I have a 1987 ninja 750. i bought it and it turned on with an old battery but needed to be jumped to start. i bought a new battery . a duralast the one you add the acid in and charge. but now it wont turn on. a battery before that i added a new battery but i mixed up the terminals (pos on neg and neg on pos) did that mess up the electrical stuff or fuses or am i doing something wrong. hope to hear some help.
james is right you MUST have blown a fuse or two and a blown fuse will keep electricity from getting to any thing and everything so double check all of your fuses and uhhh do something about your terminals i am hoping the reason you mixxed them up is because they arent marked and so you should mark them so you dont take a chance of doing even more damage
If you connected a battery backwards, you hopefully just blew some fuses. Check them all. Note that there may be a main fusible link somewhere apart from the actual fuse block. If the fuses are all good, you've blown some major electrical component(s). Time to either start troubleshooting, or haul it to a shop.
Do the ignition lights come on? Will it at least turn over but not start. I think we need more details.
