BSA 1960 Spitfire Scrambler Restoration.

[JulianS]

Converting to coil ignition means you need to find a suitable space to fit a dual coil and on/off switch and you become reliant on the charging system for your  spark. With Thorspark you retain the original magneto armature bearings and oil seal so they may need to be serviced as part of the conversion.

[Superarnie]

Thanks Julian, that's what ive learnt from researching it, but do you have a Thorspark system and if so are you able to comment on its reliability compared to say, retaining the old mag/points system? If you do have Thorspark, where did you install the coils?

[DAVE BRADY]

Hi,

A good mag. is hard to beat but the points and manual/auto advance retard is always going to be a weakness.  The auto units are never going to have much control over the advance and manual would be a constant fiddle to match the advance to the rpm.
Using electronic compensates for this with a built in advance curve giving the most retard for starting and on the simplest ones, a linear advance to maximum.  There is usually the need for a good battery as the advanced position is the default so a bit harder to start with a low battery.  A coil is also needed.
I fitted Boyer Mk3 to my wife's A10 many years ago and it made the bike a lot smoother and it pulled better through the rev range.  As a 'fit and forget' I did not have to do anything to the ignition timing.
The latest Boyer and the Pazon have a more retard making starting even easier and now do not need quite so much charge in the battery.

I suppose weighing up the cost of refurbishing a mag compared to the EI set up could be a decision maker along with how much is the bike going to be used?

Dave.

[DAVE BRADY]

Hi,

The EI on my wife's bike in a mag replacement housing supplied by Kirby Rowbottom.  I think that they do one that is basically  modified mag so an authentic look is preserved.  Boyer or Pazon should fit in these.

Dave.

[JulianS]

I dont have Thorspark.

My experience with electronic conversion was not good but probably not typical..

My swinging arm A10 (49 years of ownership and use) suffered a sudden magneto armature failure almost 5 years back, I could not get a quick rewind so considered an electronic conversion with the better weather coming.

I considered 3 options.

First the cheapest, Thorspark but rejected it because it retained the main mechanical parts of the magneto and I did not think it worth doing a part job.

Second the BTH self generating electronic mag. The most expensive one. I wish in hindsight I fitted had this.

I settled for the SRM mag kit which replaces the armature with a shaft and sealed bearing housing and Boyer Micropower setup. That did not work out very well. It was as if some spiteful gremlin had taken over the bike. It was hard to find a suitable location for the unusual shape of the Micropower dual coil and when I set it up it continually kicked back ( it was not the way I had set the timing) when I tried to kick started the bike. It did run but starting was not reliable and you needed to kick it over fast or it would advance and kick back. Tried 3 different Micropower control boxes over a number of months with same result. When changed to Boyer Mark 4 setup it started and ran very well.

It is hard to find a suitable mounting for the dual output coil (different to the Micropower item but same as Thorspark type) space is limited, some suggestions made vaguely suggest "under the tank" Boyer supply a mounting bracket/heat sink for this coil as an extra. Using the bracket I fitted the coil in the tool box and needed to extend the HT leads.

To be honest with the problems with the Micropower and drilling extra holes for mounting the coil and on/off switch I was quite disillusioned and did not quite trust it and missed the simplicity of a magneto. So gave up on it and refitted the magneto with a rewound armature (with thanks to Andrew at priory Magnetos). Not missed a beat since.

Photos show the coil mounting I used with the Mark 4 Boyer.

Photos show the coil mounted in my A10 tool box.

[Dean Southall]

You could consider a BTH electronic ignition. Self contained and needs no battery. I fitted one over 20 years ago to my Super Rocket. Performance and starting. tickover immediately improved. I have has to give it no attendtion at all since fitting it, indeed I forget its there!