Motorcycle Repair: blown fuses, blown fuses, hi adam

Question
'82 Yamaha XJ650 Maxim
I,ve been having problems with my main fuse blowing.It only happens every once in a while,once about 3 months ago,once last week and twice today.It blew today in the middle of a ride,put in a new fuse,went down the road and it blew.Any thoughts?
                                  Adam

Answer
Hi Adam.
 Fuses blow because of overamperages in the system.  99 times out of 100 it is because of shorted or arcing wiring.  Since it is the main fuse blowing you may want to look at what, if any, new components you may have added to the bike or, since it is an old bike, the wiring harness may be starting to fail.  You are looking for a short, a burned up or bad connection, or somewhere that the wiring is arcing against the frame or engine.

Get your repair manual out and reference the wiring diagram in there.  Check everything that you can from the fuse to final ground in the main wiring, as well as to the fuses for the other circuits.  If it were in one of the other circuits then those fuses would be blowing instead.

Good luck.
FALCON