This is a points and 6volt system on a 1970's motorcycle and I couldn't get it to spark after putting the bike back together a previous owner completely stripped it down.
Maybe the regulator/rectifier or bad earth causing it, I am not an expert on this. I ran a Hot wire via the ignition on my Torana as it would drop below 7volts as the revs went up, after that fix it would it would rev past 7000rpm
