1987 GT150 no spark #3 #6 cylinder when cranking, 2 power packs bad? or timer base?

[mrbass1986]

This motor is new to me , Model #J150GTLCUR serial number #R7572104 I bought it on a parts boat, stripped the boat, and scrapped it (cracked hull pad area), whole boat was CHEAP$$$, Motor runs ,but not good obviously, I have checked cranking spark on all cylinders, no spark on #3 and #6 when cranking, checked coils by switching leads from power packs to different coil but same spark plug no change, could I possibly have 2 bad power packs?,

How I noticed issue was when I was running the engine on muffs and hose and could get the engine to rev ok a couple times, I had the inline spark tester on number 3 cylinder and was watching the spark when revving, it worked good a couple time, then when it started missing and losing rpms ,and the spark on the cylinder #3 was missing.
I then checked cranking spark on all cylinders, and found no spark on #3 and #6 cranking, all other cylinders good spark .Both power packs are original OMC #583114,.the power pack leads are in the correct position at the coils tan/blue top cyl.1 or 2 tan center cyl. 3 or 4 and tan/green bottom cylinder 5 or 6. the timer base looks to be changed, maybe its a CDI unit, its blue colored tag part #133-3377 and the leads have the wrap like the CDI units I see in pictures. The resistance on the stator and output voltage seem to be good, 150v a/c cranking on the brown and brown/yellow leads. I took off the flywheel and looked at the outer magnets for stator none are loose and spaced properly, and center magnets all look good and are strong. keyway and key is good, timer base moves freely and no binding, have tried disconnecting the kill switch leads, no difference.
I guess my question would be what to check, dont want to fire the parts cannon and replace things that arent bad, OMC gurus SEAHORSE... ChampionMan please give my some of your thoughts

[ChampioNman]

Swap the packs and see if the problem stays with the cylinders or moves. That is indeed a CDI timer base.

[mrbass1986]

That was my next step, I didnt have time to do that last night, thanks again

[Bighare2]

Don’t forget to inspect the flywheel sensor magnet and the other six magnets for looseness and movement.

[ChampioNman]

First thing I'd do is verify TDC on #1. CDI troubleshooting guide has diagrams of the flywheel sensor magnet so you can pull the FW and verify the orientation.

[mrbass1986]

I pulled the flywheel again and checked all magnets, they are good, I cleaned up the connections on all the plugs, I verified #1 tdc with piston stop per instruction in service manual, right on the money. I then swapped the power packs port to starboard, and installed 6 inline spark checkers and now I have spark on all six cylinders, I fogged the cylinders and turned it over with starter, and with the oil in the cylinder it fired up and started for a couple seconds,I wasnt expecting that,. I think it may have been bad connections at 4 pin plugs, or 2 pin plugs or grounds , I cleaned them all. If I get a warmer day, i will hook up the water hose and run it to check the timing for base timing. Thanks for your help.

[MarKimBassTeam2021]

This was definitely a good read, short , But very informative.