S u carb

[Classiccars]

Hi all sorry haven't a picture of my set up but can you please advise whst is the cylinder show here next to the su.I have similar on the twin set up .Only one but sits near the su with pipes on and out and the gasket at the top is leaking thanks.

[svenedin]

Sorry I don't understand. Did you mean to post a picture?

Stephen

[les]

Bit of guessing game, is it the float chamber !

[svenedin]

Bit of guessing game, is it the float chamber !

Could be! It's easy to buy the gasket and only 3 screws to remove to change the gasket. Just be sure to use a screwdriver that fits well and has a large enough blade. It looks awful to see chewed up screw heads.

https://www.morrisminorspares.com/fuel- ... 59-p830622

It does rather suggest that the float bowl is overfilling if it is leaking from the gasket.......

Anyway, this is pure guesswork at the moment.


Stephen

[myoldjalopy]

Guessing that it is the float chamber, if it is leaking badly it may be that the float has developed a leak. The old metal ones are particularly prone to this after many decades.Once I was driving and noticed a sudden smell of petrol. I stopped and saw that the float was leaking, removed the lid and saw the old float has sunk to the bottom. Wondering how to get home, a passing motorist sympathetic to old cars stopped and when I told him I had a spare in a carb in the garage, he kindly took me home, where I got the spare float out of the carb and we then back to the car with the spare so I could fit the float. It was only about four or five miles in all but I was very grateful for his help

[geoberni]

Yes, but he says .....

Hi all sorry haven't a picture of my set up but can you please advise whst is the cylinder show here next to the su.I have similar on the twin set up .Only one but sits near the su with pipes on and out and the gasket at the top is leaking thanks.

I don't know of any Twin SU set up that only has 1 Float Chamber; to the best of my knowledge the Twin setup is just 2 complete Carbs, left and Right handed, with a float chamber outboard of each, and common connecting rods between....

Like this example:

If Classiccars can work out how to post a photo, or a link to another one on the internet somewhere, we might be able to help...

[les]

Yes, I noticed that but then he goes back in the next sentence regarding the issue with the one carb, although the post is very confusing. It’s a rather ambiguous account.
Let’s hope it is the float chamber after all the explanations, maybe the OP will post a plcture. Another clue for him, or indeed for us. Is this ‘cylinder’ actually part of the carburettor? ie fixed to it ? We await the update !

[Classiccars]

Thank you for the replies on Limited info.It was an after thought as garage is a Mike away.I believe you are correct on being a float bowl as the proposed gasket looks correct.Will try yo post a picture at some point but if it is a float issue can I easily get another and fix on with Limited knowledge please.

[geoberni]

It depends what you find.
It might just be a torn gasket.
It might be a leaking float.
Mine was leaking because in a million to one (or greater) freak event, a grass seed got into the fuel line while I had it open.... and was lodged in the valve. It didn't come through the pump filter, nor the paper filter that I have between the pump and the Carb.
I got it out with some tweezers and problem solved.

20240812_125603.jpg (549.1 KiB) Viewed 92 times

Edited to correct a typo I just noticed.... does anyone else ever read back their own post when looking at subsequent comments...

[svenedin]

The float is quite easy to replace. All you have to do is pull out the hinge pin and swap the float over but you then need to set the correct float gap or otherwise the float chamber will under or over fill. It is probably silly to just replace the float without replacing the needle at the same time. That too is easy. If the needle seat is worn this too can be replaced but it needs a special thin-walled BA box spanner. The float bowl can over fill for a number of reasons. Wrong setting, float is sinking due to a hole in it, worn float needle and/or needle seat. The modern floats are black “stay-up” made of a special foam that cannot sink. Modern float needles are Viton tipped to resist ethanol.

Stephen

[Classiccars]

Great advice as ever.