Ok, we are down to two or three possibilities. Spark box or dizzy or coil. There is no igniter in the dizzy, just a reluctor, which is an alternating current generator. The spark box see's the a/c voltage go from + to - (or vice versa) and triggers a spark by disconnecting the coil path to ground. Using an a/c voltmeter connected to the dizzy harness connector, crank the motor and see if you see voltage on the meter, going from + to -. If not, pull the dizzy and take it apart and clean all the connectors. Check the fine wire coil around the shaft with an ohmeter per the fsm for continuity. If you take out the two screws the D shaped piece will come out so you can get at those connections.

Test the coil. Using a jumper wire from battery to coil +, and another jumper from coil- to ground, holding the coil wire about 1/4" from a good ground, make and break the jumper connection from coil- to ground. The coil wire should make a hot spark. If not, the coil is bad.

There is not a good test for the spark box. Swap with a known good one to test. The only test I know is to put a voltmeter or test light on the wire from spark box to coil -, unconnected from the coil. Crank the motor, and you should see the voltage drop as the spark box breaks the coil path to ground.

Do these tests and report back.