Lister D Carburettor Strip Down

Good afternoon all

My Lister D project is making steady progress but I am struggling to completely dismantle the carburettor. I want to remove the needle valve and the screw fitting for the spring valve to check they are functioning correctly. Also, I'd like to check inside the float chamber that all is well and cannot remove the inner components. Can anyone advise me please? Pictures attached.

Many thanks.

Look under the needle valve cap and you will see  a tiny plunger which you need to push down so that the indent of the cap can pass over it then just unscrew the valve, the intake valve sits in a tube which has a thread on the outside, you may be able to undo the locking nut but the chances are the tube will fail when you try to unscrew it, be prepared to make a new one, soak it in penetrating fluid for a week, dont use WD40 it is not a penetrating fluid it is a water dispersant, the thread of the tube is Whitworth so get a whitworth screw of the same diameter cut to length and drill a hole throught the middle of the shaft and cut to length.
To remove the float squeeze the the two brass fingers and lift of the neele pin.

Maryalice

Unless absolutely necessary I wouldn't bother removing the air valve tube. As Maryalice notes it is likely to self destruct. Just clean it inside and out in situ.

PS, I thought the thread for this tube was 1/8 BSP ??? maybe I'm wrong, been there before, have the T shrt, etc

[quote="blue cat"]

PS, I thought the thread for this tube was 1/8 BSP ??? maybe I'm wrong, been there before, have the T shrt, etc [/quote]

Yes it is, it's too fine to be a whit thread.

I didnt know so assumed it was like the rest of the threads, cant be right all the time
Appletop glad youve awaken from your slumbers

Maryalice

Thank you, all of you, for your kind and helpful advice. I agree about the air valve tube - it's stuck but clean and seems to in fine fettle so I'm going to leave it alone.

The float chamber's a bit mucky so I will clean that out and the needle and reassemble.

The needle valve cap came out very easily once I depressed the plunger and as it screws in and out easily - although I can't see it moving up and down in the chamber - I am going to make the reasonable assumption that it is also in sound working order. I will clean it all up and repaint as necessary and reassemble.

The butterfly valve - controlled by the governor mechanism - moves freely so, similarly, I don't see the point in taking it to pieces.

Further thoughts and insights always gratefully received and my thanks again.

ajcooper4 wrote:Thank you, all of you, for your kind and helpful advice.  I agree about the air valve tube - it's stuck but clean and seems to in fine fettle so I'm going to leave it alone.

The float chamber's a bit mucky so I will clean that out and the needle and reassemble.

The needle valve cap came out very easily once I depressed the plunger and as it screws in and out easily - although I can't see it moving up and down in the chamber - I am going to make the reasonable assumption that it is also in sound working order.  I will clean it all up and repaint as necessary and reassemble.

The butterfly valve - controlled by the governor mechanism - moves freely so, similarly, I don't see the point in taking it to pieces.

Further thoughts and insights always gratefully received and my thanks again.

Out of interest what are you calling the needle valve cap? the turn wheel on top of the carb that you had to press the plunder down to remove and reveal the screw down needle valve. it moves up and down when you screw it in and out, thats how you set it once you get it up and running, apologies if you know that already, I maybe just miss interpreted your post.

Chris

Chris - yes, exactly that. The turn wheel which I needed to depress to fully rotate the cap. It seems in good fettle - it just needs a good clean up.

Please don't apologise, I am immensely grateful for all of the guidance, help and support that I receive here.

I do have a follow up question though, if I may?

I see on Stationary Engine Spares you can purchase a float needle retaining clip https://www.stationaryengineparts.com/Lister-D-AMAL-Carburetor-Float-Needle-Retaining-Clip-P-N-4-230.html
I am not sure my float needle/chamber has one. Does it fit on top of the float or at the bottom please?
Here is mine although I have now cleaned it up.

Apologies, I think I was being dim. The brass clip shown here does grip the needle and by compressing it the needle is released. I think all is well!

Now that the float chamber has come nicely to pieces - except the bottom nut under the chamber which I don't intend to force - I see it's a bit mucky inside. Could anybody please suggest and effective cleaning medium?

Many thanks as always.

Drop it overnight into a cup of vinegar, that's how I clean all of my carbs.

Pete.

Do not attempt to undo the nut, you will end up wanting another bowl.
Let it soak in petrol and then use a stiff brush to scrub it clean.

Maryalice