On mine right behind the coil a flasher unit is bolted, it also shows a flasher unit in the wiring diagram, there are two brown wires and a black wire coming out of the loom when I connect the black wire I’ll lose all spark.

Just as an experiment, unplug that indicator relay black wire and find a length of wire so that you can attach it directly to the frame. If everything then works ok, it will confirm that the black that you originally connected it to is actually for ignition testing, and not an earth wire. 

A continuity test shows all the black cables are connected, the cable coming out of the flasher is also connected to the outer shell of the flasher, so when it’s connected to the frame it’s grounded anyway, which makes it kinda strange


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So the indicators should work anyway, without the black wire from the relay being connected? Just disconnect it and get your spark back. 

To recap, my thinking (and adguy's) is that it might be an earth wire is killing your spark. Alternatively, your bike might not have the black ignition testing wire that other models have, and we could be on a wild goose chase!

Continuity test will show the ignition "test wire", if that's what you have, as a ground.

You would be several million down the list of people who have been fooled by a "continuity test" on the points magneto wire... if such a list were kept.

So why not try using a jumper wire to ground?

That does make sense mate, like why connect a ground when it’s already bolted to the frame, it’s just there’s 2 brown wires and a black wire that all connect so nicely to it lol

People here are just trying to help. 

You are free to ignore the advice and suggestions...  and you're free to continue to assume the black wire is a "ground" when by your description of location and of the spark quitting when connected to the flasher it appears to some of us to be a black wire that is part of the ignition circuit. 

You have the huge advantage of "being there" and seeing and experiencing what is going on...  you've been told a "continuity test" will not distinguish a magneto ignition wire from a true ground...  so hopefully you'll figure it out, whatever it turns out to be. 



 

I’ve tried posting a picture but it won’t work, with the flasher unit connected but disconnected from the frame the bike starts! Connecting it then kills it, so somethings up, but progress is being made.

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What are you connecting the black wire from the flasher to?