did you try disconnecting the shift interrupt switch ?
sometimes they become sticky.
Wish I could help. I'm normally good with automotive electrical problems but without a schematic I'm lost on boats.
Electrical gremlins can really bite you in the butt. I'm dealing with a couple on my brit bike. thankfully it's not a Lucas (lord of darkness) ignition of the old Triumphs
Max, sorry to hear your still having spark problems. Have you tried switching the CD modules between 1 and 3 to 2 and 4 and see if the problem follows? Then its a matter of just replacing the offending CD modules.
Anyway, I'm sure you will find the problem. Keep at it and eventually you will uncover the problem. Also see if you can isolate the entire motor from the harness, and run with just a few jumpers wires to see if the motor will start and run. Then you will know if its the motor electronics or the wire harness/ignition switch.
If any stray voltage gets to the black/yellow stripe kill switch wire you can count on the power pack going south in 2 seconds.
The internal diodes fry and that screws up the firing.
volatge can get to the kill wire at the ignition switch, make sure its not twisting in the dash bezel. Pinched wires etc.
Find the source of the stray volatge first, then retry the engine, if its still no good on one side you probably need a new PP.
Hey Max, I'm sorry to hear of your plightIs the spark weak on the wire, or at the plug?, are there any grounds wires near the coils that you need to clean?
If it were my engine, I'd get jiggy with it, and I would be pulling the plug wire out of the bad coil, & replacing it to begin with,,, whatever that takes!Besides, you'd then be able to test them to see if they were broken or corroded somewhere? Copper wire doesn't last forever, esp. around salt water.