Spark on neg battery cable when starting

I'm guessing this isn't normal? lol It runs fine after that but when I crank it I can see some sparks at the battery on the negative cable.

 

Errr. i have to ask....are the cables tightly bolted on?

 

It's not normal. Everything needs to be clean and tight, no sparks.

If it loses contact while the bike is running you can potentially damage electronic components.

 

That's good to know, Thanks. and yea both cables are tight. I cleaned them up yesterday.

Does this generally mean there is power wire being grounded somewhere? or could it be a fuse/connection problem with the ignition?

 

Is the ground cable attached tightly to the engine?

The only reason i can think of for spark at the negative terminal is that you've got 12V right next to it that's arcing to ground (battery terminal). A hot wire grounded anywhere else is going to spark or heat up where it's being grounded, not at the end of the ground (battery terminal)

Is part of the harness running by the terminal? Is the insulation good? If it isn't, and it's the main (red) wire that's arcing, you're bypassing the fuse and could cause some real harm.

 

if the connection is clean and tight it's not possible. could it be the terminal to wire connection? the wire could be corroded or the crimp not tight.
after a ride, does it feel warm?

 

also check for a crack in the battery case near the terminal. Doesn't happen often, but I've seen it before.

 

OK im going to double check the connection tomorrow along with any hot wires that may be grounding.

Also, power would randomly cut off. out of nowhere, the lights would all turn off, wouldn't crank. Then I jiggle some wires by the battery and it would light back up and start again. (that's the point in which I sanded the positive cable and re-wrapped it. I don't know if it is still doing this. Ill try again tomorrow)

 

+1
re-do the terminal - maybe solder it ??