SU CARBURETTOR FLOAT CHAMBER FLOATS

[ALAN COCHRANE]

Hi Everyone

A different subject this time! Once the interior refit of my 1962 OTS is complete I'll be turning my attention to the carburettors. All three float chambers appear to overflow in varying degrees. The problem is most likely the floats or needles valves, or both.
I see that SNG list both a brass and plastic float. Cost wise there's only a pound in it. I also see somewhere else in the Forum someone mentioned foam floats.
Can anyone recommend any one over the other two and where can you buy the foam floats?

Cheers

Alan

[christopher storey]

Trouble with floats is not as common as sometimes is made out. The only thing that really can go wrong with a float is that it develops a puncture and leaks. There are two easy test for this - first , with fuel in the float chamber, extract the float and shake it . If it has a leak , it is virtually certain that you will be able to hear something inside it if you shake it. The other test is to put it in very hot water and submerge it - again, if it has a leak you will see a stream of bubbles emerge from it

Far more likely , particularly if the car has not been used for a year or two, is that the needle valves are sticking. They get gum on them . Dismantle them and thoroughly clean them in a solvent such as redex. Examine both the needle and the seating under a strong magnifying glass. If you can see a circular wear mark on either of these then it is time to change the valve and seat ( Burlen Fuel Systems) , but otherwise after a thorough clean they will probably work perfectly well

[ALAN COCHRANE]

Christopher

Yes I would agree that the needle valves are just as likely to be the culprits. I've had to replace both these and the floats in the SUs on my Triumph GT6.
I was really trying to find out which of the three float options-plastic, brass or foam was better, if it turns out they are the problem.
Any advice would be gratefully received!

Cheers

Alan

[PeterCrespin]

.
I was really trying to find out which of the three float options-plastic, brass or foam was better.....Any advice would be gratefully received!

How long is a piece of string?

You'd have to define 'better'.

Prettier? Cheaper? Better value? More reliable? More durable? More original? Greener? etc.

Pete

[christopher storey]

I still like the brass floats, but it is said that as fuel with higher and higher evels of ethanol is introduced, this will attack brassware in the fuel system . How accurate this is , is open to question, as my preferred fuel in the 1960s was Cleveland Discol which was about 15% ethanol, and never gave me trouble . I have never had trouble with plastic floats either but they do not look as nice ! The foam ones, to me, are a solution to a problem which I have never had in over 1.25 million miles of motoring !

[ALAN COCHRANE]

Christopher

I see you mention the foam floats. I have been told that these were originally made for military vehicles to overcome the plastic float's tendancy to puncture and let in fuel.
Is this the case and if so where did you buy your's from?

Cheers

Alan

[christopher storey]

Alan : sorry, my post must have been ambiguous - I have never seen the need for foam floats, but if you want them they are available ( at a price ! ) from Burlen Fuel Systems and probably from the usuals also

[ALAN COCHRANE]

Christopher

Sorry I had misread your reply. I've checked Burlen Fuel Systems and see they're offering a foam alternative. First off, I'll have to see what diameter float fits the 2" SU's-I should know this. I'm still undecided as to which to go for.
I appreciate your info about the brass floats, I think it'll be a straight choice between plastic and foam, although the foam floats are about twice the price.

Cheers

Alan