classic motorcycle forum

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 had a random thought about this engine. /I usually means 1927, but it can also mean 1947. Speedway engines aside, JAP didn't build many motorcycle engine post-WW2. I don't think it's really likely, but could this be a 1947 engine used in a European bike? All sorts of things were being exported from the UK after the war.

Leon

Hello
Many thanks for your response!
You are absolutely right- I am from Austria and I found this engine also here in Austria. As far as I know the 550cc engines where very popular in Germany and maybe also here in Austria. According to my research the "Y" on SV engines stands for the cheaper "Roadster" or "Standard" version. They has smaller valves and no rotary breather than the sporty SV K and U engines.
So far so good. But my problem is as mentioned before the fact, that normally the KY and LY engines has the sparkplug located directly on the intake valve cap, but my engine has a seperate hole for the sparkplug like the sporty K and U SV engines. But with the small valves and tiny cooling fins.
Very confusing....
Maybe it is really a industrial engine...
Thank you.
Regards
Ralf

Ditto.

Rob Saward has written a little booklet about dating JAP engines,
additional to all the pneumatic palava, as research into aussie built versions.
He'd be the chap to ask, although his health may not assist here.

Hi,
Has anyone every seen such a Roadster cylinder with seperate sparkplug hole like the SV sports engines K and U?
Furthermore this cylinder has very tiny but many cooling fins.
This cylinder was mounted on a 550cc Roadster engine from 1927 ( LY/I ). It has the original bore of 85,7mm and a stroke of 95mm, so it is a real 550 roadster barrel. But I haven't ever seen a roadster barrel with seperate sparkplug hole and such tiny fins.
In the pictures you can see this cylinder compared to a 500 roadster KY/W
Thanks
Regards
Ralf