BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Keithy on 16 Feb, 2019, 09:46

Title: C15 petrol tap
Post by: Keithy on 16 Feb, 2019, 09:46
Hi, I've recently moved, and was in the process of painting my tank. In all the upheaval, the fuel tap has got lost.
Can anybody tell me the size of the thread in the tank please.
It's a 1959 C15
Thanks
Title: Re: C15 petrol tap
Post by: rimmer on 17 Feb, 2019, 10:50
Hi, the thread in the fuel tank is 3/8 BSP/Gas
Threads are measured using the bore of the pipe so 1/4" BSP relates to 1/4" bore pipe and so on therefore the thread, because it is on the outside diameter of the pipe and allowing for the wall thickness, is bigger than you might expect...!!
If a replacement tap has a 1/4 thread you can get a 3/8 to 1/4 reducer.
kev
Title: Re: C15 petrol tap
Post by: Keithy on 17 Feb, 2019, 11:14
Thanks for that, I'll start looking for a tap now
Title: Re: C15 petrol tap
Post by: MICKREEVES on 18 Feb, 2019, 15:53
I bought one which came with an adapter, so will fit either 2/4 or 3/8 threads
Mick
Title: Re: C15 petrol tap
Post by: BeenyBoy on 19 Feb, 2019, 10:05
Just make sure its ethanol proof...I've just discovered the sealing washers on my new replacement tap have disappeared....
Title: Re: C15 petrol tap
Post by: ANDY HIGHAM on 19 Feb, 2019, 14:39
What the hell were they made from?

Common rubbers used for seals and O rings
EPDM,  Ethanol excellent, Petrol unsuitable
Viton, Ethanol moderately suitable, petrol excellent
Nitrile, Ethanol excellent, petrol excellent

From this I would deduce your seals are EPDM rubber and the petrol has knackered them, not the ethanol
Title: Re: C15 petrol tap
Post by: SUPERGRUMPS on 19 Feb, 2019, 16:37
Just obtained a tap from Andy davenport (Vincent Parts) for £14.00 inc P&P. Replaced mine as I wanted one with a reserve facility.
Title: Re: C15 petrol tap
Post by: BeenyBoy on 20 Feb, 2019, 09:53
apparently the washers are ethanol resistant- prolonged exposure- leaving petrol in the tank for a month or so can causes them to degrade. I've replace with PTFE washers which are apparently more stable...we'll see
Title: Re: C15 petrol tap
Post by: berniej on 20 Feb, 2019, 14:21
Supergrumps - did you find a three position tap - on/off/res ? Looking for one myself but couldn't see one there....

Cheers,
Bernie
Title: Re: C15 petrol tap
Post by: SUPERGRUMPS on 20 Feb, 2019, 16:51
Hi Bernie, yes, its a push and pull for on and off and a separate lever for the reserve. If you look on ebay its under VINCENTPARTS. Only £14.00