Little brass tube in carb throat

[Lewes96]

Anyone know what the little brass tube slanting outwards in the bottom of the throat of the VHB carb? I have bought a new body and am fitting all the jets etc from the old one but finding this bit hard to remove. Just wondering how, and indeed what it is.
Cheers

[morini_tom]

Can you post a picture?

From your description it sounds like you’re taking about an extended atomiser, which is usually a 2 stroke carburettor thing…

[Lewes96]

See pic attached VHB25BS carb.

[morini_tom]

Oh yeah, that ones supposed to be there. I thought you meant pointing up protruding from where the atomiser meets the Venturi.

No idea how you’d get that out without damaging it. You’d have to check with fluid or air where the drilling goes but I suspect it feeds the idle/progression circuits.

If nobody here has experience of removing it, maybe eurocarb can advise? I’ve always found them to be very knowledgeable and helpful where dellortos are concerned

[mbmm350s]

It's called the air brake it can be removed but as it easy to clean on VHB(Z) carbs I have never needed to. It's purpose is to feed air into the atomizer if it is blocked the atomizer does not function correctly.
I don't think these are available as a spare part anymore.
Mark

[Lewes96]

Understood on the air feed to the atomiser. The existing body (being changed as the jet block split) has the pipe. The replacement has the passage but no tube (see pic). Just wondering if the lack of tube matters?

[3potjohn]

Look up those holes with a torch , I would think you should see there is a “ pinhole” narrow brass fitting in both orifices one for pilot and one for atomiser. It is possible to just see the needle passing with a good light. A squirt of carb cleaner up each should appear if not blocked. A blocked one may respond to a carb wire or similar from a violin or guitar.
John

[Lewes96]

Both holes clear. Just interested in the purpose of the tube and if some carbs had it while others didn’t?

[mbmm350s]

Hi
>Just interested in the purpose of the tube and if some carbs had it while others didn’t?

Never seen a VHB or VHBZ without it, PHBH carbs are different.
I just removed one from a scrap carb, a little heat was needed- PM me your address and its yours.
The installed end has a chamfer for ease of installation
actually I removed two, the first one was bent...


Cheers
Mark

[Lewes96]

Cheers, address on the way.