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Old 30-10-10, 02:53 PM   #31
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Originally Posted by jemglen View Post
Well, I just provided the tip, I don't pretend to know why it works! :confused:

It was given to me by a chap whose Ebay name is Moggiedude, I believe some of you here have had dealings with him?

Very nice chap, knowledgeable about engines and has a really nice collection. A real hands-on engineer as well. He was going to part-ex my ML for a reverse rotation Hovis (a common enough period swap on Lister As) but suggested I tried the reverse spin trick first.

Apparently, if it works, it works (though of course, yes, at some point in the future it will break down again, but then that's true of any mag) and the problem's solved.

My take on this is: if it's simply putting off the inevitable...well, at least you know the mag is not beyond reasonable repair.

Had dealings with M,D some years back about an engine bought off ebay, make sure you check carefully for frost damage or bad repairs!!
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Old 30-10-10, 03:27 PM   #32
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Originally Posted by Stevengine View Post
Had dealings with M,D some years back about an engine bought off ebay, make sure you check carefully for frost damage or bad repairs!!
and non return valves without the ball bearing in!!!!
Fowler 1PA,Petter W1H,Stuart P4,Villiers WX11, Single flywheel Lister A, 1931 & 1929 Shafty D's,1929 Bruston D,Wolseley WD2,Superbloc 3hp,Conord F2,1943 Fairbanks ZD,Lister Butter Churn,Brackett pump,Maroilles butter churn, D & F twin pump
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Old 17-11-10, 07:26 PM   #33
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I also had experience of M D's parts, My ruston exhaust had a repair that was not declared in the listing.
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Old 03-12-10, 09:19 AM   #34
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In the past three years I have probably worked on around 150 magnetos and rewound about 30 -40 (another 30 or so needed winding but people did not want to spend the ) , A simple Resistance test followed by a spark gap test is all i find is required to fettle out the bad from the good , if the Resistance comes back good and it will jump the required gap i send it on its way , however this still does not mean the coil is going to last for more than five minuets.

If you can rejuvenate the magneto from spinning it on drill that means there was little wrong with the coil in the first place , I cant see how it replaces magnetism to charge a magnet you must pass the point of saturation and to do that you need far more than a little stray flux being generated by spinning it . I think this has more to do with some sort of cleaning action on the points or earthing bushes , i would not recommend it !

People will always do what the believe works but this normally is closely linked to what hits the pocket the least also , If i magneto fails the simple coil checks it needs rewinding !!!!!!!!!!!!!!!!!
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Old 11-12-10, 10:24 AM   #35
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As posted elsewhere:

"Magneto Fundamentals", published by Fairbanks-Morse:

The Wico service Manual for the EK Magneto:

The Wico service and parts Manual for the Series A Magneto:
or also carries those articles/manuals.

Note that there are no navigation links to access the main menu in those last three url's.

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Old 14-12-15, 11:44 AM   #36
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Default Wico Type A magneto's

It has been interesting reading through this thread ,when Wico magneto's were mentioned I became more so . Perhaps some one may offer a comment on the following..........I am fitting a Wico type A impulse magneto to a side shaft oil engine , I am ashamed that it has come to this but to retain my sanity it has to be done . However my problem is that in chain driving the magneto from the side shaft with a 1.1 ratio after starting the impulse will not throw out unless a high speed is set. To have the lower speed of course there is a continual impulse .......mechanicaly not good for the magneto coupling ,premature wear on the pawl and stop pin. I have thought about this and believe that if I either make a new pawl of a lighter weight or reduce the weight of a spare pawl it will throw out at a lower rpm . You may suggest that I drive the magneto with a 2.1 ratio . I have tried this and still the speed is not sufficient to throw out the pawl . I would welcome any opinions , thank you.
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Old 14-12-15, 02:00 PM   #37
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If the magneto has a good strong spark you can remove the pawl (and other bits) and thus immobilise the impulse.

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Old 14-12-15, 06:40 PM   #38
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I've just read through this thread and would like to say that 1. I regularly test, condensor/capacitors with a digital Multimeter, fitted with a capacitor test, to check on their condition on motors that wont start or run.
2. If you spin a magneto fast enough it will eventually produce a spark if the coil is good but this only proves the magnets need re magnetising but because our magneto's run slow they will never work properly unless they are 100% perfect, that the whole purpose of an impulse mag to momentarily spin it faster to over come the speed of the idiot on the handle.
In the long term getting a magneto refurbished correctly will save you a lot of time and heartache and actually end up cheaper.

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Old 14-12-15, 11:04 PM   #39
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To quote a certain 60's SciFi TV show character: "Ye cannae change the laws of physics"!

If a magneto coil winding is broken, the only spinning that will get it working properly again is when a suitably experienced and equipped person is rewinding it!
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