classic motorcycle forum

I’ve hunted out the magnet details for you R. Magnets on the 18 watt job are 1&1/8”wide and the 24watt magnets are 1&7/16”. The difference is in their width.
One has to be careful with Villiers magnetoes. There can be subtle differences that are never mentioned anywhere. For example the overall flywheel width of the near identical post war 10D and 6E engines are different, the 10D is 1&7/8” and the 6E 2&1/16”. I’ve never bothered to measure the actual magnets. This is never mentioned anywhere in any Villiers manual I’ve seen. I suspect it never occurred to Villiers that it would ever become relevant.

For various reasons I haven't been looking here much lately so have come in at the end of the above chatter. I gather from what has been said on previous occasions that you are writing about your 9D powered Waratah/Excelsior R. If so you don't seem to have a relevant Villiers manual which does make it a little tricky. I'll start with the first question and try to work through them all.
Of course there's no voltage control. Can you think of any British bike of the time that DID have voltage control on an AC system? I think Triumph were more or less the first major factory to fit alternators. They had the same lack of voltage control and those following weren't much better. I remember much unhappiness about batteries boiling dry and other woes in the early years of it all and a distinct lack of enthusiasm about the infamous multi-terminal Lucas combined ignition and lighting switch. What was it? the PS or PSR8? It's no consolation but Villiers were no more and no less ghastly than much more expensive machinery. Let's face it post-war British motorcycle electrics were never world leaders.
Essentially the factories fitted only the one size 6Volt battery, I don't think they had much option. I think it was the only one available and it seems as it acted as some sort of electrical buffer in these systems. They all seemed to revert to the old three brush dynamo idea of a daylight charging rate and a night time head lights on charging rate which never worked particularly well. I'm no electrician, maybe there was some sort of secret to it.
Next, there were two lighting systems used on the 9D. From memory, 18 watt or 24 watt systems. The lower wattage having both fewer coils and smaller magnets. You appear to have the lower wattage cheaper system fitted. Perhaps this was one of the ways the factory differentiated between an Excelsior or a Waratah. I don't know. Whatever, they are both standard Villiers systems of their day but you have to work to the limitations of each.
As for light switches Villiers supplied a relevant light switch for whatever lighting system you used, rectified lighting with a battery or directly off the lighting coils. The four position switch was late on the scene, well after your wee bike. Before Villiers provided this switch to change between steady battery lighting for town use and 'direct' lighting for country running the knowing rider wired in an extra dip switch and used that to flick between the two systems. Eventually it dawned on Villiers that they could add the dip- switch trick to their standard switch and sell it as a standard function but as your bike predates this you could use the extra dip switch concept as being absolutely correct for the time. Just remember that LED's probably wouldn't like the change to direct lighting too much. They're rather keen on a steady current without erratic swings. It's an arrangement for old fashioned bulbs only.
Finally I'm in complete agreement with the idea of a brake/stop light on any bike. I have absolutely no faith in any following traffic.
Anything else I need to cover?   

I understand your lack of concern over lighting. Who does expect to go riding one of these beastliest at night anyway BUT, (there’s always a but) you do occasionally get caught out. Country town rides and rallies have caught me out a few times, somehow you end up at a local riders home or a different pub and bingo, it’s got dark quicker than you expected. I also like to have a brake/stop light fitted. I have little faith in the road users    following behind. Many only react to brake lights and never think beyond them.
You can fit a battery powered total loss system but then you’re always faffing around charging up batteries. Fit a basic direct lighting set up and you always have no hassle lighting but the brake light set up is iffy. There’s never an easy and simple 100% satisfactory solution is there.

I smiled at the 4.5v battery chatter. They can be sheer frustration. I don’t know exactly when they went off the market and I have mucked around making them up from two ‘D’ cells but eventually I got fed up and stopped bothering. I don’t know how many hours light they originally gave but wangling a replacement in and out of that headlight clip every month or so would drive me nuts.

This is just to say I'm finding it near impossible to get on to this site. I thought it was my old computer which was having various painful bothers but I now have a new computer and if anything things are worse. I've had a real dance around to get on and much emphasis from my new electronic friend about the lack of security involved in getting on.
Does anyone know if Nigel is still supporting it? From the lack of traffic I don't think so.

As for your Villiers switch R I think expecting anything straightforward from any bike produced in the 1945-46 immediate post war period is being very hopeful. As far as I can make out bikes were built up with whatever material manufacturers could get their hands on. The Vic State engine number records show the early post war Excelsior all to be fitted with ex-WD engines. The post war engine numbers start several months later, presumably from a later shipment of bikes. What type of engine number is on your Waratah. Ex-WD AAA****A vertically on the back of the gearbox or post war style on the R/H side gearbox cover? And yes, Villiers seemed to have close links with Miller as they did with Albion but I don't know how formal these were. I've never managed to pin these associations down. Villiers, Miller and Albion have never been treated kindly by the British motorcycle fan base. They seem to find it hard to get beyond the Boring Big Three. C'est la vie.

As you know, your AJS is essentially a re-badged Matchless. By far the best owners workshop guide for you is the “MotorCycling” Maintenance Series covering Matchless 350 & 500 cc Heavyweight Singles 1939-1955.
Republished by Bruce Main-Smith Ltd in 1976 and as they say “intended for Matchless but good for AJS too.”

It contains every bit of technical information you’ll ever want to know plus all the technical differences from year to year and lots of clear illustrations. You’ll love it.

A4 landscape size, published by Bruce Main-Smith Ltd and edited by Reg Hide. Get a copy.

The Mk II designation on the underside of the float bowl refers to general improvements across the whole Villiers carburettor range. It serves no other purpose and has no role in identifying any individual part or individual carburettor. Ignore it.

Your 1 1/8" carburettor is a Villiers MW (Medium Weight). It is intended for use with a Villiers lever throttle NOT a later self closing twistgrip throttle.

The Mk XIIC was fitted with the MW (Medium Weight) carburettor as standard. It was set up with a number 2 jet (the centrepiece) and a number 4 taper needle. Both the jet (centrepiece) and taper needle are stamped with the relevant numbers. Be aware it is very easy for the MW needle and centrepiece to be confused with the similar but shorter parts used in the Villiers LW (Light Weight) carburettor. It is easy to confuse the two.

If all parts are in good condition with the float level set to Villiers specifications the carburettor will work exactly as the maker intended without any further adjustment. Please note there is often a difference between what the maker intended and what a current owner thinks it should do. 

Yes we do. We went down that rabbit hole exhaustively some time back. You’ll have todo a little exploration of earlier posts.