SD Fuel Cap

[Collector Inspector]

I made the mistake of reading the SD topic that has recently refreshed itself.................I am now going at one of mine (assembly of pre-prepared bits) and need a cap.

Anything considered, just has to stop fuel escaping basically.

Bayonet fitting thingy. Steel tank type.

Regards

B

[Keith.P]

Is not the cap on the old 40's Anzani ss the same?
You must have some of them about.

[Collector Inspector]

Sadly I do not, only Anzani threaded

B

[Keith.P]

Sadly I do not, only Anzani threaded

B

Is it.
My ones not, its a bayonet

[Collector Inspector]

Did a hunt around and found one that fits! I think it came with a brass tank on either a TD or TC?



Now to clean this tank up..................Happy!



Problem solved.

B

[Collector Inspector]

AHA!

More digging around and something more like it!



B

[Oyster 49]

B, those caps are available to buy new, but without the air vent bit. They are made by a firm in Wolverhampton, and are often on ebay. When I get around to it I'm going to get a couple of vents screw assys made.

[Collector Inspector]

Well Well Well (three Holes In The Ground), you are spot on with that...............they have been around for 70 years.

Did a Google on em. Details are under the cap

http://www.wmccm.co.uk/WMCCM/WMCCM/Comp ... temid=1396

COOL!

B

[Oyster 49]

Yes, Ceandess ltd. They even make the neck assys that braze into the tank for these bayonet tanks. Good demand from classic bike restorers I think.

[woodbutchergraham]

Could some one do a drawing of the parts of this venting sytem even a photo of the cap stripped. Im sure im missing somthing (we all know that i am) but off my tank cap !

[Hugz]

I think mine is reasonably original apart from the central spindle being replaced with a stud with a butterfly nut (probably more practical).

The cap assembly comes as fives pieces (six including chain to tank)

The components in sequence:

1. The Cap
2. Spring under Cap.
3. Internal larger copper dome
4. Outer smaller copper dome (that sits on base on the neck assembly)
5. Threaded spindle

Not sure if there was an original cork gasket. Will be interesting to see what others have. The tighter the spindle is screwed, the loser the fit. It is all a bit bizarre to me. More pics please of the original spindle.

[Charles uk]

There are 5 components comprising the air bleed nipple.

Working down in order
Nurled threaded 1/2" bit you twist to undo
Air release needle, then a thread for the undo bit, parallel section with a larger shoulder then a thread with a point on the end
Cromed domed threaded inside, cap
main air bleed bit comprising a boss with a shoulder boss threaded inside & out with a fine hole through the center down to a cross drilling in the middle of the prallel section, then a parallel section with thread on end for the
cap with a cross drilling for the ring that the chain fixes to.

The register had 10 made the year before last & I can't find the drawing we had drawn then, but they were so bloody expensive that only 3 registry members would pay for them.

[Hugz]

Any left over? The original didn't have a spring?

[woodbutchergraham]

Thanks chaps, I’ve been playing around trying to get something like the original one. I have cobbled something together to get me out on the water but once the workshops finished should be spending more time out there.