Fuel dripping from carb

[paulbell6]

Morning all, not been on for a while as I have been taking the opportunity to drive the Stag whilst the weather still permits. I wonder if you could help on a problem please?
on driving the car last week there was a terrible smell of petrol (soft top down) and when I stopped and raised the bonnet the vee was full of fuel and it could be seen dripping from one of the screws on the bottom of the carb. My thought immediately went to the floats, which are new, but then shouldn't any excess fuel be discharged via the overflow tube?
Any help would be gratefully received.

thanks. Paul

[mattsay]

Hi Paul,

I am no expert, particularly on the carbs but, as you have stated that the floats are new, this might suggest recent work by you or someone else? It's always a good idea to go back to what might have been changed recently. That's stating the obvious however and won't necessarily help you now.

However, one possible cause (and I guess there could be many) is the needle valve not seating properly and flooding the carb. If you are "lucky" there could be a small piece of debris or muck (maybe when the carbs were reassembled after fitting the new floats?). One free potential fix that I have used for this (I had a similar problem recently) and one that has been suggested before (flying farmer IIRC ?) is with the engine running to pull up the knobby plunger on the fuel inertia switch and let the car starve of fuel and die and switch off. Then depress the plunger, switch IGN back on, wait for the fuel pump to stop ticking and sometimes (like I said if you are lucky) the fresh flow of fuel can clear the muck and allow the needle valve to seat properly.

I am sure there will be suggestions from good people with greater knowledge and experience, but you never know it might work, it's quick and cheap (a bit of fuel). All the best.

[Stagsongas]

Paul,

Yes, if the float valves were not doing their job and the chamber is overfilled, that excess should go down the overflow pipe if all is in order.

But....If any part of the carb. assembly is loose (say fixings, gaskets etc.) the fuel could leak out even though the chamber is not overfiled, and it would / could happen constantly. Best to get it sorted right now!

Good Luck

Steve

[paulbell6]

Thanks for the replies, yes it's a potential ticking time bomb and as such, and because the weather is bad, then it is consigned to the garage until I can get it sorted. I will try the starvation test.

thanks
paul

[Rubce]

Hi Paul

Which type of carbs do you have fitted? With or without temperature compensators and overflow pipes?

Regards

Bruce

[paulbell6]

Well I know that they are Strombergs and that's about it. The car is 1978 so mark 2. Does that help?

Paul

[Rubce]

Hi Paul

Do the carbs have a yellow plastic cover on the side? That is the temperature compensator.

Bruce

[paulbell6]

Hi Bruce, yes indeed they do have temperature compensators.
Paul

[davidf]

When you say 'screws on the bottom of the carbs', do you mean the screws holding the float chamber? In that case, either the thin cork gasket of the float chamber, or the 'O' ring in the plastic plug in the centre.

Either is a very quick and simple fix.

[stag157.7]

I see you mention new floats
I would suggest you check the correct float height setting 16/17mm ,check in the rom
also check correct orientation of the floats. seen them put in upside down many a time
as to the overflow tubes,if its flooding in the vee,check the float chamber vent valves are not stuck shut

alan

[RNF]

It could be as simple as perished fuel lines that are beginning to break down and allowing debris to get into the bowls jamming the needle valves.

[paulbell6]

Hi all thanks for your time in replying. Dave, yes it is one of the screws that holds the float chamber on, however the carbs were treated to a refurb kit with new floats, gaskets and "o" rings and the entire fuel line is only 1200 miles and 18 months old. I would like to think that these new items have not had time to perish yet - but who knows with the quality of some of the parts available.
Alan, the car went to a local carb specialist last year, you may have heard of them D and B carburettors of Nottingham, where they had the once over and bizarrely had new aluminium tops fitted, so they no longer say Stromberg on them. At that time I believe they checked the float settings so I assume that they were fitted correctly. I have been toying with buying a set of your recon carbs but the thing that worries me and is putting me off is the fact that you quote they are set for initial running, which is fine apart from the fact that I would not know how to set them up properly once they are fitted. Perhaps I am fretting needlessly, but what I don't want to do is to have to go to some one else to have them set up properly. Perhaps if you have the time you could give me a bit of a "Heads up" on the situation, but I do know by following the forum that you are a very busy man!
thanks once again for all your input?
Paul

[stag157.7]

Hi all thanks for your time in replying. Dave, yes it is one of the screws that holds the float chamber on, however the carbs were treated to a refurb kit with new floats, gaskets and "o" rings and the entire fuel line is only 1200 miles and 18 months old. I would like to think that these new items have not had time to perish yet - but who knows with the quality of some of the parts available.
Alan, the car went to a local carb specialist last year, you may have heard of them D and B carburettors of Nottingham, where they had the once over and bizarrely had new aluminium tops fitted, so they no longer say Stromberg on them. At that time I believe they checked the float settings so I assume that they were fitted correctly. I have been toying with buying a set of your recon carbs but the thing that worries me and is putting me off is the fact that you quote they are set for initial running, which is fine apart from the fact that I would not know how to set them up properly once they are fitted. Perhaps I am fretting needlessly, but what I don't want to do is to have to go to some one else to have them set up properly. Perhaps if you have the time you could give me a bit of a "Heads up" on the situation, but I do know by following the forum that you are a very busy man!
thanks once again for all your input?
Paul

HI PAUL
Firstly I did not answer your post as a means to procure business
Need to make that clear!!!!!
I will only offer some FREE advise on the forum



alan

[paulbell6]

Hi Alan, thanks for the reply. Just to say that I have been considering changing the carbs for a while now and the recent leak has accelerated that thought. Sometimes the car runs like a dream and then at other times it seems a bit flat, maybe something that new carbs will cure? Every month when the magazine arrives I hang my nose over the carb picture on your advert, and in no way do I feel that if am being sold to via the forum.
i will send you a P.M.
many thanks
Paul