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Stainless Braided Fuel Lines - A Warning

While sitting outside Costa Coffee in Bourne End last weekend, enjoying the company and the sunshine. I noticed my Commando parked about 5 feet away was leaking fuel. I had just put 5 gallons in the tank so this was somewhat worrying.

On close inspection I saw two fine jets of fuel spraying out from the left hand fuel pipe about two inches below the fuel tap. It was lucky that it was on the side stand as the spray was missing the rather hot exhaust.

My fuel pipe is a stainless braided one from RGM, now 8 years old and looks as good as the day I bought it. I chopped the pipe a couple of inches below the leak and plugged the end going to the carburetor with a solderless nipple and rode home.

Once home I removed the braiding from the first 4 inches and found the rubber pipe was showing definite signs of decay. If you look at the attached picture you can see some cracks and pinholes.

As I say, the pipe looked as good as new and I am just glad I was sat in view of the bike. This may explain my rather high fuel consumption recently. Maybe old age (8 years ! ) or Ethanol but whatever it is, I will not be using fuel pipe again where I cannot see the condition of it. I have ordered some of the Tygon pipe Dave Evans recommended elsewhere.

Tony

Attachments fuel-pipe-pinhole-jpg
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Mine was a few years older but went the same way last year, have gone to stainless fittings but plastic braided pipe renewed when it goes which is not long.

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Hello gentlemen- I don't know if ethanol is added to petrol in the UK but here in the USA it is and it causes numerous problems including the breakdown of non metallic components in fuel systems.

Failure of clear plastic fuel lines of the type that is made by wrapping the plastic around a mandrel in a helical fashion and fusing the seams is quite common . To look at this material when new it appears to be seamless . After a few years exposure to ethanol the helix starts to show and ultimately begins to leak .

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Eth is in most UK fuel ,but is is just possible to avoid it. I have had several car/bike pipe failures and seen heavy corrosion to alloy chambers. Interestingly the black plastic fuel pipe on my 1960 Norton is still in place!,although now very hard/brittle.

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Makes me think I should check the fuel lines of my 15 year old Toyota, however problems with fuel lines appears to me more common with bikes than cars why is that?

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Gentlemen,

Similar story with my Commando. Back in 2014, fitted SS braided lines (from NorVil), interior black plastic tubing was of an unknown material and allegedly used with 100% non-ethanol fuel that was available at the time. This failed in the same manner as described in this posting after only a few hundred miles, fortunately in the garage at home. I spoke with fuel specialists from two major oil / fuel suppliers at the time (big ones too) who âoff the recordâ told me that different climatic conditions / winter / summer blends happened too with and without Ethanol. This was further exacerbated when I went to take my elderly K-75 BMW out of mothballs in 2016 and found that the fuel had disintegrated the elastomer / rubber anti-vibration fuel pump mount (fuel pump and hardware live inside the fuel tank and consequently all associated components are submerged most of the time in whatever fuel you place in the tank). After spending two + days scrubbing & flushing the tank and fuel system, including servicing injectors etc. trying to locate a fuel line that was accredited to live inside a fuel tank was a challenge I can tell you. In the end bought an after-market complete fuel system kit from the USA and all has been well ever since.

Anyway, all quality flexible car fuel injector pipe work, for example a Codan product, but there will be others:

https://www2.codan.com/node/28273

The inside elastomer is compliant / fuel resistant to modern fuels, which is perfect for gravity fed motorcycle fuel line. Only downside is its opaque but inexpensive and easily available from quality outlets. I have used this exclusively on all my gravity fed bikes since with no issues. So please be careful a fuel fire while out riding is not going to end well.

Rgeards

Steve

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+1 for using Tygon fuel lines.

If you don't like the widely available yellow or black colours, Motion Pro due a clear version although price varies a lot.

I use this with Oetiker double-ear clamps to secure the tubing.

Works fine. I've only used for just over 3 years but the tubing remains clear, pliable and is not at all brittle or showing any signs of deterioration. I do prefer to be able to see what's going on with the petrol in the lines.

Andy

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My original ?53 Dominator, owned more than 60 years ago, had copper fuel pipe. My usual fuel was Cleveland Discol (10% alcohol), and, there were never any problems. I now run a ?54 model, which is happy to run on almost any fuel (95 octane or over) I put in the tank. Still no problems! I now use clear plastic fuel pipe (supplied by RGM). A possible useful addition is an in-line filter, of the type used on outboard motor fuel lines, fitted directly below the fuel tap.

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I have had this happen twice on my 1974 Chevrolet Camaro when I have used so called Earls or Goodrich type stainless steel covered hoses. I fitted a new clear petrol filter, and put the old stainless steel covered hose back on. Started the motored poped the bonnet and the petrol was gushing out of the bend in the fuel pipe. I would not have known this was happening as it was out of sight unless I had checked. I was told when I bought this fuel hosethat it was ethanol proof from a trader at Kempton Park. I had some of the pipe that was Stainless Steel covered on my Nomads Amal 276 carbs, and it started to really pour out of the fuel pipe. The rubber fuel pipe had cracks through out it length, so I changed them to a proper ethanol proof fuel pipes from AMC Classic Spares.

