These are generally referred to as "Edgar Westbury 80 watts". Edgar Westbury, working under contract for Stuart Turner, designed these neat little 80 watt 12 volt units in the early years of the Second World War for battery charging in the armed forces. They were soon in production by Douglas Motors, Enfields, Stuart Turners and EEC - probably Electrical Equipment Co, though some believe it to be Economic Electric Co. They were ground breaking units at the time as it was rare indeed to set out to design a small capacity (15cc) high revving (3,500 RPM) four stroke, side valve, all aluminium engine in an age of heavy, slow revving motors. They gave very little trouble in their day and were especially valued for ease of starting and spikeless power output. The latter is due in no small part to the inclusion of a separate ignition generator unconnected with the main alternator.
There are still a few about that have seen virtually no use at all. I've got such a beast, complete with it's canvas cover. The badge on the crankcase that says "ECC 1945" (Enfleld Cycle Company) is still in its yellowing varnish over brass. When I tried to get it running after purchase, it had a depressing lack of ignition electrickery. It is very nicely made and the tiny plug hides inside a fully shielded lead that runs in armour plated magnificence back to the black plastic ignition generator cover. It is a pretty major excavation to get at the points as the carrying frame, the carb, the heat shields and the plug lead all needing to be removed before it is possible to take off the generator cover. After that, it is plain sailing. The points are opened by a rising pin a'la Briggs & Stratton and very often the pin is seized or stiff & might need cleaning. The points are often clagged with storage oil though, but that soon gives way when faced off with 600 grit W&D paper and a blob of spit!
Personally, after so long without running, I like to drip a bit of petrol onto the air filter element to give the direct lift carb a head start - frequently, this is all it takes to make it splutter and run. Without a battery attached, the generator puts out 38 volts. Connecting it to a 12 volt battery induces the nominal voltage to rise from 14 to 17 volts, the revs drop perceptibly and it runs more steadily.
They don't much care for running much below their design speed - probably the direct lift carb can't maintain a decent flow rate at lower revs & it just dies away in sad fashion. I find mine hard to start from hot, probably evaporation in the lift pipe.
As to lead or not to lead, I'd really not worry about it, it isn't as though you are going to run it all day or even every day. If still nervous, add a dash of two stroke oil which will act as UCL too - but not so much as to make it smoke or you'll weaken the mixture.
Regards,
Kim Siddorn