Hi Ian,
I'm just wondering if you ever managed to get your ignition problems sorted? I'm experiencing something similar on my newly rebuilt A7ss. Due to the magneto being well and truly destroyed when the Engine blew up I've taken the opportunity to fit a Pazon Surefire in a Magneto replacement body from Paul Goff (my bike was already running 12v with a DVR2).
While the system is sparking nicely, all I can get from the bike is the occasional collosal backfire and it won't even attempt to start.
I've never set ignition timing before so I'll run through what I did to see if anyone can spot any obvious errors. I used a TDC tool from Draganfly (picture) which is marked in mm. I checked the documentation that I had and the correct advance for a Shooting Star is 3/8" BTDC (I believe that this equates to 9.5mm). With the engine in top gear and the back wheel off the ground I rotated the back wheel until the TDC tool was fully extended when screwed into the LH cylinder. I then backed the wheel off by rotating it in the opposite direction until the TDC tool had fallen by 9.5mm. I set the pazon to this using the anti-clockwise setting hole. Given that the Pazon uses a wasted spark system, it shouldn't really matter whether the cylinder was on the compression stroke or not.
I've double and indeed triple checked everything I can think of which leads me to believe that I must be overlooking something very simple.
And now I've just slipped off the kickstart and taken all the skin off my calf and I'm proper fed up