HarleyTechTalk

Anyone know the difference between condensers for mag ignition and battery ignition?

Does a mag condenser have a lower microfarad value?

Condenser size is related to the coil whiplash coefficient.   

The condenser is not needed to run, it is there to save the points.

The wrong size condenser will usually be evidenced by deposits on the point contacts on one side or the other.

The condenser (or more correctly, discharge capacitor) is there to provide an AC path to ground when the points open. If the condenser is bad, or not there, when the points open and the coil field collapses, it will discharge across the points. Yes, it will burn out the points in short order, but it also adds a resistive path (i.e. through air, meg-ohms) that the electricity has to pass through. This results in a weak, mis-timed spark at the plug. So yes, it may run for a while, but not very well.

To answer the OP's question, I don't know the capacitance between battery ignition and magneto, but keep in mind they operate in two different low voltage circuits. Battery ignition is 12V (or 6V) based, whereas the primary side of the is higher, in fact can be much higher depending how fast the motor is spinning. So I would imagine the condenser for magneto needs higher voltage rating.

Battery ignition: P/N 32726-30A
Magneto: P/N 29534-55A

-JW

Quote from: Burnout on August 05, 2020, 09:40:40 AM
Condenser size is related to the coil whiplash coefficient.   

The condenser is not needed to run, it is there to save the points.

The wrong size condenser will usually be evidenced by deposits on the point contacts on one side or the other.

Try running yer Shovelhead or Ironhead without a condenser....
the Miss and refusal to pick up RPM is a sure sign of a bad capaciter/condenser
Theory is great... experience is Better

Differences between Battery/points, and Magneto as far a Condenser???  Casn't say but Betting in Practice there would be very little [Zero] difference in Running.

That may be true, but being an engineer myself, engineers usually do things for a reason. For example, they did not carry the same condenser over from magneto to battery ignition. Why you suppose that is? I have my own suspicion, stated above. High voltage capacitors cost more than low voltage capacitors. The mag condenser will probably work fine on batt ignition, not sure the other way around would work out so well. But then, I have never done it so who knows? And why bother trying?

-JW

Quote from: JW113 on August 07, 2020, 09:04:37 AM
That may be true, but being an engineer myself, engineers usually do things for a reason. For example, they did not carry the same condenser over from magneto to battery ignition. Why you suppose that is? I have my own suspicion, stated above. High voltage capacitors cost more than low voltage capacitors. The mag condenser will probably work fine on batt ignition, not sure the other way around would work out so well. But then, I have never done it so who knows? And why bother trying?

-JW

Having been a Tech, working closely with Product Development, with Many Engineers... you know I can Answer that Question!!!!!