi. I have a 1982 yamaha virago xv 750. Recently  the battery went flat so I jumped it with a car battery...the car ignition was off...however my friends car that I was jumping from has the red terminal as the ground,Lord only knows why, so I got the + and - cables backwards when I tried to jump it. Now I have no electrical at all. I have bought a new battery, but I know I have fried something on the bike. Any ideas at what I should be looking for? Would it be the rectifier? A fusible link? My mechanical skills are pretty limited I'm afraid, all I can think of is to get a voltmeter and start following the wires from the battery to see where it fails. Am I on the right track? Any help you can give me would be greatly appreciated. I checked the fuse box and all are ok. Yet I have no lights, horn nothing. My email is lpooluk@msn.com.
Thanks again,
Andy.

Answer
Hi Andy,

Car and truck batteries are 12VDC like MC batteries, but they operate with much higher amperages. The higher amps can harm the MC's electronics.

Reversing polarity can be harmful, too.

You're on the right track. Get a copy of the service manual for specs and procedures on testing and repairs.

Look for the obvious such as a blown fuse/fusable link. Get a volt-ohm multimeter (VOM) and start tracing circuits.

Call a local Yamaha dealer and ask if they can test the CDI for you. If you must pay the fee for diagnosis, may as well allow them to find the source and advise. Once known, you can replace defective parts, if any.

Respectfully,
Mark Shively