1927/8/9 Brown and Barlow 123-5 Carb help

[Daren W Australia]

Hi,

 I'm working on my 27/8 600cc sv and 29 600cc sv Douglas, Brown and Barlow 123-5 carbs.

 I have one complete (1) in 2nd photo is this the correct lid ?

 one that needs choke slide, needle, float and lid (2)

 one that needs almost everything but the body and bowl (3).

 Is there a supplier of parts for these online or do you have these bits in your garage ?

 Thanks Daren

[cardan]

Hi Daren,

Very difficult to answer your questions, because the 123-5 doesn't appear in the usual B&B literature, which would have us believe that the 123 carburettor wasn't fitted with a pilot jet, and yet the 123-5 clearly is. Perhaps it was made specially for Douglas?

Also 1928-1929 crosses the boundary between the old firms (AMAC,B&B, Binks) and the new (AMAL). Technically a B&B wasn't available in 1929, yet I bet they were supplied. Were some sold with AMAL float bowl lids? I don't know, but yours it the early AMAL type. I'd guess they had B&B lids originally, even if supplied in 1929.

Parts? I've suggested asking seller b561 on ebay before: he makes lovely parts and reconditions carbs, though more AMAC than B&B. Here's an example: https://www.ebay.co.uk/itm/143927411703

Here are the relevant parts lists, even though the 123-5 is not mentioned specifically.

Cheers

Leon

[cardan]

Looking further, I see from B&B List 26 (maybe 1927) that the 123-3 had a pilot jet.

Are we sure that the 123-5 is big enough for a 600?

Leon

[Daren W Australia]

Hi Leon thanks have found him now will contact tonight

I have this printed www.barnstormers.co.nz/147/brown-barlow-carburettors-bb/

and this www.barnstormers.co.nz/barnstormers/wp-content/uploads/2009/10/Carburettors.pdf

found this www.vintage-motorcycle-spares.co.uk/brown-and-barlow-29-c.asp

would love to contact this guy www.flickr.com/photos/145850402@N06/25546706277/ but not sure how ?

Thanks Daren

[cardan]

Before you go too much further, I think you'd better double-check the size.

It seems the 123-5 is the smallest of this pattern of B&B - only 0.71" bore. This might be fine on an 350cc EW, but it's very small for a 600? Some sort of 121 might be better - perhaps the 0.78" bore model?

Leon