How To Restore Tractor Magnetos

Neil Yerigan
Octane Press
February 2011

Models: International E4A, International F4, International H4, Fairbanks-Morse DRV2, Fairbanks-Morse X4B9, Wico C, Case 4JMA, Bosch MFR4A322, Bosch DU4, Eisemann G4

Data: Magneto repair, tractor wiring, electrical tools, starters, generators
Drawing on a lifetime of experience, Neil Yerigan's How To Restore Tractor Magnetos covers more than just magnetos. Yerigan discusses tools, testing, wiring, generators, starters- almost every topic related to the electrical system of old tractors. Eleven models of magnetos are specifically covered to provide a variety of examples. The wisdom of a true electrical expert makes How To Restore Tractor Magnetos a must-have reference for anyone repairing an antique tractor.

Yerigan combines theory with practical advice in discussing tractor electronic systems. Chapters include basic electricity, electric testing, and tractor wiring. The disassembly chapter goes into detail on the various tools needed to work on tractor magnetos. Yerigan's practical advice is particularly useful here as he describes both the dedicated equipment and how more-common tools might be used to do the same job.

Most of the book is focused on the disassembly, testing, and repair of eleven specific models of magnetos. These magnetos were chosen not only because they are common on old tractors, but as being representative of most magneto types. Even if a specific model is not covered, one of models in the book should be very similar and serve as a guide. Chapter Two provides the method for identifying and matching similar magnetos by mounting, rotation, and drive ratio.

Each magneto is analyzed in a step-by-step fashion that describes disassembly, cleaning, component testing, and re-assembly. A number of black-and-white photographs demonstrate the various parts and aid in identification. The text explains what to do, what to test for, and what might be wrong:

If resistance is about 0.3 ohm, turn the rotor until the points are open. If the resistance increases substantially, it means that the contact support plate has lost its ground connection.
- from the Wico C disassembly procedures

How To Restore Tractor Magnetos is a valuable resource for anyone working on old farm tractors. Neil Yerigan proves not only the "textbook" details of repair, but also the hints and insight of a long-time professional.

Disclosure: TractorData LLC was provided with a review copy of How To Restore Tractor Magnetos.

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