First off thanks for the suggestions! Back to share what I found:
- Front cylinder spark plug cable was loosely connected on the coil side. The terminal was broken and rusted. New cables on order. Ignition coil's primary and secondary ohms were to spec.
- Rear intake manifold seal leaking. Possibly front too. New Genuine James intake seals 26995-97-X on order.
- Old oil was Mobile 1 Synthetic V-Twin 20w50, I replaced it a few days ago with Motul 7100 Synthetic 20w50. The transmission oil magnetic plug had attracted as much metal flecks as it could feasibly hold. The engine oil mag plug had none.
I cleaned up and reshaped the cable's coil terminal hoping it would work. The first leg of the subsequent ride finally felt great; no misfiring, good throttle response, and the AFV climbed from 69% to 84%. Then on the way home it was back to it's poor self, the cable must have shook free.
Next week I'm taking it to a shop for a leak-down test, compression test, and new IridiumIX spark plugs. Actually the intake seal leak is new info so I may have to reschedule. I'll probably pay a shop to replace them... I've watched videos of it and taking out the intake manifold seems like a real pain, especially with no garage or allens that can reach the manifold flange bolts.
