Motor sounds rough, but not all the time...

[fmt2bx]

Might be a trigger issue. Here is a video I saw the other day. I thought that the trigger would either worked or not. Well it seems like the trigger might also give false info to the packs as well . Not sure if this is good info or not and hopefully others , more competent posters, can help.
good luck.

Quick update:





I was curious and ran this test with all cylinders marked at dead center and I am getting a good reading with the timing light. I took a video but it was too bright to capture it well on camera. Actually the film doesn't even show the makings.
I understand the principle of the test but I am not sure that a bad reading means necessarily bad trigger. Could it be a bad pack firing to 2 coils at once? bad magnets perhaps?

 

[jerryjerry05]

Try swapping the packs?
​Try swapping the coils?

 

[tommarvin]

Keep testing, doesn't cost a lot to test, until you find it,because ignition parts are very expensive, you don't want to guess and start throwing money at it.

 

[iwaterdave]

Try swapping the packs?
​Try swapping the coils?

I did change out a coil pack after noticing no spark in the bottom cylinder. And still no spark but have spark in all other cylinders. So I swapped out the pack that controls the bottom two packs to a spare I had. Then the unspeakable happened. No miss during motor running. Possibly it was just that or possibly it was a combo of the fuel delivery and that. But I had just finished replacing the gaskets and cleaning all the fuel delivery ports. Times on the water and runs great! Does die a bit in gear idling forward or reverse but that's a huge step from where I was.
Thanks everyone for help with this.

 

[jerryjerry05]

Check the RPMS with a good tach.
​The one in the boat can be off.
750-800 in gear, motor warm.

Glad it's better

 

[fmt2bx]

That's great news! As Jerry05 says, check RPM.
Is thermostat in good shape? A good functioning thermostat helps with idle.

Glad you back on the water!!

 

[tommarvin]

Good for you, turn the idle screw till she idles in gear.
Like fmt2bx said above, stat is everything for warm up. Lots of people take them out and leave them out for some reason.