Popping Ignition Coils?

Hi folks I have just had my third ignition coil explode on me! I was trying to set the ignition and timing up and left the ignition on whilst doing it. I have been trying for about an hour, when the coil just popped, spewing oil all over the place. The other times, once when it was left on over night and once when sorting the wiring out, indicators and wipers etc.
The first that was left over night was an Intermotor and the others the cheap ones from Paddocks.
Could there be something wrong with the wiring? I cannot remember this happening to any previous motors Ive had, even when the ignition has been left on for a while.
I cannot imagine it being over voltage as the battery was only charged from a charger that does cut off at 12v and the engine hasnt run for more than a few minutes at a time in the 7 months Ive had her, due to rebuild.
Any help or ideas greatly appreciated.
Thanks.
Malc.

The Project in pictures

Is Doc helping you

Thor1950 said:

Is Doc helping you

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:hysterically_laughi

You appear to have fitted your coil upside down!

Turn it over and see if that makes any difference, as some the old ones used to have an air gap in the top for expansion when the coil gets warm.

Hope this helps.

surely the orientation of the coil would not make a difference and any air inside would be at the top whichever way up the coil was fixed(being lighter than oil).
The coil is obviously getting too hot, But why?
The first coil I can understand, being left switched on overnight, but the other two should not have gone after being on only an hour or so!
Could it be the cheap unbranded coils that are just crap and if I spend more on a decent make is it likely to last the course, or is there some other problem that will blow a more expensive one just the same?

uvs166 said:

surely the orientation of the coil would not make a difference and any air inside would be at the top whichever way up the coil was fixed(being lighter than oil).
The coil is obviously getting too hot, But why?
The first coil I can understand, being left switched on overnight, but the other two should not have gone after being on only an hour or so!
Could it be the cheap unbranded coils that are just crap and if I spend more on a decent make is it likely to last the course, or is there some other problem that will blow a more expensive one just the same?

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have a look here............Ignition coil is overheating what is the cause of - FixYa

Do a search and there are several good reasons. I just looked this up for you 10sec to look google is your friend, just ask

if your running a ballast coil without ballast resistor-it will burn out

fanatic said:

if your running a ballast coil without ballast resistor-it will burn out

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wonder if Pikeys 110 has a ballast resistor for his ballast :behindsofa: