How did you retard the ignition?!
I managed to remove the pickup coil from the metal bracket that is used to hold it in place inside the flywheel cover. I then cut the bracket and re-welded it so that the 'tang' that holds the coil now holds it about 4mm further around the circumference of the flywheel in the same direction that the flywheel turns. I worked out on paper the 4mm is about 5 degree of retard. (I went for 5 degrees for no particular reason!)
I cocked up the bracket on the first attempt, the coil was to close to the trigger 'lump' on the flywheel which locked the engine up!, I had to re-cut the bracket and reweld it. I also had to grind a bit of the casing away on the inside to get the coil to fit in its new location.
It all took hours and hours, I hate working on that side of the engine, trying to hold everything in place whilst fitting the casing is a pain, the grommet for the wires never wants to locate properly and the idler gear gasket (The crappy paper one) always break, they are 8 quid each!.....More KTM crappy-ness for you, the holes in the gasket are smaller than the locating dowels which is half of the reason that the gaskets break. (I have cut a tiny slot in each dowel to allow the gasket to sit in the slot.