1983 Xj1100 two cylinders not firing

Hello and thanks for all the information on this board.
I bought an '83 xj1100 last fall. Got it on the road this spring and it has been a great bike. I've been browsing this board since I bought it and I understand why there are so many dedicated owners of this line.
Yesterday I was cruising and all the sudden it got really boggy. Flipped to reserve but it didn't feel like low feel was the issue. Got to a gas station and noticed 2 and 3 were cold. Unplugged 1 and 4 tried to start it up and wouldn't turn. So I figured I would change the spark plugs, before digging deeper. I get the feeling that works once I start ripping and tearing it will become more of a project.
Thanks again to all the great threads here.

 

2 & 3 not firing would suggest a problem with the ignition coil that fires those cylinders or the pick up coil that fires those cylinders. 1 & 4 work off their coil and 2 & 3 off theirs.
It could be a bad connector at the ignition coil going into the wiring loom, a bad pick up coil at the crankshaft end on the left side of the engine or a bad connection going to the igniter unit under the seat. In the worst case it could be a bad igniter unit.
I don't think it's a fuel problem though I could be wrong. If it was a fuse all four cylinders would be down. Do all the simple and easy checks before anything else.