Motorcycle Repair: 1982 yamaha virago 750, yamaha virago 750, battery cables

Question
I have a 1982 yamaha virago 750 that i just bought, i changed out the handlebars to 28" drag bars.  Sense then i have had all sorts of problems.  I only get power from the battery sometimes, when i do it will crank fine, but then it will back fire on the front cylinder or cause the front cylinder to go out completely.  Also when the cylinder is misfiring the tach goes crazy and it will barely run.  I am assuming i screwed something up in the electrical system but cant figure out what i did, all of the connections are good but i dont even know where to start looking let me know if you have any answers

Answer
Jason,

other than making sure the battery cables
are tight, connector on the ignition
module is clean and fuses are tight,
it sounds like a ignition module acting
up. Check here for solutions and symptoms
of this problem:
http://members.aol.com/ddenowh/TCI/symptoms.htm
http://members.aol.com/ddenowh/TCI/