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Previously John Shorter wrote:

My original ?53 Dominator, owned more than 60 years ago, had copper fuel pipe. My usual fuel was Cleveland Discol (10% alcohol), and, there were never any problems. I now run a ?54 model, which is happy to run on almost any fuel (95 octane or over) I put in the tank. Still no problems! I now use clear plastic fuel pipe (supplied by RGM). A possible useful addition is an in-line filter, of the type used on outboard motor fuel lines, fitted directly below the fuel tap.

I also doubt that ethanol per se is the problem and agree with you about Cleveland Discol (although I'm too young to have used it, my father swore by it for his Nortons and Morris 8). I always use proper black synthetic rubber fuel lines as there is no telling what's inside the braided stainless ones. For example:

https://www.halfords.com/workshop-tools/garage-equipment/fuses-electricals-fixings/halfords-fuel-hose-8mm-hfh402

The writing on this can be removed with cellulose thinners.

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Previously Tony Ripley wrote:

While sitting outside Costa Coffee in Bourne End last weekend, enjoying the company and the sunshine. I noticed my Commando parked about 5 feet away was leaking fuel. I had just put 5 gallons in the tank so this was somewhat worrying.

On close inspection I saw two fine jets of fuel spraying out from the left hand fuel pipe about two inches below the fuel tap. It was lucky that it was on the side stand as the spray was missing the rather hot exhaust.

My fuel pipe is a stainless braided one from RGM, now 8 years old and looks as good as the day I bought it. I chopped the pipe a couple of inches below the leak and plugged the end going to the carburetor with a solderless nipple and rode home.

Once home I removed the braiding from the first 4 inches and found the rubber pipe was showing definite signs of decay. If you look at the attached picture you can see some cracks and pinholes.

As I say, the pipe looked as good as new and I am just glad I was sat in view of the bike. This may explain my rather high fuel consumption recently. Maybe old age (8 years ! ) or Ethanol but whatever it is, I will not be using fuel pipe again where I cannot see the condition of it. I have ordered some of the Tygon pipe Dave Evans recommended elsewhere.

Tony

Dave passed on a lot of usefull tips.

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I've been suffering with E-10 for many years/decades. Especially when used in OPE. (outdoor power equipment)

E-10 is hydroscopic and the moisture will corrode some metals especially zinc based carbs (amal is one).

E-10 is nasty for variaties of plastics and rubbers. However the word tygon represents only the PVC family made by saint-gobains, swiss owned company. They make many many many blends many of which are no good for E-10.

Tygon F-4040 is very good for E-10 fuel. There are a few other blends but are much stiffer. According to the engineers I spoke to at St Gobains USA F-4040 blend is a dual layer of ethanol resistant liner with a cheaper outer cover that is NOT E-10 resistant and makes it unsuitable for some OPE equipment, primarily where the line goes inside the tank.

IMO If persons recommend tygon without a formula or blend #, then they have no credibility.

real tygon is always imprinted with the blend on the outside. There are plenty of fakes out there.

F4040 I used on my MKIII commando from rebuild in 1995 and was flexible when renewed around 2015.

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About 25 years back my then 8 year old Vauxhall 2200i (fuel injected beast) started leaking through all the high pressure fuel hoses. They all had to be replaced. No ethanol was involved. Modern fuel injected cars run at high pressures so presumably any current fuel hose from a reputable dealer should be safe. Whether that includes stand holders at autojumbles I don't know but I have my suspicions! Later and now older cars haven't yet given problems.

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Previously David Comeau wrote:

I've been suffering with E-10 for many years/decades. Especially when used in OPE. (outdoor power equipment)

E-10 is hydroscopic and the moisture will corrode some metals especially zinc based carbs (amal is one).

E-10 is nasty for variaties of plastics and rubbers. However the word tygon represents only the PVC family made by saint-gobains, swiss owned company. They make many many many blends many of which are no good for E-10.

Tygon F-4040 is very good for E-10 fuel. There are a few other blends but are much stiffer. According to the engineers I spoke to at St Gobains USA F-4040 blend is a dual layer of ethanol resistant liner with a cheaper outer cover that is NOT E-10 resistant and makes it unsuitable for some OPE equipment, primarily where the line goes inside the tank.

IMO If persons recommend tygon without a formula or blend #, then they have no credibility.

real tygon is always imprinted with the blend on the outside. There are plenty of fakes out there.

F4040 I used on my MKIII commando from rebuild in 1995 and was flexible when renewed around 2015.

I slightly object to your statement:-

IMO If persons recommend tygon without a formula or blend #, then they have no credibility.

Dave Evans was, and certainly I am, perfectly capable of looking on the Saint Gobains site and determining which pipe is recommended for Ethanol adulterated fuel. Yes it is F4040.

I would hope that any other member reading this would be able to do the same.

I bought fromhttp://www.pvctubeonline.co.uk/tygon_fuel_tube.htm

Tony

 


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