Motorcycle Repair: blown main fuse CB900C, thick copper wire, honda cb900c

Question
Hi Jan,
I have a 1981 Honda CB900C with just under 8,000 miles. While riding this weekend around a very sharp right bend the bike went dead. It was the main fuse (30 amp fusible link) on left side under cover. I replaced with spare and it immediately blew again.
What would cause this?
Thanks,
Ken

Answer
If the main fuse blows like that, you have a dead short in the loom somewhere.  It will not be in the battery or solenoid connector since they are not fused, but all of the other components are.  Usually you will find that the loom itself has chafed against the frame somewhere and the positive wire is shorting out.  It could also be in the ignition switch, etc.  Sorry I cannot be of more help, this is not an easy fix.  However if you replaced the fuse with the spare that was under the cover, that fuse may have been too old.  Try and get a new replacement, but they are tough to obtain, a lot of people put 30A new blade type automotive fuses across the terminals, which also works.  I have also seen aluminum foil and thick copper wire used, but I don't recommend them unless you like electrical fires.  Good luck,

Jan