EW Carburettor

[Red]

I am trying to sort out the carb on my 1926 EW 350. Attached is a photo of the carb I have which I assume is an AMAC. There are no markings on the carb body and rather than having a clip fitting to the inlet manifold there is a screwed connection.
The jet holder on the left-hand side is the one currently fitted (I have not yet had the bike running) and clearly this has been modified with an adaptor to take an Amal main jet – size 80. On the right-hand side is what I think is a standard jet holder and this is fitted with a 29 jet.
Question 1 – the modified jet holder has raised the main jet by approx. 13mm. Surely this can’t be right? Should a do away with the adaptor
Question 2 – is this carb ok for the EW 350 – bore size looks to be 11/16 inch. Also are Amal and AMAC jet sizes the same.
Any help would be appreciated. Many thanks.
Roy


Image converted to linked file to correct distorted display. Please see Taking photos with mobile/cell phone - Dave, 07May2023

[cycarmark]

According to Radco, the AMAL 80 and the AMAC 29 are equivalents.  Whether they are correct for your bike is another matter.

Hope this helps.

[cardan]

Hi Roy,

Your carb is probably the original for your EW: AMAC made a carburettor especially for the EW - see attached.

Through the early 1920s AMAC used a submerged main jet with a row of "sprayer nozzles" along a ridge under the slide. The EW AMAC is a variant, also with a submerged jet but with a mesh under the slide instead of the row of sprayers. Not sure how well it worked. The EW is more often seen fitted with a B&B, but I'm not sure if this is because the b&B is "better" than the AMAC.

Anyway, because the main jet is submerged its length is unimportant because it lives in a lake of petrol. The jet just meters the petrol, rather than spray it as occurs in later carbs like the AMAL. Unlike later carbs, the fuel level as set by the float is higher than the top of the jet.

Cheers

Leon

[Red]

Thanks to you both for the information. I will fit the standard jet holder initially and see how I get on.

All the best

Roy