1984 evinrude 150 with intermittent spark

This has been a real pain here is the run down.

I have a 1984 evinrude 150 that has a no/intermittent spark failure.

Failure acures on both heads. no fire on either side.

What I have done.

I have isolated the engine buy disconecting the red wire harness plug, and used a remote to crank. (no spark)
this eliminates the kill/key

I have checked all plugs and wires. good!
I have done a visuale inspection of the wires and weather packs, all appears good.

Tests I have ran so far (all have passes on both sides)

charge coils resistance check......good

sensor coil resistance........good

The funny thing is the engine will create spark some times be it a few arks or so........ then dead again.
I am using a spark test with it set around 7/16" when it dose hit it is a very strong blue arck.

got any ideas y'all.....

Re: 1984 evinrude 150 with intermittent spark

anyone..........any ideas........

Re: 1984 evinrude 150 with intermittent spark

Disconnecting the red plug only eliminates the kill circuit to that point, it can still have a short from there to the pack. Don't know about your pack design but if you can unplug the kill wire at the pack thats another test to try.

Is it cranking at least 300 rpm?
If not it will not generate enough juice for ignition.