Hello from across the pond and all good wishes for 2006 to all the austin collectors. I am right in the middle of the restoration of my 1927 austin seven chummy. I am working on the magneto at the moment and having trouble getting a consistant spark. Sometimes I have a spark that will jump 1/2 inch and then nothing at all. I have checked everything very thoroughly and everything is in good condition except I am not sure how to test the coil. I would appreciate information on the coil ratings and if anyone has a testing proceedure or other useful information on the magneto. The magneto I have is a B.L.I.C. and the number on it is 59580. Thank You

Hi Brian, I use an expert who lives near to me on the south coast to "Do" my magnetos. I will ring him and pose your questions and let you know. He has no internet acess. mac

Many thanks Mac, appreciate any helpful advise you can pass along. Brian.

I have spoken to Tony. As I expected,he says you must set it up to run consistantly. That is, set it up to driven by a lathe or similar. "Flicking" won't work as a proper test. We are assuming you are holding the lead and allowing it to strike earth. that's O.K. but the best test is to use 4 plugs. you remove little earth bar ( i cant think what else to call it)so you have just the centre electrode exposed. The spark should jump from the centre to the edge. He says that even a poor mag will jump the 18/20 thou gap on a normal plug.,so this is a definative test.With regard to the coil. IT may have been rewound, so do these tests first. If it appears it has not then you are on borrowed time. Have it rewound. let us know how you get on and will answer further questions. Mac

Hello Brian,
In respect to your endeavours to ensure that your Austin Seven Maggie is in good fettle, may I offer the following comments.

Firstly can I say that I have had absolutely no experience with BLIC Magnetos, but have had a fair experience with Lucas, Bosch and a number of other types.

As I understand the situation the BLIC fitted to the Austin Sevens is a rotating magnet type, which means that your coils do not have to withstand the indignity of being spun around at half engine speed.

That said though, you are dealing with a piece of equipment which is somewhere in the vicinity of 80 years of age.The coils need to be perfectly intact, free of partial shorts and breadowns if they are to produce the High Tension of 10,000 or so volts required for a good spark. The coils are almost certainly insulated with a shellac type varnish, albeit baked and maybe assisted by cotton, silk or other insulation.

The problem with shellac is that it is based on the natuaral secretions of the "Lac" beetle and is an organic material. It is generally accepted that it naturally decomposes and fails after something like 60 years. Other chemical reactions, due even to the moisture which was on the hands of the original assemblers in the factory, atmospeheric moisture, other pervading grot and grime etc over the years, also means that the very fine wires involved can, and most probably are, subject to varying degrees of corrosion.

It is also a fact that the strength of the actual magnetism of the unit will have depleted over the years.

Many "tired" magnetos are hard to coax a good spark out at low (starting) speeds, may perform tolerably at mid speeds and become erratic when called upon to dabce at high engine speeds.

While it may be possible that you will be lucky enough to coax the magneto into reasonable service by your own efforts, if I were contempating the restoration of a car so fitted, I would try and budget into my overall restoration plan the complete refurbishment of the magneto, including a new coil using "formvar" or similar modern material for the insulation on the windings, a proper checkout of the bearings etc and finally a healthy remagnetising.

The condenser, which I think is reasonably accessible on the BLIC (it is on most other rotating magnet types anyway) is also a candidate for leakage and other woes in the face of the passing years, although modern units are readily available as replacements.

The only catch in all the above is that firstly it costs, and probably somewhere in the vicinity of 150 to 200 UK pounds might be involved.

Secondly, you need to ensure that whoever does the work is something of a guru. I know that UK is well served by a number of such people, I am unsure of the situation "across the pond."

Once sorted though, a good maggie is a delight to use and has a number of advantages over coil ignition in a car which is not driven constantly.

regards

BLR

Yet again this demonstrates what a great forum this is when a quest for advice brings forth a seemlingly endless supply of knowledge and experience. There can be few other sources that can match this for us Seven enthusiasts. Thank you to all the experts.

Happy New Year to all!

Many thanks to Mac and Barry for their valuabe information. In the meantime I have also found there is a wealth of information on Magnetos on the Internet,and my conclusion is that there is no satisfactory way to test the coil. The best idea is to try a good one in its place. So today I went to my local outboard motor repair shop, and they let me look through their old stock. I found one that looked similar which they only wanted $5 for ( 3 Pounds ) Once home I cut up a electric moter for the core plates, and within 3 hours I had it working perfectly. So now its back to rebuilding the engine, once the parts ordered arrive from England. The next thing I am looking for is the end cap for the Dynamo which covers the brushes, anybody have one laying around they might be using for an ashtray ???
Once again thanks to everybody for there help and this forum for being here. Brian.

Dynamo end covers are available New and used. Try Sevenworkshop sales@sevenworkshop.com as a start.