I bought  1076 DT 175 with no spark. Replaced points, condenser, set timing, new coil, wire, plug,disconnected the ignition and kill switch, new rectifier, magnets are strong, no rust on the flywheel or coils, no broken, frayed wires, cleaned the grounds and connectors, checked all other wires and they seem OK.  I can light up my test light when I connect it to the black wire from the stator. I plug in the coil - no spark   BUT when I plug in the coil and test the black wire from the stator I no longer have power coming out. I disconnect the coil and check the stator wire test it I have power again. Any thoughts? Thank you in advance.

Ohm reading at points stator wire with ignition coil disconnected...  Points open reading?  Points closed reading?

Several reports of bad "new" ignition coils.  Original ignition coils rarely go bad and some have reported spark returns when they install the old coil. 

Greetings from Tennessee. 

Welcome from NZ. When you set the timing how did you determine points just cracking, by meter or eye.
Could the condenser wire be shorted with a bit much solder. Just things i've done before.
So condenser plus source coil plus points all meet up somewhere? before heading off to the plug coil.
Plug coil earthed--should be if on its old frame mounting.
Using an old style ohms meter you should get an obvious small variation between just open & just closed--very small flywheel movement forward & back over that point.
It is possible the source coil is faulty. How does it look physically.
If all else fails i could tell you how to test using the lowest output lighting coil wire just to check for spark but won't get into that now & confuse things.
Somewhere up here i put a video of testing on my 125/175. Mine is a runner but just tested it 'because'.
I'll go find it or link the page might be easiest.
If its a bit hard to follow my videos just leave it for now.
 

Ok, not the video i was looking for but is one of mine showing open & closed but my meter is faulty & imagine it goes back to zero then move to a bit past 1ohm, whatever, obvious difference.
www.youtube.com/shorts/qVm-uhxIAT4?feature=share
Here's one kicking over disconnected from the plug coil
youtube.com/shorts/MyJ_KtM3DwY
Here's another now connected to the plug coil

I'm tired tonight trying to sort this but looks about 15AC volts with a good kick through compression & NOT connected to the plug coil . That's the link video.
Live video goes to about 7AC volts connected up top so pushing into the plug coil.
I have a running one somewhere but connected to my peak AC meter but not necessary at this stage.
Alright i just found & played it--was a while ago--& sounds like i say its on the 500 volt scale "Peak Volts that is" so half on an ordinary meter.
I can just see its set on 500 volts. It goes to 100 with a rev so 50 on a normal meter. Just tucked in with the wire at the coil from the points
Confused everyone? haha.. I haven't even got going yet.