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Some Ignition Hints & Tips

Philip Wintersgill

In the last issue of Buzzing, John Richardson asked about how to power an external coil from the magneto of his VAP4.  The best way of doing this is to use a second lighting coil in place of the original ignition coil, if one is available.  Another way around the problem is to remove all or part of the secondary winding of the original ignition coil, as it is usually the secondary winding that burns out.  Only the top layer of the secondary winding needs to be removed. The best way of doing this is to carefully slice through it with a Stanley knife, but you have to be very careful that you don't go too deep and damage the primary winding.  The coil can then be refitted to the back plate.  You then connect the wire to the points to the same terminal as the wire from the internal coil and condenser.  This wire can then be fed out to the outside of the magneto through the hole or grommet for the old HT lead.  This wire then connects to the external ignition coil.  The other terminal on the coil connects to a good clean earth point on the frame of the machine.  All connections should of course be soldered.

As to the types of coils to use, I usually use the Bosch coil, part No.0212940001.  This was used as standard on quite a few 1970s mopeds such as late Puch Maxis, NVT Easy Rider, Casal, etc, so it should be quite easy to get hold of.  I have also used a few other 6 volt moped coils, and have had no problems.  Please note if you use a coil with only one terminal, such as the one fitted to Mobylettes, it must be fitted to clean metal on the frame, as these coils earth through their fixing bolts.  The coil can than be mounted on the frame of the machine as close as possible to the engine to keep the wires short.  A mounting bracket will probably need to be made up.

Car condensers can be used on magnetos, but usually need to be mounted outside the magneto due to size.  The wire can sometimes go through the grommet that the lighting wire passes through.  If not, a small hole will need to be drilled in the back plate.  The condenser has to be mounted on clean metal so as to provide a good earth.  The condensers I have used include the Lucas type as fitted to Morris Minors, Minis, and a lot of other British cars.  I have also used the Ford type as used on a lot of Ford models, but I can't see why other types cannot be used.

I hope this information will help other NACC members.  I am currently running a Peugeot 102 moped with all the above modifications.  This bike is used every day, and always starts first time.

First published, October 2002

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