Author Topic: Brown & Barlow carburettor 123-5 for EW 350  (Read 5057 times)

0 Members and 1 Guest are viewing this topic.

Offline Edin

  • Full Member
  • **
  • Join Date: Oct 2006
  • Posts: 90
  • Location: Denmark
Brown & Barlow carburettor 123-5 for EW 350
« on: 24 Mar 2013 at 18:02 »
Hej all.
Can someone please help and inform me about correct hole diameter in the main jet on  B&B 123-5 carburettor,- fitted to an EW 350.  I think the main jet on my 1926 EW 350 ccm Sport,- is much to big.
I would be gratefull for information about this measures.
Regards Edin DK

Offline Alan

  • Senior Member
  • ***
  • Join Date: Apr 2004
  • Posts: 166
  • Location: Australia
Re: Brown & Barlow carburettor 123-5 for EW 350
« Reply #1 on: 25 Mar 2013 at 03:06 »
To quote directly from the "Running Instructions for EW Model": Douglas Motor Cycles.....The carburettor ( B&B) is fitted with two jets- a pilot and a main, the size of main jet may vary slightly with different engines and varying conditions, but generally speaking a 75 Jet should be found correct.

Offline cardan

  • Master Member
  • ****
  • Join Date: Jul 2007
  • Posts: 1529
  • Location: Adelaide, South Australia
    • Leon's Vintage Motorcycle Page
Re: Brown & Barlow carburettor 123-5 for EW 350
« Reply #2 on: 25 Mar 2013 at 03:49 »

(My little book says that a B&B 75 jet is about 0.029" diameter.)

Leon

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4641
  • Location: Glen Mills, PA, USA
Re: Brown & Barlow carburettor 123-5 for EW 350
« Reply #3 on: 26 Mar 2013 at 03:42 »
Edin,

There were two possible  types of 123-5 B&B carbies being fitted to 350EWs at this time. One was the gauze type and the other had a taper needle. A different style main jet was fitted to each, and the default jet size may have differed depending on type. As Leon mentioned, the EW handbook states a #75 main jet. Since the latest handbook I have dates for the 1926 models, I am pretty sure this is for the gauze or needle-less carb.

The needle jet carb seems to have become standard fitting on the 1929 600EW models, but I am not sure if that was the case, or when, or if ever, the 350EW got the same. Also a Sports EW may have had the needle jet carb while the standard 350EW did not. in any event, I have not seen any clear information what the default main jet size would be for a 350EW fitted with the taper needle main jet.

Doug


[Change "1928" to "1929". 26Mar13 -Doug]
« Last Edit: 26 Mar 2013 at 21:45 by Doug »

Offline Edin

  • Full Member
  • **
  • Join Date: Oct 2006
  • Posts: 90
  • Location: Denmark
Re: Brown & Barlow carburettor 123-5 for EW 350
« Reply #4 on: 26 Mar 2013 at 07:28 »
Thanks to - Alan - Leon and Doug for reply and help ,- it is just what I needed.
Regards Edin DK