Got my first bike looking for advice
 

I bought an 06 Ninja 500. The guy said it ran well, but it just needed a battery. I put one in and it started after some messing around with it. A day later it started up and i rode it. The next day it wpuldnt start, but was turning over. The next day when i tried starting it wwould not turnover at all. The battery is completely dead and will not hold a charge. Any ideas??

Are you making sure that the key is off? Pull the key to confirm that it is in the OFF position.

Welcome to KF. I have an '05 as my daily rider.

Good advice Dragone.
Then I suppose the next thing to do would be to use a circuit tester and check to see if the bike had some kind of electric load with the key in the off position if the battery was still draining overnight?

wow, did not think of that one. I will have to use my fluke voltage pocket sniffer. That would be cool to find live wires with your sniffer telling you that the ignition switch is toast. I like that thinking.

I wasn't even thinking of the ignition switch being toast, but rather one of the live wires from the battery grounding out somewhere. Either the primary stock one possibly wearing through. Or if the PO did silly stuff like me. I have two other live wires from the battery: 1) a battery tender pigtail for easy tending of the battery (have these on the KLR and quad too), and 2) a live wire up to the Vapor computer that replaced the stock gage cluster.

Certain model KLRs are known for wearing of the primary live wire from the battery to the ignition switch. Unexpected battery drain is an occasional first symptom. Blowing fuses is more obvious.

Did the PO do any interesting wiring modifications?