Reduce contact-fire on Trembler Coil buzzer

[rainer]

Today I finished the re-assembly of my Lizzy.

Checking the spark firing sequence (1-2-4-3), I hand cranked slowly and watched which coil is active. Sequence is ok, but I see a relatively strong firing.

Is it possible to add a capacitor on the trembler coils directly? I mean in a way that I do not have to dig into the coil to replace the internal capacitor?

[speedytinc]

Yes. seen it done. Make sure it clears the coil box lid. My feeble memory says it can be placed out on a terminal post. Dont quote me on this. Might be worth confirm/deny. In fact, A coil wizard will be visiting . Ill ask directly.

[TRDxB2]

I am not advocating doing this but it has been done by others as a temporary fix.
http://www.mtfca.com/discus/messages/50 ... 1424318130
Doing it the right way may be easier in the long run when trying to protect an external connected capacitor to the coil posts from shorting when securing the lid. The lid is needed to keep the coils form moving and loosing their contacts. Its also important to use the capacitor matched to the coil so maybe there lies the problem. http://www.mtfca.com/discus/messages/80 ... 1248132830

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Some videos to replace the internal capacitor

• 3 part expert instructions
  https://www.youtube.com/watch?v=uhaxW3jaG0Q
  https://www.youtube.com/watch?v=br78FzWKlV8
  https://www.youtube.com/watch?v=nZH0QNwB0rM

others
https://www.youtube.com/watch?v=FyqwOVLbuek
https://www.youtube.com/watch?v=B1zT53oBFck

[rainer]

Thank you so much.

I will try without hood if contact fire will strongly reduce with externally attached capacitor.

At Chaffin's we use a 0.47 uf, 400V polypropylene capacitor with a dV/dt rating of 6000.

If it works, I think about opening my ignition coils, otherwise I let it be. Therefore I am asking for the external cap before having unnecessary work.

[JohnH]

Definitely a temporary fix, and only for an open circuit internal capacitor. If the internal capacitor is excessively leaky, then no amount of external capacitance will fix the problem. Also, if the internal capacitor is open circuit with an intermittent connection, if the connection comes good then the amount of capacitance is increased - not that it will stop the coil functioning.

[speedytinc]

Yes. seen it done. Make sure it clears the coil box lid. My feeble memory says it can be placed out on a terminal post. Dont quote me on this. Might be worth confirm/deny. In fact, A coil wizard will be visiting . Ill ask directly.

I did speak with my coil genus. Must be connected between upper & lower points. If you want to drill a hole or holes, you can in theory have 4 remotely mounted any where.