i don't know if you checked your gas today for separation but i doubt it separated. E87 has anywhere between 70-87% alcohol in it. alcohol will keep the water in suspension. there is an alcohol/fuel test vial that the small engine repair guys use to test fuel. but it only tests for water and alcohol.
i too am wondering if your pick-up coil is bad. the wires will wear from the constant flexing caused by the vacuum advance. if you confirm you have no spark during a "no start" episode, pop off the dist cap but keep the wiring hooked up, turn the key on, and using a test light connected to power, touch it to the pick-up connector at the module. this will trick the module in to firing the coil.
joe
