(quoted from post at 11:35:53 06/14/16) Silver is the best conductor; Copper is not far behind. Carbon on the other hand has quite a resistance. Infact, most of the resistors used in electronics are carbon. So, if you carbon wires on a magneto, then you either get lower voltage across the plug gap or you need to produce a higher voltage to keep the same voltage jumping the gap. Hence, an electronic ignition system that puts out a much higher voltage (like in a modern car).
Most magneto engines are usually hand start, and an impusle was installed to 1). provide safety from kick-back and 2). to snap the magneto to aid in starting. If you add resistance to the system, such as use carbon wires, then you are shooting yourself in the foot. Moreover, a lot of magnetos, such as the F-4 or E4A use carbon brushes (and introducing resistance to the circuit).
Why do you need a resistor in an ignition system?
The same reason how magnetos work; they use the collapsing of a magnetic field to induce the flow of electrons, this process of the electrons flowing through the circuit in turn induces an Elector Motive Pulse (or EMF) disrupting any radio frequency in the local area; like listening to AM radio during a Lightening storm. To prevent this interference with the radio signals, by adding a resistance to the circuit, you in effectively drop the high spike in the pulse, kinda like retarding the spark. Moreover, using a resistance in the circuit helps the lifespan of the coil of a HEI system.
Regular distributors have advances in timing of a range more than that of magnetos and thus will give a better power range of the motor.
If you ever see a sparkplug with a R on it, such as a Rj8, that means the plug has an internal resistance built in. They are the fix for systems with copper wires such as Briggs & Stratton engines on riding mowers so that you could listen to the radio.
In short; Use copper wires with magnetos; carbon with electronic.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy