Hi James,
Fuel leaking from the joing between the float bowl (pot) and jet line is a
common proble on SUs. What is supposed to happen is that the brass nut on the
end of the tube that you can pull out is supposed the tighten down clamping the
end of the tube (which should have a small metal tube inserted into it) onto an
'o' ring in the hole in the float bowl.
What tends to happen is that the O ring gets knackered, or lost, or in some
cases a second one is put on tome of an old one. All these cases lead to fuel
leaks.. To solve this, undo the brass nut and fish out the old o ring and any
others hinding there and replace with a new one. You can buy new ones from
Burlen SU supplies. While you're waiting for this you can always try swapping
the O rings from the old carbs and see if they work...
What is a little more worrying is that the non-leaking pipe has no fuel in it!!
Perhaps it would be leaking if it did have fuel in it..
Both pipes should be full of fuel when you turn off the car..
Is the lean running carb the one with an empty pipe?
If it is this explains why it is lean..
Two possibilities,
1) the fuel pipe from one carb to the other is blocked.
2) the o ring I was talking about for the first carb has been twisted 'round in
the second carb blocking fuel flow from the float bowl to the jet (Don't ask
how I know, it was a long story)
It is amazing how well you can get a spit to run on one carb...
Hope this helps
Cheers
Tim
James Carruthers wrote:
> I fitted the new carbs and the K&N airfilers yesterday. Stupidly not checking
>the assembly I dumped 1/4 tank of fuel up the road - and only just managed to
>get the car back to the garage. This was the first time Ive ever broken down -
>in any car. It was quite scary. However we tightened up fuel line between the
>carbs (it goes around the outside of the air filter) and it was fine.
>
> We balanced the carbs as best we could - and the car seems much better.
>however one of the carbs doesnt want to go any leaner. I think it may have
>something to do with the jets being uneven. However it runs fine - and I drove
>home from my uncles (who helped fit it) late yesterday evening (40miles) at
>motorway speeds. When I parked the car I noticed the fuel had been used up
>slightly more than I thought it would be. And a slight smell of petrol was
>also present. However seeing as I had smelt so much petrol that day I thought
>nothing of it.
>
> I returned this morning to the car and decided to check it over before
>setting out to college. So I checked the oil and water - that was all ok -
>though the oil needs doing. I decided to start her up with the bonnet open.
>However its started leaking fuel. Its dripping (only on one side - the rear
>carb towards the cockpit) where the small fuel line between the float tank (im
>not mechanical sorry - Im pretty sure thats what its called - the cylidrical
>part that actually says SU Carb etc etc) and the pot (the lower part) - I can
>easily pull out the pipe (flexible plastic with metal sprial piece of metal
>outside it) - but I tried it out on the old carbs and it comes out too. I
>tried tugging the pipe on the other side - but couldnt exert enough force for
>it to come out. I didnt want to break it! I also noticed that the pipe was
>full of fuel when I turned off the ignition - where as the properly working
>non-leaking pipe was empty. I imagine it isnt sucking up the fuel.
>
> Antoher problem may be the spark plug leads - as I know I need to replace
>them ASAP. Any connection? - it happens to be the offending lead it on the
>same side as the leaky carb.
>
> I still have the old carbs - so I could have a stab at changing them back - I
>saw them being changed yesterday - but really I dont fancy trying it. Of
>course I cant get hold of my uncle for the next couple of days either.....
>
> Being stuck with out my motor is a very sad feeling :(
>
> james
>
> 77 Pimento Red Spit - Not working :(
>
>
--
Tim Dafforn
University of Cambridge
Structural Medicine Unit
Cambridge Institute for Medical Research
Hills Rd, Cambridge CB2 2XY.
UK
Tel. (01223) 763230
Fax. (01223) 336827
http://smokeroom.cimr.cam.ac.uk/
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