classic motorcycle forum

These bikes were sold as cheapest-of-the-cheap commuter bikes, and if the battery went flat occasionally then just charge it up.
No-one expected anything else before the Honda C50 came along.

In the late 40s early 1950s, you could buy a basic little Villiers powered bike with direct AC lighting only.
Or, the upmarket version with 6v battery and charging system.
And the direct AC lighting was still available, selectable on the (special) Miller 4 pole headlamp switch.

I was somewhat bemused to see the battery charging system seemingly has no voltage control (?)
Or have I missed something ?   How did they get away with this ?
Does the half-wave rectified 6v output only constitute a trickle charge to the battery maybe  ?

Does the base model Villiers have the same number of lighting coils for the flywheel as the battery model ?

Jist curious, at this stage ...

Could the tanks for 1947 C10 and A7 be common  ?
Might need parts books to say for sure.

Perhaps a PO was going for that retro look......

Take a photo / measure the combustion chamber while you are at it. ?

That does look like a copy casting, its not clean enough to be a Villiers product. ?
Your combustion chamber possibly hasn't had the final machining to give the correct dimensions ?

The advent of ashless oils was a huge leap forward in oil technology, especially for 2 strokes.
I'm likewise unaware of these 'inertia rings', and thought I'd kept up with most such developments ...

Hi Keith,

No I don't think the "inertia ring" (see collected guff below) has anything to do with it. Sounds like the compression is unnecessarily high? Maybe the head has been shaved, or if it's new perhaps it has a smaller combustion chamber than the original. I bet it would run better and last longer with lower compression... try a thick copper head gasket?

Fitting a decompressor would work too, but I suspect the compression needs to come down a bit too. The Brooklands Villiers in the photo higher up had pretty high compression, but was not hard to kick over. Ditto various Bultacos in my younger days.

Cheers

Leon

"We may mention the provision of a single thin ring, called the inertia ring, above the top of the first pressure ring on the piston. This ring is free to rotate and to move up and down slightly, and it has been found to be very effective in keeping the rings free from gumming deposits."

"The Villiers 346cc long-stroke engine was fitted with a patented inertia ring, which was one of the most important improvements made in two-stroke engine design for many years. The object of the inertia ring was to prevent the gumming up of the ordinary piston rings, and it achieved this object in a very simple manner. In practice, it was found that a film of oil formed above the piston rings gradually became burnt and carboned, eventually fixing the rings solid in their grooves. The inertia ring, which was fitted above the top piston ring, was designed so that it could not touch the cylinder walls. It was permitted to have a slight up and down movement and to rotate freely. This movement prevented any film of oil forming above the piston ring and so kept the rings quite free."

"It is interesting to note that the latest 148 cc. Villiers engine has an inertia ring in the same groove as the upper piston ring. Because of its “floating” the inertia ring scours the top ring and groove and prevents it sticking up for long periods."

"The piston is of cast iron and carries two compression rings; in the upper groove is a special device patented by the makers of this engine, known as an inertia ring. The object of this ring is to prevent the piston rings from sticking in their grooves. This inertia ring is clear of both cylinder and piston walls, and is free to move within its own clearance limits, thus tending to keep the ring and groove clar of carbon deposit."