I bought and rebuilt the bike last summer, all was well and I rode it around ALL summer.
Just to yesterday. I got my bike out yesterday. I hooked my battery up, wrong at first, i hooked the negative to positive (mine arent color coded) and blew the 30A fuse. No big deal, switched a new fuse in, I found some nuts and bolts laying around in the shop (i had to grind a hex nut into a square nut to fit it in the NEGATIVE side) and I bolted the wires down to the battery the right way. BAM RAN GREAT.
I rode it for about 3 or 4 hours yesterday and only about 30 minutes today
As i left a parking lot, my bike shut off. Completely died. I waited a minute and then it re-fired but everything was REALLY dim, and it wouldn't rev, rpms just barely climbed over idol when I turned the throttle. So I immediately new it was an electrical issue (weak spark)
I took my seat off there in the parking lot and----->
MY POSITIVE BATTERY TERMINAL IS COMPLETELY MELTED
The raw metal, is melted and there is a puddle of metal where the terminal should be.
let me tell you this though. it DID NOT melt any of the wire, DID NOT melt the connector on the end of the wire, and DID NOT melt the nut and bolt holding the wire to the terminal. It looks like the nut got so hot that it melted right through the metal positive terminal.
someone tell me WTF happened? lol NOTHING is melted except the actual terminal

 

Check to see if there is anything contacting the terminals where the battery is mounted.
Something caused a dead short to ground, that by-passed the fuse(s).
If you can take and post some pics, that might help out.

Ern

 

a dead short to ground what does that mean?
Could it be the hex nut i had to grind into a square attached to the negative side? I feel like that would just make it an even better ground?

 

Something is making a connection between the positive terminal and ground (i.e. the frame of the bike, etc.). Nice pic by the way, although, I was hoping for a clue from a photograph, lol.

Ern

 

the reason why just the terminal on the battery melted is because the're usually made out of a softer metal like lead so if something like that does happen, it doesnt melt your wires, just the battery terminal