Other Low-Tension Magneto Parts
There have been many makers of low-tension mags. Most were quite reliable and do not need repair to this day, other than the occasional magnet recharge. I have grouped the parts together by manufacturer. Also, this page does not include generator mags, like the Motzinger Autosparker and many others. Those are covered on the Generator Mags page.
American Bosch / Bosch / Robert Bosch
Goodson
Associated / John Deere
Associated (also known as AMANCO overseas) was one of the few companies that claimed that they made everything for their engines under one roof. This was probably quite true (perhaps their mags were made in a different building). They made two versions of their low-tension mags. The first used two tall magnets with a band covering the seam. There are 4 holes in the bottom of the mag for mounting. This is an extremely reliable mag and rarely needs repair.
Their later low tension mag used a single shorter magnet and has 2 holes in the bottom for mounting. This was their most popular and was used widely on their engines as well as the John Deere type "E" engines. This design proved somewhat less than reliable over the years due to the expanding pot metal problem. But unless your magnet is cracked or you armeture lamentations are damaged, I can supply parts to fix your mag. I can supply coils, bearing plates, lead-out towers, brushes, and even complete bodies. I can also repair the armeture endplates (where the shaft connects) and also could probably make a shaft if needed. Look for gears on the Magneto Gear page.
There is no lettering of any sort on either of the two designs.
| Order number | Description | Picture | Price each |
| LT01 | Bearing plate for Associated (John Deere) rotary mags | 38.00 | |
| LT02 | Lead-out tower for Associated (John Deere) rotary mags, with brush | 22.00 | |
| LT03 | Brush for lead-out tower for Associated (John Deere) mag | 4.00 | |
| LT05 | Lead-out tower for early 4-bolt bottom mag | 18.00 | |
| ASC01 | Replacement body for Associated (John Deere) rotary mag | 165.00 |
After than Webster, I would have to guess than Sumter sold the second most low tension mags. There have been so many models that they have made that I have yet to see them all. Most of their mags were a little on the small side, and were a little weaker than I would like. Many companies offered this mag as an "improvement" over the Webster. In my opinion, Webster made a far superior mag.
To compete with Webster, Sumter made a similar mag that they called the "Plugoscillator". Like the Webster, it was a self contained unit that bolted onto where the igniter when. Sumter used their rotary mag and converted it into an oscillating mag (they are really the same thing) and made claim to have a superior oscillating mag. Webster took them and other oscillating mag makers all the way to the Supreme Court to fight the claim. Webster claimed that a rotary mag converted to oscillating use could never perform as well as a mag designed as an oscillator. The Supreme Court bought it and Sumter removed the claim from their advertising. Being an engineer myself and looking the the two systems, it was purely a marketing ploy that the uneducated court system fell for
I also have replacement bases for Sumter mags. These will replace the broken pot-metal base with a nicely cast bronze piece. No further machining is required. Inquire for details. Sumter coils are terrible at best and usually need replacing. I have seen several with their insulation completely rotted away. The new coils will give FAR superior performance.
I can also fabricate most brushes for low tension mags. Inquire for details. I will be fabricating many lead-out towers and covers this winter. Inquire for details.
| Order number | Description | Picture | Price each |
| LT20 | Replacement base for Sumter mag, models #10 & #12 | 38.00 | |
| LT21 | Replacement base for Sumter mag, model #14 | 38.00 | |
| Call or e-mail for bases for other models | |||
| expect name bands real soon | |||
| LT25 | Wire connection cover, with interal wire clip, several models, goes on the end of the mag, black plastic | 24.00 | |
| Coil rewind, most, check for model, others may be higher | 100.00 |
Wizzard magneto made a few different designs of low-tension magnetoes. These mags were probably OK in their day, but their complicated trip mechanism leaves much to be desired. One smaller style uses two magnets with a tag on top that is held in place by an annoying and overly complicated set of fingers. I hope to reproduce that tag soon, but NOT the fingers! I can also have coils rewound.
American Bosch / Bosch /
Robert Bosch
Bosch is well known for its high tension mags. In fact, Bosch didn't get into low-tension mags until probably the 30's or 40's. It turns out, that if you have a very long run (6 feet or more) between the mag and the spark plug, you get a greatly reduced spark due to the capacitance and the inductance of the spark plug wire. But the effect only has a great impact on a high voltage line, not a low voltage line. Since many of the later oil field engines had the mag many feet away from the spark plug, a low tension mag was used that drove a coil very near the spark plug. This is very common on very large engines and many of these engines are still in service today.
Some of these parts are still available from Bosch. Let me know what you need and I can check for you.
Fairbanks Morse made the "LTR" series of mags for oil field engines for the same reasons as Bosch above. Some parts are still available. Let me know what you need.
New Holland used a variety of mags on their stationary engines. Early engines used a very hot Sumter mag. The also used Webster mags and Wico EK mags at the very end of their product life. But for a while, they used a mag that had no markings on it other than a "N" and a big "New Holland" nameplate. I have never figured out for sure who made these mags, but I strongly suspect they were made by Sumter under a special contract to New Holland.
In any event, this mag is special not because it is a good or a rare mag (it is certainly rare), but because over time they have become EXTREMLY FRAGILE!!!! They were made primarily of pot metal and have suffered badly with the exploding pot metal problem. I know of 2 of these mags that were destroyed in shipping even though they were carefully packed by the most experienced people. I therefore strongly recommend that you NEVER SHIP one of these mags! They are just too fragile. If you have one that needs to be serviced, bring it to me at a show. If you can't meet me at a show, give me a call and I can hook you up with someone else who services mags at a show near you who is reputable. And make sure THEY don't ship the mag!!
As for parts, I can get coils rewound. Cliff Moyer supplies reproduction name bands.
Elkhart produced rotary low tension mags for Sparta Economy engines and probably a variety of other applications. They are a simple mag with pot metal cases and pot metal gears. The gears are usually bad. When I get a good one someday, I will have some made. I am sure I can have coils rewound for this mag.
A brutally difficult mag to repair, these mags were a complicated setup using an inductor plug and a low tension mag. They were used on the Callahan engine. I don't suggest you take this mag on to repair yourself. It is not for the beginner. When repaired properly, they are quite hot. If you need service on one of these mags, give me a call and we can work something out.
This is by no means a complete list. This merely comprises the few low tension magneto companies that I am aware of. If you have some information on other mags, I would love to get a copy of it. I hope that this list will grow over time and will eventually include some pictures.