coil woes - 1969 johnson 6hp

[texas_salt]

So, not knowing the engines history, I replaced the entire ignition system, from points to boots. New coils, condensers, wires, points. Gapped .020

Today I installed the final part. The points. Still I had fragmented/no firing on thr top cylinder. Finally I decide it HAS to be the NEW coil. And it was!!!

I put in the old coil, and now its firing on both cylinders.

The issue now is, that top cylinder is misfiring a whole bunch (seeing it with a spark tester). The bottom cylinder glows beautifully at all throttle positions.

So, can misfires be a result of the old coil? When the NEW coil decided to work intermittenly, it didnt seem to misfire, much. With this old coil tho, its all over the place.

Is it a good idea to assume that I just need to swap this non-working NEW coil with another new one (and dump the old one)?

Carb was rebuilt 2 weeks ago. Its crystal clean. Fuel pump should be fine. Like I said, when the new (now not working) coil fired, it didnt seem to misfire all this much.

Thoughts iboaters?

 

[hardwater fisherman]

Did you clean the points? Even when new they need to be cleaned.

 

[F_R]

The bad coil cannot damage a good one. So forget that theory. Do a continuity check on the entire spark plug boot to coil secondary circuit (assembled). But I also agree with the previous statement concerning the points. And double check the gap while you are at it. Finally, did you properly adjust the coil to magnet air gap?

 

[Crosbyman]

sounds like a points issue.



but you can also try putting the good known coil in the bad one's position if it fails work backwards.. swap the condenser (easiest) retest then try swapping the points


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[Chinewalker]

Also, make sure you're not chasing your tail - confirm that the spark plug wire is firmly and properly seated inside the coil.

 

[texas_salt]

For future readers, it was infact the coil.

Thanks for the advice guys