Miller Waratah headlamp bulbs ?

[R]

My little Waratah (Excelsior) postwar 125cc needs some headlamp bulbs in its Miller headlamp.
Which looks to be 5" or maybe a bit bigger.
It merely has a switch in the top of it

What voltage are these bulbs ?
I wish to use it with a 6v battery.
(and did I read that the originals powered from the flywheel were 4v ??)
There is nothing marked on the existing bulbs.



Quite a big seeming bulb - with dual filaments
And an itty bitty little screw-in pilot lamp (battery 4.5v dry cell powered.)
What should I be looking for ?



And, the little bolt securing the rim at the bottom has nothing to screw into.
Was there some sort of little bracket through the slot in the headlamp bucket ?
Despite appearances, that is 1/4" cycle thread.
So, what am I looking for ?



Hope someone knows these things ....
Thanks in advance

[R]

Hmmm, a bit of scouting around reveals that the parking bulb is a screw in E10 sized torch bulb.
And 3v

https://i.ebayimg.com/images/g/MukAAeSw171p8K~t/s-l960.webp

However, there are LED versions of these, and some are rated to 24v
And some rated for AC use

Now for the main bulb

[R]

Only $30 for a bulb, and $15 postage
Blimey  !!

https://i.ebayimg.com/images/g/R-AAAOSwX-Bf7ebG/s-l1600.jpg

Wattage might be too high.
Not sure that the 2 little pins are in the right spot either .....

[33d6]

That immediate postwar period your Waratah/Excelsior hails from can be maddening. As Carden rightly points out it was a time of shortages and confusion so what was fitted was what was available, not necessarily what the factory said should be there. On top of that Villiers made a variety of lighting systems for the 9D so you have both the desperate times variations plus the factory standard variations and on top of both these is the regular dry battery parking light arrangement that accounts for your odd little Edison screw in bulb.
We'll deal first with your parking light bulb. The Edison screw thing. This is just an ordinary torch bulb of the time meant to run off two 'D' size batteries. Same as found in any hand torch of the day. If you remember in your childhood, shops sold these funny flat pack batteries with two 'D' cells side-by-side for bicycle use rather than the separate two in line as normally found in hand torches. One of those flat pack batteries clipped in behind the reflector inside the headlamp and powered your wee little edison screw bulb. A horrible set up but met English law of the time. You seem to have that one sorted anyway.
Now for your headlight. You need to ascertain what you have. All are 6 volt pf course. Firstly you have to check whether you have an 18 watt or 24 watt system. The armature assemblies of both are identical. The difference lies in the width of the flywheel magnets, 1&1/8" for the 18 watt version, 1&7/16" for the 24 watt job. What are yours?
Secondly we come to how the lighting coils are actually wired up. Commonly separate coils are used for the head and tail lamps so two separate circuits. Usually obvious as there are two leads coming out from the back plate. Red lead being the head lamp and the black the tail lamp. But Villiers also made some systems with a head lamp lead only so only having one lead out.
Finally Villiers also warn of poor earth connections. The earth lead of the tail coil is soldered to the side of the coil cheek and the earth lead for the headlamp coils is clamped between the coil cheeks and the armature back plate. Both are noted for causing mystery troubles.  Dim lights and mystery black outs.
That's enough to keep you occupied for a day or two, I'll be interested in your findings.
One last thing, What is the engine number? I'm sure I've mentioned this before but the initial batch of postwar Excelsior coming to Oz were fitted with ex-WD engines. Easily identified as the engine number ran vertically down the rear of the gearbox in the last of the AAA series, AAA****A whereas they then moved to the postwar engine numbering system found on a raised boss on the right hand side gearbox end plate. What is yours? Cheers,

     

[R]

Thanks.

Ah, so the headlamp bulb is 6v.
With no markings on it, is there some designation to obtain a new one  ?

AI suggests this could be 15/15W  (if you trust AI)
This LED one does look to have the correct base fitting.
https://www.oro2u.com/media/catalog/product/cache/fcb5851806c6fc4802571d138709ed85/4/4/44-295-led.jpg

I doubt this will ever do much night time running, so just switching on from a 6v battery will suffice to start with.
Constant loss, as it were. Battery charging, I'll work on it ...

[cardan]

Easily identified as the engine number ran vertically down the rear of the gearbox in the last of the AAA series, AAA****A whereas they then moved to the postwar engine numbering system found on a raised boss on the right hand side gearbox end plate...   

There must be a bit of overlap: here's a "postwar" number running vertically down the back of the gearbox, on a very original postwar Acme, maybe 1947-ish. 351/1287 is a pretty low postwar number, so I assume they were on the back for a while before moving to the end plate of the gb?

Leon