Slant won't start!!?!!?!?

Try turning the engine over by hand (tug on fan belts). If you feel 3 strong "air springs" each rev for 2 revs, that bleed down slowly, you know you have great compression. If not, try cranking it faster with a compression gage ($15 kit Harbor Freight). Don't keep pushing the pedal or you will flood it with gas (each push is a squirt). If you do flood, hold the pedal to the floor and crank to "clear flood".

Your timing light test is a good indicator that the spark is getting to the plugs. Make sure there isn't water down in the spark plug tubes to short it out though. You could also try an in-line spark tester ($4 at HF). Try spraying starter fluid down the carb throat too.