1929 Lucas Magdyno MDB Instruction Manual

With things being smaller on a motorcycle and space verses design sometimes provided difficulties on where to place things, so the combining of the magneto and generator into one unit was definitely a good idea. By 1929 generators were becoming a little more popular with the motorcycling British though for some there was still resistance to such modern electrikery with a preference for the old acetylene gas lighting. However the end was in sight for the primitive glow. This was due to the change in laws that meant that machines introduced from 1930 had to be fitted with electric lighting by the manufacturer. Joseph Lucas was already providing both gas and electric lighting units (we have listed a Lucas manual for 1919 equipment here) and although many people scoff at the Prince of Darkness’ efforts he did manage to survive for another 70 years.

Lucas’ E3 generator goes back to the late 1910s and was probably criticised by those who didn’t understand charging systems and by those who ignored the basic maintenance requirements, namely the battery (or to some the accumulator). But by 1929 things were changing and some riders were becoming more trusting of Mr Lucas’ efforts. The all common E3 charging unit could and would provide dutiful service, and lets face it acetylene lighting also had its issues (acetylene generators failing, rubber tubing to transport the gas to the headlight and tail light perishing and failing causing unnecessary fires, headlights being extinguished by winds, sometimes even just trying to light the headlight gas jet could be challenging).

So moving on to the 1929 MDB magdyno what was on offer for the modern rider? Well the generator was a 3 brush unit with a regulated output of 4-5 amps (higher current outputs could be achieved by adjusting the 3rd brush however all this would do would be to overheat the armature and cause premature failure). Regulation was controlled through the light switch with the following charging positions –

Off” – All lamps off and dynamo not charging,
C” – Lamps off and dynamo half charging,
L” – All pilot lights on (but not the headlight) dynamo giving full output,
H” – Headlight on, dynamo giving full charge output.

Magneto maintenance is very basic and covers the adjustment of the points and cleaning of the HT pickups and slip ring.
The manual also has some basic fault finding techniques for both the magneto and generator, which are still applicable today, and a brief instruction for timing the ignition for single, 2 cylinder and V twin engines.

Click on the front cover below to see the complete 31 page manual.
It is a 4.6M PDF.


1929 Advertisement for Lucas Magdyno and Lighting Equipment.

Need to know what wire goes where, then this may help.

We have also listed a copy for the 1930 Lucas Dynamo Lighting Set Running Instructions for the E3 and E25 here.