Ruining coils

i386

Captain
Joined
Aug 24, 2004
Messages
3,548
Is there any way possible to ruin the coils on a flywheel magneto ignition system? This is on a 20HP Chrysler 202HD (manual start).

Testing the secondary windings on mine show they're bad, but I'm having a hard time believing both coils just went bad. The engine does run by the way, just not well.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Ruining coils

I encountered that same symptoms with the coils that you are seeing when I was trouble-shooting my 1988 125HP motor. Secondary windings on all four coils showed to be open. What I discovered was that the metal connector that clips onto the spark plug is simply pierced into the side of the spark plug wire. There is no exposed center conductor. Spark plug wire is cut flush on the end. You can't see this unless you take the spark plug boot off. I had to cut the old boots off they were so hard and brittle. Anyways, once I saw this I was able to see a little bit of the center conductor when I looked at the end of the wire. Once I made good contact, I then got a reading on the secondary windiing indicating they were actually good.
 

i386

Captain
Joined
Aug 24, 2004
Messages
3,548
Re: Ruining coils

I encountered that same symptoms with the coils that you are seeing when I was trouble-shooting my 1988 125HP motor. Secondary windings on all four coils showed to be open. What I discovered was that the metal connector that clips onto the spark plug is simply pierced into the side of the spark plug wire. There is no exposed center conductor. Spark plug wire is cut flush on the end. You can't see this unless you take the spark plug boot off. I had to cut the old boots off they were so hard and brittle. Anyways, once I saw this I was able to see a little bit of the center conductor when I looked at the end of the wire. Once I made good contact, I then got a reading on the secondary windiing indicating they were actually good.

I actually followed that same path, and still got failed reading. I don't think my coils are bad though. I put a timing light on it and found out I have an intermittent spark on the top cylinder. This was after my spark tester showed a good spark on both.:rolleyes:

Maybe I need a fresh battery in my meter or another meter. Who knows? for now I'll be taking a harder look at the points and condenser on that top cylinder.

Thanks for your reply.
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: Ruining coils

Yes, that's the direction I'd go. Have you tried reversing the coils to see if the problem follows the coils?
 
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