I feel really stumped. My 1986 Honda VT1100 starts on like three revs, runs perfect, then dies like someone hit the kill switch. Push the starter, it starts right up, runs perfect, then dies. Rev it to 3000, it runs great. and it might keep running. I then might be able to ride hard 50 miles, stop-n-go or highway, then pull up to a stop sign, at idle, it dies. Rinse, repeat. Always has gas in the bowls (checked by turning drain screws out). New battery, always has about 13 volts at rest measured at battery terminals, and near 14 with engine running. At higher revs, I've seen it hit 15, but seems usually to remain mid 14s. Coils primary leads, tested at harness connectors, show 2.5 ohms each (Haynes book says approx. 2 ohms is spec.) Ignition pulse generators 455 and 437. Haynes spec is 450 to 550, so one is low, but my other engine ran fine and its IPGs had like 427. Camshaft pulse generator at 630 ohms is within spec (Haynes: 570 to 690). I have recently cleaned the carbs, changed the fuel filter, the air filter was replaced a year ago and looks 95 percent spotless. I have swapped new and old fuel pumps in and out and bypassed and unbipassed the fuel pump relay. It does what it's supposed to do. I long ago removed the air vent control valve and plugged the orifices. Even with the valve gone, my idle air screws are out only 1 turn each, and very little backfire on decel. And it runs fine, pulls hard, doesn't miss, except when it just shuts off. I've also cleaned the kill switch and ignition switch, and replaced the little springs in the ignition switch. They test out like they're supposed to function. I have no kickstand switch. I replaced the clutch switch (and the similar brake light switch on the other side). The front cylinder plugs look gray and dry, the back cylinder plugs are black like that cylinder had been rich (I adjusted that carb).
I've looked for shorts in wiring, I haven't found any, probably because I recently replaced the harness with a good used one after experiencing faulty connection problems. My bike lives outside in Florida, only occasionally it gets to sleep under a pole barn. I ride daily, though, so that dries it out. What could make it shut itself off and then start just fine the next second? Can the spark units fail intermittently? Should I throw money at the pulse generators?