Portland Fever is definitely in the air! Preparations for travel to the annual gathering are underway for engine enthusiasts from Australia, Holland, the UK and across America. For those of us on the Stationary Engine Mailing List, hosted by ATIS, the Antique Tractor Internet Service, it is the best chance to meet all the folk we correspond with every day by email. Instead of trying to describe problems and solutions with engines, we can show each other! Maybe for that reason, there hasn't been a lot of in-depth discussion on the List for the past month. The questions raised have mostly been answered with a single e-mail or two, so there hasn't been much for me to pass on to the readers of GEM. However, just as so many items are tucked away in the corner of engine sheds around the world just because it looks interesting and might be useful one day, I hoard old e-mails in a similar way! The only query to the List which I felt had the basis of a worthwhile subject was about the an EK Magneto. While that in itself didn't provide a lot of information, it gave me the idea of searching through older mails to make up the definitive collection of Magneto Tips!

* I have an EK mag on an engine that appears to have been rebuilt. Everything inside looks new. Now the problem I have is a very weak spark - I can hardly feel it or see it with a spark tester. If I disconnect the wire and condenser from the inside and give it a few minutes then reconnect, I will get two good sparks then back to very weak. I have cleaned the points and tried a new condenser from a car ignition but the result is the same. Any suggestions?

I've only touched on the subject of magnetos once before in these articles, and once again I assure you that I have been most careful to use information from those who I consider to be most knowledgeable in this area, so that I can be confident of passing on the most reliable information.

* The most suspect part of an original EK is the capacitor. They just don't last this
long. If the mag looks mechanically ok, the capacitor is the first part to consider.
It's not possible to conclude a cap is good by testing it under conditions different to those in which it operates. Luckily, they're cheap enough so you can just put in a new one.

Here's a little tip that was passed on to me by Bill Young (an engine collector living in Japan). A weak area of the EK design is the movable point. It is grounded primarily through the bore in which it travels. If the bore becomes sloppy through wear, if dirt accumulates, or if you become overly enthusiastic with the oil can, resistance will be added to that part of the circuit. Minimal voltage loss in a magneto that is otherwise marginal can result in substantial degradation of the spark. The fix is to add a shunt wire from the point adjustment screw to the body of the magneto.

The next question concerns broken magnets inside the magneto.

* I finally got my upright Maytag running and discovered that the magnet is broken in half. She still wants to run. Can a guy weld and recharge those mags or I am better off to
find a replacement?

Once again, our resident experts came up with answers, of which the first part is pretty clear!

* NONONONONOONONONO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Don't weld your magnet!
It will be ruined. Several reasons. First, the heat of welding will alter the properties and make a "dead spot" in your magnet. Secondly, welding will spread apart the two halves of your magnet leaving an air gap inside.
Leave your magnet as it is and keep yours eyes open for a replacement (I doubt you will find one). Check the magnets on later Johnson Utilimotors, they MIGHT be the same. FW mags for uprights were made by Quick-Action Magneto Co. At some point, they switched to Bosch. They look similar; you might get lucky.

* Actually, unless the magnet is trying to fall off, it is probably best to leave it as it is: two pieces of a broken magnet will be as good as a whole as long as they are in contact with each other and the core and are "saturated".
If one or both pieces are in danger of coming off, then it is best to only tack weld them on each side.
Keep in mind that "HEAT" is the great destroyer of magnets, in order for a steel based magnet to be a magnet it must be very "HARD", welding will destroy the temper in the steel and weaken the magnet.
If appearance is your number one consideration, then a replacement would be best.

Now for some real gems of magneto wisdom.

* It does not matter which way the magnets are returned to the magneto.

* It is not necessary to mark the magnets.

* It is only necessary to put multiple magnets back on the magneto with all of the "like" poles together.

* Polarity should ALWAYS be checked each time with a compass; DO NOT DEPEND
ON ANY MARKINGS, they can be and many times are WRONG.

* Use your compass only for comparison. Compasses that live close to magneto chargers can and do get reversed. Check your charger first, then the magnet to make sure they are OPPOSITES.

