Hi John
If it is the ignition unit then there is nothing you can do other than replace it at vast expense.
Ok this is how you get at it, remove the plug and the 3 nuts which hold the pull start mechanism. Remove the 2 srews holding the other part of the pull mechanism to the flywheel. Then remove the engine cover. Undo the large nut in the middle of the flywhell remember its a left hand thread so rotate it clockwise to undo. I use a socket and ratchet, a sharp tap on the ratchet should free it. Using a soft rubber hammer hit the flywheel away from the engine rotate a bit a and hit it again keep doing this till it jars free. Slide the flywheel off the crankshaft and you will then see the electronic stator held on with 2 screws.
Terry, July 2008