Carbs

[Barry20383]

Am thinking of having the carburettors overhauled on my 1953 Javelin has anyone any ideas of who will do the work or can i get re conditioned carbs from the club or exchange from a company .
Thanks Barry.

[David Morris]

Hi Barry,

I have used Carburetor Exchange Co. in Leighton Buzzard and had good service. I don't know if JCS do reconditioned carbs, but worth a try first?

All the best,

David

[Forumadmin]

I too have used the Carburetor Exchange Co. in Leighton Buzzard many years ago. They did a good job and importantly tested the carbs before returning. I then took to doing my own and for a few other people. But there is a lot of work and it is important to get the butterfly closing properly as well as repairing all the worn spindles. But there are often other issues such as distorted bowls. See JT for my extensive topic on the subject.

[Barry20383]

Carburetor exchange not taking on work too many orders

[Barry20383]

Am thinking of overhauling my Javelin carbs have bought 3 secondhand ones for spares. I will use new spares where possible. It seems like the choke spindles have gone can i change the ones over from the spares or change the whole body with spindles. Any ideas.
Thanks Barry.

[David Morris]

Hi Barry,

I know that when carbs are refurbished the most common problems are worn spindles and equally worn corresponding drillings in the die cast bodies.

During the refurbishment process, new spindles are fitted and the spindle housings are usually bushed and line reamed. The whole process is aimed at getting an airleak-free situation around the butterfly. Any air getting in here, other than around the butterfly, will make tuning the carbs very tricky and lead to poor idling and running.

Having said all that, there is nothing magic about having a go with your used spindles/butterfly's. You might find a combination of parts that give little or no slop in the spindles and when you hold the butterfly's closed, there should be no air gaps around the edges of the butterfly's. Bearing in mind the costs of getting carbs reconditioned, it might be worth a go?

However, when carbs are reconditioned, you get the added benefits of having all the internal passageways thoroughly cleaned, new gaskets, new floats, new shut-off valves, new jets and a check on the faces of the float chambers, to ensure they are a good fit to the underside of the castings, plus a guarantee that they are working as they should! All in all, probably worth the money!

Hope this helps,

David

[Barry20383]

Have contacted a few companies but have long waiting lists at the moment due to Covid short staff ect.
Any idea of cost. A lot of new parts are around i have seen spindle bushes and reamers for sale. The secondhand carbs i have don't seem to have any play in the spindles and bushes perhaps with the 3 secondhand carbs i have and the 2 off the Javelin i can make 2 good carbs . I can use new needle valves and gaskets ect. It depends on professional re con costs i haven't had any estimates yet so dont have anything to compare with.
Does anyone have any idea of professional carb re refurbishment prices.
Thanks Barry.

[Keith Clements]

Hi Barry.About 5 years ago I was charged £120 each.
JCS may still do service kits and do refurbs. email them.

[Keith Clements]

It was the same 5 years ago. I waited 6 months.

[Barry20383]

Have been checking the Javelin over and on checking the carbs i have found that they have slight differences.
They are both marked on the flanges 30 vm 5.
The control arms are different for the chokes and one has the connecting wire missing and doesn't have a place on the brackets to fit it. Is it normal over years for people to fit different carbs. Will the car run ok without this connecting wire between the butterfly and choke
Thanks Barry.

[nigel jarrett]

Hi Barry this is the way the cars left the factory ,the fast idle is set on the drivers side carb then transferred to the other carb via the link rod ,if you look on technical bulletins and Jowett talk there are a lot of topics on the carbs , At present I have my carbs in pieces and have found that one of the float bowl locating pegs was missing and the hole it left looked like it had broken into the idle mixture drilling so something for you to look at whilst the carbs are off

[Barry20383]

I assumed the carbs were identical on both sides of the engine and were set up the same. Thanks

[David Morris]

Hi Barry,

Nigel is absolutely correct. The carbs differ, side to side, as he describes. You will also find the one fitted to the driver's side ( RHD ) will have a drilling in the body near the butterfly for the advance/retard air feed to the vacuum unit on the distributor. The one on the opposite side has this blanked off.

Zenith carburetors were fitted to a number of vehicles during the 1950s and 1960s. After this time, there will be many versions of the 30VM-5 that look similar to those fitted to the Javelins and these sometimes crop up in auto jumbles. But beware! Zenith's stamped the carb build versions as a code on the top of the float chamber. The correct ones for Javelins should carry the number C1334 stamped into the casting. These are different to those for Jupiters, which were C1245 ( 1950 - 1951 ) and C1343 ( 1950 - 1953 ).

Hope this helps?

David

[Nick Webster]

Barry,

There is in fact an even greater variety of numbers to be found on Javelin carbs than David Morris has given. Basically though, the initial answer you had regarding the two being non identical in terms of left and right fitting is correct. However it is also important that the internal fittings specification is the same hence the numbers stamped on them. The numbers, generally speaking represent the kind of normal progression of improvements all car manuafacturers introduce as years go by.

Your forum profile says that you are not a member of the JCC. If this is so, I do not think you are able to access the technical library which is part of the forum. If you are, then look for the series of articles from JCC Australia which gives a very comprehensive outline of the Zeniths fitted to Javelin and Jupiter.

Nick

[Keith Clements]

Barry recently joined and has not updated his profile. So I did. He was already in Club Members group so can view technical docs.