i have a 2002 cbr f4i i just bought it and i jumped the battery and it ran fine and great i sat with a volmeter on it it stays at 12-13 volts when i turn on the brights and rev it to 5000 rpm it jumps to about 13-14 volts but the minute i shut it off the battery is to dead to restart the bike i have replaced the battery and it seems like the alternator is working what could it be i need help fast i have a motorcycle course on wensday.

 

two dead batteries, but it seems possible? Check grounds and stuff. But try to charge the battery with a battery charger and see if you can load test maybe it is just taking a surface charge. maybe someone else understands the rectifier better than me, maybe it is giving volts but without amps????