6 Cyl missing one spark

[oldwoodboats]

My yard sale '94 evinrude 6 HP ran fine the first two short times out. But now it runs on only one cylinder; except that one in a while the other cylinder cuts in for a rev or two and quickly disappears. Any ideas before I pull the flywheel and delve into the ignition mysteries? oh yes, I did indeed check that both spark wires were fully seated.
Thanks for any ideas

[highcountry]

Not much into the newer motors, but look at the 1/2 spark thread and it might help. You either have a coil or power pack that is breaking down I think.