I’ve been tinkering with this bike for awhile. Followed some power back. Checking volts and seems okay. Some things have me puzzled. 
there are some wire terminals that are not connected. 
battery is fine and lights and things work. Horn, and so on. Just no spark. I’ve taken the plug out and placed on the head. Replaced with a new plug. Also cut back the plug wire and re booted. Checked my coil volt and sanded all my grounding points. Idk what to do. 
Look at the pics of these wires and lmk what you think I can try. 

1. pic:  what I think is the rectifier, next to the coil. 
2. pic: white terminal just hanging out. No other end near. 
3. pic: black wire.. just hanging out. Seems to be coming out of the flywheel -4 wire harness. 

 Mike, from near Salisbury, UK.

This doesn't make a massive difference, but what it looks like you have is a 1973 RT3 - look up your engine/frame number in the VIN tables in the Tech Library (see top toolbar) to confirm.

Yes to all three of your photo observations and leave those white and black wires alone!

If you haven't done so already, clean the faces of the points.

RT325 or MarkT will tell you how to do it, but you can run the engine using one wire to the magneto area.

The headlight only works with the engine running and the key in position two. Make sure that you fit a 6v regulator.

Hi & Welcome from NZ.
Yep as GR8 says above give points a clean!!.
Black wire hanging out is just tapped off the mag black that ends up at the coil via the loom & switch so don't ground that.
It's-i believe-a points checking wire so you can easily hook an ohm meter on low to see if points are contacting--making & breaking by moving the flywheel forward & back an inch over the opening-closing point.
Just proves they're contacting but doesn't tell you if the source coil is any good.
But they never fail [brave words] or hardly ever. Hope scratching the points is enough to wake it up.
White wire--i think?--is just a higher rate of charge to the battery during daytime running.
Battery is 'not required' to run it but without it soaking up the charge the lights could blow at revs--not many revs either as did that on my 125 accidentally, not thinking.
As Gr8uncleal say above you could run the black [from end of mag loom] direct to the coil. Be sure that the throttle is shutting off though as no easy way to stop it in a panic.
Just scratch the points first before unhooking anything & i bet she goes. But if you don't have the 'correct' flywheel puller i'd try a sandpaper stick like for doing fingernails. Not sure if they come in different grits but i'd go coarse as will only last a few wipes. I just fold some emery tape & squash the fold with pliers so no fold lump--sort of. Talking going in through the slot without removing the flywheel.
Here's a link to a puller 27mm lefthand thread i found randomly googling which comes back to this forum haha as it happens. Heaps out there & cheap too. Fit multiple brands of bikes.www.amazon.com/Motion-Pro-08-0026-Flywhe...ef_=as_li_ss_tl&th=1
Sorry i've turned it into an essay. Bad habit lol. I had one of those same year & color, actually think mine was "73. Bought it at 900 miles or Kilometers as a front end crash job, around town accident, folded forks plus frame downtubes.

Thanks! I did put a bolt meter on those wires coming out. (The black one). And I did get a super small amount like 0.04v every kick. I got a buddy coming over. We will try and clean the points with the “stick”. If not I’ll grab the puller and see what I can do. Thanks!!

Thanks again! But now that I remember I think I tried grounding that black wire. If I fried somthing what would have it ruined? I still have a tiny amount of volts on the black wire, but I did try grounding it when I first got the bike awhile ago.. thinking hey here’s a loose ground but didn’t help so I took it off.

I also did ohm the black wire this morning and it’s read a steady .6 so is that a good sign I didn’t fry anything? 

No, you wouldn't have done any damage, but you definitely wouldn't get a spark with that black grounded.

The white is only used if you are getting insufficient charge via the green and/or green/red wires.

No you won't fry anything, only kill the spark while grounded--you only became a kill switch effectively while grounded.
Now i'm not sure on what volts to expect kicking over, but go back there with ignition on if its all still connected or if the mag loom is disconnected that's good & connect the meter to the black & to earth & eyeball the points opening--just moving that is. Then watch the meter & see if you get a variation. My old analogue meter tells lies but gives me a definite variation which is what 'i'm' looking for verifying contact & no contact. I think it's member MarkT who's a Wizard at this stuff so hang about. But think he says the meter [including a digital meter] should show zero with points closed & about 2ohms i'm guessing' with points open. Be aware that you need to move slowly & not much to get open then back to closed. If you move fast or far i think voltage, even though not much voltage, will confuse the issue, or really confuse the ohms scale for sure.

Found a couple of videos showing how i do it points checking. Hope they play. Ignore my meter reading but just go by the obvious movement. Call the lowest reading zero even though stops at one i think.

redirect.viglink.com/?format=go&jsonp=vg...shorts%2FqVm-uhxIAT4
redirect.viglink.com/?format=go&jsonp=vg...shorts%2Fpf2lPN8x_YI

So this is what I got. I have no power from either of the four wires going down to the mag. I ohm’ed every wire on this bike. Every thing is good. No breaks.. I checked for volts at the switch. I have power to it. And then turn the key. Once. Brown is the only with power, turn again 2nd position. Red, brown, and blue have power. And I suppose to have power on the yellow down to the mag? I cleaned up the ign points and re assembled checked my powers.. what do I need to do? Bad switch? 

Getting out of my depth but my videos are purely resistance on ohms & nothing more.
You won't have dc power down the yellow as that's ac coming up when running for the headlight.
Not sure why you would have a DC connection between red, brown, & blue out of the switch as blue is 'usually' ac to the instruments & in my country ac to the tail light.
So i'm guess--lots of guessing--that your dc blue is US spec DC powered tail light.
I'd better bail out here before i confuse things.
I might've said just run the mag black straight to the coil as that's all you need to run the spark side.
So that way you're eliminating the rest of the loom & switch etc.
But yep clean switch contacts seeing ya in there. & if you lift the plate assembly out just note its orientation incase the drive square --not square, is offset. Something like that.