hello,
I recently picked up a '99 cbr600 f4 and it seams to be having electrical issues. it doesn't seam to want to start. at first i thought it was the battery so i replaced the old one. when i press the ignition button, it turns over for a second then sounds like the battery dies. if i leave the key in the on position long enough the battery completely dies. the lights go out on the dash aswell as the headlight. once i do get it started by boosting it. the neutral light is on then it will occasionally turn itself off and it kills the engine. i'm assuming this is because the ecu thinks its in gear with the kickstand down.

thanks in advance for your help

 

If you think it could be the ecu thinking the bike is in gear I would look at your neutral switch. Do you have a service manual? The manual would walk you through checking the neutral switch, and if that's not the problem, would also walk you through the process of troubleshooting your issue. Hope that helps!