Have you watched for spark across a plug gap with the plug body making earth? If you have spark, is it bright or faint?
Compression good and about even for both cylinders?
Clean pilot jet? (Technique described elsewhere.)
Too sure about the timing?
Copper plug wires? (Should be.)
Noise suppressors in plug caps? (Should not be.)
Clean slip ring?
Brushes properly seated in the pickups?
No spark leaks through cracks in pickups? (See LJ's recent post.)
Excellent plug wire connections in the pickups and plug caps?
Plugs gapped properly and not fouled? (This basic I'm sure you must have checked.)
Next time you try starting it after sitting for a couple of hours, don't tickle it. Try a couple of kicks no throttle, then half throttle. No go? Tickle until you see gas around the tickler, then a couple of kicks no throttle, half throttle, 3/4 throttle. No go? Pint of Guiness.
Richard L.