Leaking fuel line

Went out for a drive yesterday, but unfortunately noticed a strong smell of petrol. When I got home I lifted the bonnet and the carbs were soaked with petrol. It seems that the braided fuel line between the carbs has perished and is leaking, first soaking the braiding material, then dripping on the carbs.

My question is, I've bought some new pirelli braided pipe, so is it just a matter of taking off the old and putting on the new, or do I have to prime the carbs or something - as you can tell I am a novice and really don't want to have to go bak to the garage again!

Yes, just replace the line - I assume you got the correct size and that it is fuel grade. If it is very original then you may find that the clips can only be removed destructively and you'll need to get new jubilee clips. Also check all the other fuel lines, DO NOT wait for them to start leaking. I had one obviously leaking fuel line but when I thoroughly checked the others I quickly replaced the lot.

There should be no problem with priming the carbs - the fuel left in the float chamber should be plenty to get things started. Even with empty carbs it doesn't take long for the pump to full them up.

Thanks Cosmo - I thought it would be okay, but thought I ought to check! I bought the Pirelli braided fuel line from Classic Alfa, so hopefully that should be okay. I will check the lines thoroughly, after all the pipe is really quite cheap - certainly cheaper than 98 octane and Valvemaster Plus all over the floor .

I also bought a carb (Solex) rebuilt kit. I thought I might try do a carb clean and rebuild over the Winter. Is it an easy job, or should I best not bother!?

Originally Posted by philmiles83

I also bought a carb (Solex) rebuilt kit. I thought I might try do a carb clean and rebuild over the Winter. Is it an easy job, or should I best not bother!?

I've only done a Weber rebuild but I would guess that the Solexes would be pretty similar. Use spray carb cleaner and compressed air (like for computer cleaning) and be careful when you clear the jets - don't use anything hard that could scratch them. Should take a couple of hours.

Thanks Cosmo. I may give it a try I think. Will replace the fuel line first, and see how it's running. I'm just worried that they may be full of crap if the pipe has had a split in it for a while.
However, after speaking to Ian Ellis, apparently the Solexes are very hard to rebuilt to a non-leaking standard - it would apparently be best to replace with Webers or Dell'ortos. Annoyingly!

Originally Posted by philmiles83

the Solexes are very hard to rebuilt to a non-leaking standard

?????
don't follow this one - unless there aren't any parts available?

Originally Posted by Wrenched

?????
don't follow this one - unless there aren't any parts available?

Neither do I really - as I have bought the parts, a set from ClassicAlfa, just like the Dell'orto/Weber kits. I'll see if there's any leaking after I've replaced the fuel pipe and decide from there.

Are the Webers/Dell'ortos better carburettors?

I think it's fair to say they were more expensive - in two ways! Dearer to buy and probably dearer to feed! To be fair they might have an edge in terms of performance but I'm not exactly sure what type of Solex we're talking here. The amount of air they shift it one thing, which dependes on size mainly but also on the details of the venturi and jets but probably equally important is driveability, which is all about immediacy of response and evenness of mixture delivery. you could also say startability. The Webers on Lotus Elans I've owned, and come to think of it Dellortos on a Matra had a tendency to poor hot starting. Always OK cold. I think the latter is actually a feature of most fixed-choke carburettors and is generally tied to heat under the bonnet and conducted from the cylinder head.

Originally Posted by Wrenched

The Webers on Lotus Elans I've owned, and come to think of it Dellortos on a Matra had a tendency to poor hot starting. Always OK cold. I think the latter is actually a feature of most fixed-choke carburettors and is generally tied to heat under the bonnet and conducted from the cylinder head.

As with all things - it depends. My Webers suffer form the reverse - in cold weather they seem to suffer from a phenomenon called icing where the intake of air causes too much cooling. Leaving them to warm up under a hot bonnet fixes the problem.

Note that on the Alfa engine the carbs are isolated from the head and heated manifold by rubber.

Another thing to consider with different carbs is the setting up. Dellortos are easier to get tuned than Webers (apparently) but Webers perhaps have a slight performance edge when properly set up. I've no comparable information on Solexes.

Yes, I guess there's the inevitable compromise, too much heat in summer od not enough in winter. This reminds me of the noticeable difference in the induction systems in terms of heating of the manifolds. Milder-mannered road cars, at least when carburettors were the norm, have quite a lot of heating (via cooling system and even electric) to aid smooth running in all ambient and drivng conditions and aid emmission control eventually. Where performance was the watch-word, there was probably a lot less to keep the density of the air/ful mixture up. Interesting, I wonder since multi-point injection has become ubiquitous, if there is a difference here?

Originally Posted by Wrenched

I wonder since multi-point injection has become ubiquitous, if there is a difference here?

Something to note with modern (electronic) injection systems is that they will have temperature sensors for the incoming air and fuel. And anyway, they usually work on an air density/weight measurement to set the correct mixture which can be made temperature independent.

Originally Posted by Wrenched

I think it's fair to say they were more expensive - in two ways! Dearer to buy and probably dearer to feed! To be fair they might have an edge in terms of performance but I'm not exactly sure what type of Solex we're talking here. The amount of air they shift it one thing, which dependes on size mainly but also on the details of the venturi and jets but probably equally important is driveability, which is all about immediacy of response and evenness of mixture delivery. you could also say startability. The Webers on Lotus Elans I've owned, and come to think of it Dellortos on a Matra had a tendency to poor hot starting. Always OK cold. I think the latter is actually a feature of most fixed-choke carburettors and is generally tied to heat under the bonnet and conducted from the cylinder head.

They are Solex C40 ADDHE carbs. They seem much more happy now that I have replaced the hose - I think I drove 150 miles (or more) on less that half a tank.

I have noticed that the carb nearest the bulkhead has a few bubbles coming out on the largest gasket, so I'm wondering how easy it would be just to unscrew the carb and just relpace that one. I guess I should then get them rebalanced again.

The car seems to start absolutely fine at all temperatures - although it takes a few more turns to start when hot.

Originally Posted by philmiles83

I have noticed that the carb nearest the bulkhead has a few bubbles coming out on the largest gasket, so I'm wondering how easy it would be just to unscrew the carb and just relpace that one. I guess I should then get them rebalanced again.

What do you mean by bubbles - fuel, air or some sort of gasket compound? Which gasket is it - a manifold gasket or one joining parts of the carb together? A picture would help.

Cosmo - it's the largest gasket on the carb, number 61 on the attached image I think. The bubbles are tiny brown things, looks like air escaping through a sticky liquid. Doesn't really smell too much of petrol I don't think.

Actually this webpage gives quite a bit of info about the C40 - I guess you could compare it with a Weber Dell'orto. http://images.google.co.uk/imgres?im...3Doff%26sa%3DN

Originally Posted by philmiles83

Cosmo - it's the largest gasket on the carb, number 61 on the attached image I think. The bubbles are tiny brown things, looks like air escaping through a sticky liquid.

That gasket is on the main float chamber, there should be little or no pressure difference to the outside so it is probably just gasket sealing gunk. But that's possibly not so good - if it is leaking on the outside then there is the possibility of it leaking on the inside and bits of gunk getting inside the carb.

It makes the job of reconditioning the carbs that much more difficult. You have to spend extra time cleaning away the gunk, checking for certain that none remains inside and then figuring out why the paper gaskets were not able to seal things properly. Perhaps the previous comment someone made about never getting them to seal was true!

Originally Posted by Cosmo

That gasket is on the main float chamber, there should be little or no pressure difference to the outside so it is probably just gasket sealing gunk. But that's possibly not so good - if it is leaking on the outside then there is the possibility of it leaking on the inside and bits of gunk getting inside the carb.

It makes the job of reconditioning the carbs that much more difficult. You have to spend extra time cleaning away the gunk, checking for certain that none remains inside and then figuring out why the paper gaskets were not able to seal things properly. Perhaps the previous comment someone made about never getting them to seal was true!

That doesn't sound so good. I think I'd best keep an eye on it rather than messing with it too much - maybe the screw is just loose keeping the casing on, that would be worth a check. I think I'll save up for Webers if they start causing major problems.

Judging by your comments on economy, starting and pulling behaviour, I'd say it sounds pretty well ok.

Originally Posted by Wrenched

Judging by your comments on economy, starting and pulling behaviour, I'd say it sounds pretty well ok.

I think you're right. The car seems absolutely fine, and better than ever . Just in time to be garaged for the winter!! One weekend left of fun motoring - hopefully weather will be okay .

I keep missing nice dry days to drive to work, too easy to get into the car nearest the gate with comforts on cool dark mornings! Ours is used to going in a bag for the winter months in mother's garage; a bit out of reach.