Hoping to get this old LT2 running.  Correct me but I believe the BLACK wire coming from magneto if hooked up to coil should be all I need to get spark??
Tried that but not spark.
So tried hooking up the Green with Red strip long with with the black and I get spark.  Won't event try to run.
Bike will be used to run around yard with no lights whatsoever so I should be OK without battery??
Thanks for your help.

Yep black wire is the one. Interesting you tried a lighting or charging coil wire. I did that once & had it running but sounds like you did it without unhooking tha black so feeding back to the ignition source, unless 'that' source is open circuit stuffed in which case i could see it'd 'sort of work'. In my case i cut the source coil wire at the condenser or in there somewhere to isolate it. Then used the lowest output charge wire or the points went like an arc welder. Anyway--not recommending any of that. Give the points a scratch & check they're opening & closing before getting too carried away. Source coil on those have a very low resistance like possibly 2 ohms or less.
Ok, i found my LT3 workshop service data. Ignition Source says 2.1ohms. So looks like green is lowest resistance @ 0.31ohms. Green/Red 0.58ohms. Yellow @ 0.60ohms. But that blows my theory out of the water as thought the lighting had way more resistance than the source. Probably best to ignore what i said haha, but i did have a 100 running ok--just not sure for how long as never saw it again. Farm early "72 AG100 Yamy. By the way--i connected my green in with the black at the plug coil so it fed back down & as i said--had the source cut off, so black just ended at the condenser/points.

Thanks for reply.  Got it to run.