Hi Steve. Back in those days I'm not aware that rubber was ever used for petrol cap seals, I've had many bikes up from pre-war to the seventies and all had cork. Plus of course wartime shortages would've meant rubber was in short supply anyway.

Vincent.vanGinneke wrote: ↑Fri Oct 14, 2022 7:41 pm A 'upright' picture that is to big (over 1 Mb or so) it happens that they get sideways.
solution would be to make them smaller first in 'Paint' (well, thats how I do it)
But with a upsidedown picture.....

I will try experimenting more in future before I post

Help moderator, can you reverse that please? A trial.... Downloaded, rotated 180 in viewer and re-saved. I'll see if I can actually replace the pic in the original post when I've got more time - it involves some careful digging around under the bonnet. Edit - replaced the upside-down pic in landsca...

Help moderator, can you reverse that please?

Sorry these pictures are not particularly artistic, or even interesting, it's the best I can do. In May I attended the Vintage Revival at Montlhery in France, an excellent event that is held every two years. Montlhery, as I'm sure most of you know was the French equivalent of Brooklands, but is stil...

Tony I've been taught that the way to do these is to finish with coarse paste on the outer face and fine on the top of the spigot, so that when the head is seated there's a few thou gap on the outer face. Then when the head is tightened down seal is essentially on the very outer edge of the spigot,...

Either the liner was not fitted correctly in the first place or it has moved. It is usually held in place by an interference fit but if it is not tight enough it could drop down, however it looks like your cylinder has seen some use so if there was to be a problem it is likely to have happened by n...

If it's not touching on the outer area just get a good surface on the inner one. IF you're after the best get both surfaces involved but lap the outer a bit longer with oil only on the inner so the inner gets more pressure on it's surface.This arrangement is very satisfactory and needs no gasket. o...

Evening all. I have been lapping in my 350 iron head to barrel joint. I was quite happy with the result, but then taking a second look, realised that the liner is a thou or two lower than the actual barrel spigot. The spigot has an even look with the head face, but I'm wondering if the liner should ...

Are they the rollers from the centre of the chainwheel?