I THINK that the M2 was a magneto made (originally), without provision for advance-and-retard mechanism, and usually employed on flat-twin stationary/portable engines such as those made by Douglas and Norman, driving things like water pumps and generators. A lot of these appeared, (unused), in ex-War Department Sales up to about 25 years ago, and they had been intended for use on portable aircraft-starting auxiliary engines. They had aircraft-type shielded pick-up holders, and can be converted for bike use by adding the advance-and-retard bits, and by changing the pick-up holders. Barry Bassett did one for me years ago. I also THINK that MC2 was the proper motorcycle version, with the A&R mechanism fitted. I don’t know what the MD2 mags were intended for. It should be noted that these different versions, whilst of similar appearance, had different numbers of turns in the windings, and for instance the aircraft-starting mags were intended to give a big fat spark at low revs, and they do not take very kindly to sustained high revs. Do not forget that a two-stroke mag has to run at engine speed, while a four-stroke mag runs at half engine speed, and thus has a MUCH easier life. Talk to an expert for confirmation of all this !
Brian