The message about polarity of the magnets is a crucial one, as is not relying on any markings found on the magnets.

* I can't even begin to know how many times people have asked why the "NE" marking on the magnets isn't north (or north-east?) It is actually the logo of the magnet maker, "Northern Electric" I think.
Don't trust the markings!!!!!!!
Also, be sure to check your compass before charging your magnets. Mine gets repolarized about once a year if I am not careful. I NEVER use my hiking compass to charge mags!!! I might get REALLY lost someday!

* On another note, chargers will reverse also if you change way they are connected to the power source. So I don't recommend marking the poles of a charger either, check with a compass every time.
North and south are not really important, OPPOSITE is what counts.

With all this useful information about, there has to be ONE doesn't there?!

* Personally I've had good success finding "North" on my mag magnets by checking which side of the magnet had the moss growing on it. I hope that helps....

Here's another thing you may have always wondered about.

* Okay, here's a question that gnaws at my guts -- I've searched the web,asked around, and nobody has been able to answer the in black and white.

Given:
Magnets are marked N and S for the north and south poles.
The compass is marked N and S for the north and south poles.
The map is marked N and S for the north and south poles.
Observation:
When I stand in the yard with my compass, the N points north.
Problem:
Every elementary school student knows that magnets align themselves along OPPOSITE poles -- north-south, but never north-north or south-south Thus, my third grade education leads me to believe one of the following: the N on the compass is the south pole, or when I'm facing north, I'm facing the magnetic south pole of the Earth.

Question:
Which is it? Is the N on the compass the south pole, or was Peary really the first to reach the SOUTH pole?

* You've got it! Here's the way to remember:
The needle on the compass is a "North-Seeking" needle. That means the north point on the needle is actually charged south!
This also leads in to why some magnets have marked poles yet are charged opposite the marks. Sometimes that means that the person who put the initial charge in was not paying attention. Other times it may have been an instruction to the assembly tech to "put this pole on the North of the charger."
As has been said before, a compass is used as a comparative instrument, not an absolute one. After all, which way is up anyway?
Finally, now we've established the difference between North and South, there's the question of recharging magnets.

* If anyone has access to scrap electronic parts you might consider the way I made my recharger.
I made the U shaped magnetic path & wound it with about 20 turns of heavy cable (thick as my little finger). I connected this to a large capacitor (100,000 microfarads 50 volts) via a very large Thyristor. I charge the capacitor with a small 50 volt power unit via a resistor.
When the capacitor is charged I press the button to trigger the thyristor.
Any magnet across the core is magnetised & any iron nearby twitches.

* That is a capacitive discharge type of charger. That is how rare earth magnets are charged. In fact, you don't need such thick wire. You can use very thin wire, much smaller than is rated for such a large current.
The capacitor dumps a HUGE slug of current through the windings for an instant.
If you make your calculations right, then the wire won't melt. Kind of scary thinking that you could dump 200 amps through 18 gauge wire (or whatever the numbers come out to be) but that is how it is done.

* I see how you can recharge horse-shoe type magnets, but what happens if they are in a flywheel, like the Maytags, or Briggs and Stratton? Do you have to remove them from the flywheel??? Or is it possible to charge the magnets in place? Also, how do you keep a keeper on the magnets while installing them???

* Flywheel mags are usually charged with magnets in the flywheel, and it generally requires a set of specialized "Poll Pieces" to make the connection to the charger.

Horseshoe magnets require a flat bar keeper, flat bar magnets require a horseshoe shaped keeper, in either case you leave the keeper on the magnet until the magnet comes into contact with core of the assembled magneto. Mags of any type can be charged as assembled units, or the magnets can be charged separately and moved to the magneto with a keeper. Most mag guys, use both methods of charging.
Many of the old repair manuals give charging the magnetos as the last step before returning the magneto to service.


I hope this has clarified some of the mysteries of magnetos.


If you can make it to the Portland show, then be sure to stop by the ATIS Stationary Engine List area to say hello. We have a big banner to identify us, lots of national and state flags and plenty of unusual accents!

stationary-engine@atis.net

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