Motorcycle Repair: my problem arose coming back..., rain hail, vapor lock

Question
my problem arose coming back from sturgis.the bike ran well all week in rain, hail, and driving wind. we hit major traffic west of denver. we rode the shoulder as much as possible but were forced to sit at times. we shut off the engine at times and once it didnt restart. we checked the plugs and they seemed to be fine. we removed the air cleaner and it was clean. we tried firing the engine with the cleaner off and started leading me to think it was vapor lock. we had to make a gas stop and the bike wouldnt idle. it ran fine the rest of the way, it starts up but as soon as the throttle is backed off it stalls. i changed plugs, and wires, i checked the vacume hoses and they seem to be working. the bike is a 96 sportster 883H. any suggestions would be greatly appreciated.

Answer
There are two things that might be happening. The pickup, located under the cover on the right side, is going bad or the coil is going bad. Both can be affected by heat and either one can not work when hot, but work when cold.
Good luck and happy riding
Mike