Author Topic: 1927 EW350 carb saga  (Read 5049 times)

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Offline Douglas52

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1927 EW350 carb saga
« on: 02 Oct 2008 at 10:25 »
Well the bike is going great, but the carburetion is shocking. It wont take full throttle but runs surprisingly hard.
I pulled the (Amac?) carb to bits and found a strand of fuse wire had been inserted through a huge main jet drilling. Never come across that way of leaning out the mixture before, but its no doubt an old trick, and helps explain the evolution of the needle jet. Amid the spares that came with the bike I found a carb body identical to the one fitted - see photo. Could someone confirm that it is actually an Amac, and not something else with an Amac float chamber on it. It still has a vaporiser but th air slide has been removed.
If anyone has any information on carbs like the one in my photo I would appreciate some help. Float level and jet sizes would be of help.
Also especially with regard to the air slide - I assume these are just a brass cylinder with cable connection which fits in the throttle slide. I want to make one of these and hook it up  in an effort to help with carburetion setup, so any dimensions, photos, operating advice etc would be appreciated. I'm hoping a working air slide will help me sort out the jetting and air leakage.

If things dont work out I'll take Alans advice and fit an Amal 274 so if anyone has one keeping the garage door open I'd be pleased to hear from them. I intend looking for an Amal as plan B anyway. The bike came with reasonable stash of spares, so we might be able to do a part exchange.

I'm still a bit in the dark concerning engine lube rates. Saw somewhere about six drops per minute, and thats what I've been aiming for. However I expect seizure anxiety is resulting in a rate more like a pint a minute. The manual says one manual pump stroke should last about 7 miles, but the pump on my bike is a bit leaky. One of the comments I found on the site was to adjust lube flow to give a slight exhaust haze. Ive been aiming for this and backing off when things get a bit smoky.

My bike came with an original manual: "Care and maintenance of the 350cc E.W. Douglas". Its a bit dogeared and yellowed, but if anyone would like a copy, I could scan it . Shouldnt think there would be any copyright issues after 80 or so years.



« Last Edit: 03 Oct 2008 at 20:38 by Dave »

Offline Doug

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Re: 1927 EW350 carb saga
« Reply #1 on: 03 Oct 2008 at 00:33 »

There looks to be a "30 H Y" stamped at the base of your carb, as well as a part number. T.30HY is a proper nomenclature for a 1923-27 AMAC. I have not seen one with the 'ledge' where the auxiliary air ports at the base of the jet block are.

Typically a EW would be fitted with a 123 Brown & Barlow.  (123-5 cast on the mixing body). But in an 1926-27 AMAC catalog photocopy I see a special AMAC "T. 30 W." made specifically for the EW, and it could be considered an alternate item fitted by the factory. This shows a castelated gland nut like what you have and in general agrees with the carb you have shown, being a sprayer type (no needle.) It has the lumps and bumps in right right places, but no 'ledge'. I can not tell if it is drilled at the base like yours. The catalog says the mixing chamber part number is 3479 (that does not look like your number), and the float chamber part number (shared across models) is 2033. It shared other common parts with the T.30HY.