New battery dead, would love some help.

[Erick]

I recently picked up a 1976 cb750 super sport and the previous owner said he had replaced the battery as of last year.  I rode the bike for about five days without problem, then the battery started getting weak when I tried to use the starter. I began to kickstart the bike, bit after a day of this it was no longer working. I went and purchased a brand new battery, assuming it was just the old one giving me the trouble.  Similar events transpired, the battery was fine and strong for a week, then the starter sounded a bit weak.  I attempted to drive the bike for a half hour straight at this point to see it the alternator would recharge the battery, needless to say it didn't.  I brought the battery back to the store and it registered 11.17 on their volt meter.  I do have a year warranty on it, so I'll assume they'll replace it if it won't take a charge.  I'd like to figure out the problem ASAP as this is the prime riding season here in Minnesota.  Any and all help would be immensely appreciated. Let me know if I can provide any other helpful information.

[sgtslag]

Download the Factory Service Manual (FSM; PDF file) off of the front page.  You need to look for the alternator/charging system troubleshooting section.  There are a few possibilities: the alternator is not working (bad brushes, rotor, wiring, etc. -- manual will tell you how to troubleshoot it to the failing part); the rectifier/regulator is not working (manual will tell you how to test it);, or you have a wiring problem somewhere between the alternator, rectifier/regulator, and the battery (manual will show you how to narrow down the location of the problem).  Cheers!

[wes]

slag is right about the manual! im figurin out my chargin system now. tryin to anyway.