Carburettor problems.

[David Stepney]

Spent the morning sorting out carb bits, cleaning them out and making a 'bitsa' carb with my spare body and my existing float bowl. Fitted new throttle spindle, a decent butterfly and a new needle valve (with the thickest washer of the three that Burlen sent) and cleaned everything out with carb cleaner.

SUCCESS!!!! I now have a carb that works as I would like. The tickover is about half what it was (circa 500 rpm by my estimation) and is nice an even. Took the car over the mountains to feed the horses and visit a friend at Llanrhaeadr-ym-Mochnant so did about 40 miles with no problems.

Still don't understand what is the matter with the other carb body, though.

As requested by Ruairidh, I post photos as follows:
1. Top of the carb (my spare body) numbered 26VA C (or 0) 548
2. Top of the old body (the one that was giving me problems) numbered 26VA R1634
3. Bottom of the float bowl I am using that was originally fitted to R1634 and is now on C (or 0) 548
4. Bottom of my spare bowl (which when fitted to C (or 0) 548 hunted badly and was quickly replaced by my original bowl.
5. Generic shot of 'bitsa' carb in place.

Any ideas as to what is wrong with the R1634 carb body would be most appreciated.

[Ruairidh Dunford]

Sounds like you have sorted your problem but I have labelled the photo below to show the ‘correct’ combinations of parts -

1 and 1 go together.

2 and 2 go together.

   

Do you have them like that?

[David Stepney]

Ruairidh,

Thank you for labeling the pictures. In answer to your question, they are now.

When I took the carb off, top 2 had float chamber 1 fitted. This was the carb that gave me a wild tickover. Top 1 and float chamber 2 were out of the bits box and so far as I am aware, were never actually fitted together.
Would having the wrong float chamber have given me the problem? That combination ran fine otherwise.

Body 1 and float chamber 1 are now together, as can be seen from the photos.

I hvae just got back from Blaenau Ffestiniog ( approx 50 miles return) and the car has run like a watch!

David,

[Ruairidh Dunford]

They are commonly mismatched and, when so, give the symptoms you experienced - hence my request for photos.

Glad you have it sorted.

[JonE]

Are the two bodies both '7' matched ones, Ruairidh, that just don't behave well when mixed, or is one of these of Davids an '8' carb with larger choke?

[Ruairidh Dunford]

As above Jon.

I don’t know the answer to your second question.

[Bob Culver]

Around 1950 when I was a boy my father used to regularly and meticulously check mpg on our RP, often letting it run out (which could then safely do!) Twice a year we motored 200 miles each way to visit grandparents. With two 1950s size adults and two children, driving at 40-45 as suited roads of the time used to attain 50 mpg. Later with a less obstuctive exhaust this worsened to 40 mpg. In my use, with SU and later head and driven flat out everywhere it did 38 mpg town and country.  No attempt to improve the needle.
If the car is entirely stock, not greatly overbored, and attains true 50mph on a true flat road the car (and driver) are doing well. Several contemporary road tests did not reach 50 mph.

[DaveT]

Ruairidh, What is the difference between the two float bowls as shown in the photos (Red1 & Green2) and which one is the correct one for a '35 Ruby. and why would it make such a difference in idling revs?

[Ruairidh Dunford]

Post a photo of your carb and I will tell you which bowl matches it.

There are several differences in the bowls and although they work if mixed tickover is much improved if you have a correct pair.

[Ruairidh Dunford]

The carb with two tubes here...


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Matches with the bowl that has two tubes underneath...

   

The carb with one tube here...

   

Matches with the flat bottom bowl.


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