Charger I have is a 6 amp. Too high? Also took a reading with meter and get 12.45V. Wouldn't that be enough for horn/lights to work?

 

6A is probably not recommended. Not sure about your voltage, but I'm sure someone else knows exactly. Have you checked all your battery cable connections for corrosion or looseness?

John

 

Update, new battery and started right up. After putting meter on it and getting 12.45V, I then turned key on and checked with meter. Got 5.3V. My guess is reason it ran like it did, backfired etc upon jump starting is only enough juice for 1 cylinder (?). Anyway thanks for the help, sure I will be back for something else.

 

With the bike running at a fast idle (~1500 RPM) your battery should measure between 13.8 - 14.8 volts. If it's less than that, your charging system (stator and/or regulator) aren't working.

 

I'm guessing the 5.3 volts was without the bike running but with the ignition "on"?

That makes it sound to me like the old battery had some damaged cells and just didn't have the amperage capacity anymore. 12.45 volts resting is something like a 60% state of charge for a battery that's healthy, but if it was dropping to 5.3 volts just from having the switch in the "run" position without the engine running then the old battery was in very rough shape indeed.

As a "while you're in there" thing, you may want to consider cleaning the end of the negative cable where it attaches to the crankcase since that's a connection that seems to get dirty easily on these bikes.

 

Yes, 5.3V was without bike running, just the key on position. Thanks for tip on ground cable.