Motorcycle Repair: Assumed electrical issue with Yam. XT500G, carb tuning, orange wire

Question
Last year my XT500G (1980) was fouling plugs due to a bent valve (too much oil in the cylinder).  I replaced the valves/guides, rings, gaskets, etc.  I believe I have some outstanding carb tuning issues, but not enough to keep the bike from running.  After putting everything together, I was able to run the bike for a few minutes including some heavy acceleration (the year previous, as soon as I gassed it, the bike would die and oil would be leaking out of my exhaust)... while riding I slowed to a speed that killed the bike.   When I tried to start it again, I couldn't get a spark.  Checked the engine kill switch with a voltmeter and it seemed to be working fine.  The battery is and was dead through this process.  I haven't hooked up all the lights on the bike (mostly rear and blinker lights) but I figured that wouldn't do anything (isn't that a completely separate circuit for an enduro).  How should I approach troubleshooting this?  If it is my CDI unit gone bad, how bike specific are those units?  I have access to an XT550 1983 Yamaha uses 12V battery but uses CDI technology.  My bike is 6v battery.  Wondering if I can try the CDI unit from the other bike in mine.  That may be further down the road in my troubleshooting.  

What do you suggest I do?  Would it help to test the orange wire coming out of the CDI unit to the ignition coil to test the CDI unit, or will a short in the ground circuit negate the usefulness of that test, or will I even have the tools to test if a CDI unit is bad?  I'm somewhat mechanically inclined but by no means a mechanic.  I'm probably barking up the wrong tree with a CDI failure, but just trying to narrow my possible problems.  

I really appreciate your service.  Jason  

Answer
Hi Jason.
 This sounds like a charging/battery issue rather than a CDI problem.  CDI units generally do not go bad.

 You need to have a fully charged battery with good cells.  Test your battery with a hygrometer after you charge it.  If you have a bad battery, then that could be part (or all) of the problem.  If the battery died because it sat unattended for a few months, then it will have bad cells and needs to be replaced.

 Does your bike have a stator or a magneto?  Whichever you do have, if it is bad, then that could be the problem as well.  It should be charging the battery at 13 - 15 VDC while running.

 Reconnect all of the electrical and use a good, fully charged battery and check the power output at the battery while the engine is running.  Since you have done the engine work, I will presume that you have the repair manual.  It will have the proceedures and test specs for those possible problems.

Let me know what you find.
Good luck.
FALCON