What happened to my Dyna coils??

Long story short, built bike 4 years ago, sold it, missed it, found it, bought it...back. guy barely rode it at all, not even 1000 miles, and now one of the green Dyna coils I got with the Dyna S ignition system has very weak spark, causing misfire. Motor is 78 kz1000. Both coils ohm at 3.1 or 3.2 and both are getting 12 volts. Did one just crap out? Seems like resistance would change once it was barely working or something. I ordered a new set but I still just wonder what happened?

He could have left the ignition turned on but motor not running. That has been known to melt coils with the Dyna S ignition system.
(That doesn't happen on the factory electronic ignition, but can happen with points.)

How do you know it's the coil and not the Dyna S ?

I swapped the coils and the misfire followed the coil. I have no idea how to troubleshoot the dyna s.

whitskz wrote: I swapped the coils and the misfire followed the coil. I have no idea how to troubleshoot the dyna s.

That's exactly how. If the problem follows the coil, that should be it.

Be sure the power feed to the coils is switched on through the ignition switch and not hot all the time.

I've read about Dyna coils failing before, both here and on the GS Resourses. I'm not a hater but I don't think they are of the highest quality either.

Check your H/T connections. Could be some corrosion at the coil or cap.
Steve

No corrosion, switched 12v for sure. The wiring was a pain since I "needed" it all hidden in the neck gusset. I'm betting the key got left on, he has kids and I'm sure my boy will fiddle with the key at some point too. I guess I could take it out but then I'd lose it lol.