Bayonet Fuel cap

[Adrian Dale]

Has any one got a BS bayonet cap hiding in their shed?? PM please

AJ

[headdownarseup]

I need one too...

I dont really want to put a motorcycle variant on the tank i'm doing at the moment. ( very early 102 AD)


jon

[jerseydave69]

I would like one too, if there is a cache of them sitting in someones shed ! Also a 102 copper fuel pipe please if anyone has a spare for sale .

Dave

[Keith.P]

Copper fuel lines can be made pretty easily, caps not so easy to find and I think most are hanging on to them if they have them, to be honest

[jerseydave69]

Do you know what size the fittings are for the copper coupling nuts ,for each end of the fuel line Keith ? They appear to be a different thread on each end ! ( Amal twin jet) ( Brass fuel tap)

Dave

[Horsley-Anarak]

I have an SD one

£6.00 plus postage.

H-A

[jerseydave69]

Great stuff Horsley, I will take it . I will P M you

Dave

[Oyster 49]

Thearts are available to make new fuel pipes identical to the originals. 1/4 copper pipe plus the end ferrules and nuts. Yes the threads are different at each end. Search previous posts, all the info is there...

[headdownarseup]

Speaking to Charles last night, it would seem that the bayonet fuel cap is becoming something of a rareity, especially when so many older generation seagulls were fitted with them. Marstons,SD'S, SDP's, early post war 102's (D,C,AD,AC,AHC)

I've been looking for quite some time now for a decent looking "replica" that will do the job.
The closest i can get is a motorcycle variant. The trouble is they dont have the proper breather nipple on the top. Priced at around £10 upwards.
All they have is a very small hole drilled in the top to allow for "breathing".
Close, but not close enough for my liking...

anyone got any thoughts?

jon

[jerseydave69]

What is the name/ description of the motorcycle variant Jon ? I'm trying to find a tank cap that will do the job...until ,if ever I get an original one !

Dave

[Adrian Dale]

I have one off a BSA bantam (I think) its in the UK so I cant get a it to check or photo. Any way they fit well but will leak out of the breather hole if the motor is laid own with a full tank. But until the original turns up they will do,

I have two bayonet caps but three engines that require them so its a matter of swapping around on the engine in use!

Still looking.......

AJ

[Adrian Dale]

I am thinking (dodgy) that with a motorcycle cap the basic bayonet and cover is identical so with a minimum of effort it should be possible to strip the cap then drill out the top to take a small valve. Just need to manufacture the little valve, which on a hobby lath shouldn't be too difficult.
Ill strip one of my originals down, (needs new joint any way) and see what I can come up with.

AJ

[jerseydave69]

Great stuff AJ I was looking online earlier today and found some English made new caps for old bikes etc. I just need to measure my tank in the morning to see what diameter the cap needs to be ! I'm thinking a 2" inch one ! I will also try and find a way of making a vent valve ,once I get hold of a cap ... First things first eh ,Ha ha !!

Dave

[Charles uk]

Why doesn't someone take the air bleed vent to bits & do a sketch of the components, If I remember right there are 5 of them, all threaded.

If someone's going to remanufacture an exact copy, the Marston register is going to need 11.

[Horsley-Anarak]

I am thinking (dodgy) that with a motorcycle cap the basic bayonet and cover is identical so with a minimum of effort it should be possible to strip the cap then drill out the top to take a small valve. Just need to manufacture the little valve, which on a hobby lath shouldn't be too difficult.
Ill strip one of my originals down, (needs new joint any way) and see what I can come up with.

AJ

should be quit easy, will look the part.

I would start with one of these unvented oil caps

http://www.thunderbirdspares.com/oil-ta ... -469-p.asp

H-A