Sparks fly when connecting new battery

Posted by Sparky36 on May 08, 2012; 3:55am
URL: http://vintage-and-classic-hondas.81.s1.nabble.com/Sparks-fly-when-connecting-new-battery-tp3970324.html

A little background:  Bought my first motorcycle, a 1978 CB 750 about a month ago.  Its a half finished cafe build that I thought would make a great learning experience not to mention a fun new hobby.  Only problem when I bought it was that the bike wouldn't run without the choke on and the battery seemed to be on its last legs.  Oh, and there is no tachometer.  Don't worry I didn't spend much.  I took off and thoroughly cleaned the carbs.  Put them back on and after a few kicks, the bike started right up.  It was able to idle with the choke off.  There was the occasional pop while it idled and after idling for around 5 minutes the rpm's dropped and the bike stalled out.  The engine was a little hotter than I would expect.  The oil level is fine.  I waited a day, started it (required starting fluid this time) and the same thing happened although it was able to idle for about 2 minutes instead of 5.  I did some reading and it sounded like the ignition coils weren't getting enough power which made me think the battery was worse off than I suspected.

Today I bought a new battery.  The bike was off.  When I tried to hook it up, sparks flew and smoke rose from the cables before I could break the connection.  Hopefully there's no damage from that.  The wiring on this bike is a mess.  I was hoping for some tips on how to go about troubleshooting and perhaps where to start.  Thanks!