1992 Evinrude 200XP no spark

This has me baffled. I had a problem with no spark a couple of weeks ago, then it sorted itself out. Last week it did the same thing again, but didn't fix itself. I tried a different power pack, no difference. I got a third pack, and installed that.. still no spark. Today I have changed out the timer base, stator, flywheel, and power pack again for known good ones, and still no spark on any of the cylinders.

I have the black/yellow kill wires disconnected at the pack, I've disconnected the main engine harness, and I'm am using a remote starter on the solenoid to crank it over. It's a fully charged battery, all the plugs are out, so it's cranking over at well past the minimum of 250 rpm. And as per the CDI troubleshooting guide, I've taken the yellow and yellow/grey wires from regulator off, to rule out a bad regulator.

What's left??

Whenever I have encountered this situation....spark comes and goes...for no real reason.....it is either starter speed, OR
and this is kind of a stretch.....the yellow /red wire coming to the starter solenoid that picks the solenoid.
That wire comes in the harness from the key switch to the solenoid, and then on to the powerpack. When it goes to +12v during the starting process, it picks the solenoid AND it signals the pack to initiate QuickStart. But, if the voltage is low on that wire at the pack, then you will have intermittent spark/no spark.

In every case a new battery fixed the issue.

Measure the voltage on that yellow/red wire (at the pack) when starting. If 10v...9.5v...9.0v in that range, etc....you will have intermittent spark problems.

It comes from an old battery that might have enough ooomph to crank the motor over, but not maintain over 10-ish volts on that yellow/red starter solenoid pick wire.

Okay, that sounds good, but the pack that I have on now doesn't use the yellow/red wire. I installed an unlimited RPM pack as my last straw, it uses a different timer base, and there is no hook up for the yellow/red. I know it works, it was on another motor that I blew up.

I got it running.. this power pack and timing base uses the purple wire to power up the pack, and with the main harness disconnected, it wasn't getting power.