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Maintenance of Fuel Lines

Posted: Mon Jan 11, 2016 9:07 am
by D-Rider
The Falco has fuel lines both inside the fuel tank and between the tank and the throttle bodies.

Aprilia's guidance is that they should be inspected every 8 months and changed every 4 years.

I expect that few have followed this guidance.

Reports on other forums suggest that poor hose condition can lead to poor starting and poor running.

Also, the Falco was designed before Ethanol was commonly added to fuel and I'm sure most of us would be happier if we knew that our fuel lines were resistant to ethanol.

There is now a thread in the technical section that covers what I have researched in terms of replacing the fuel lines (internal and external) and also in adding a QD coupling to the fuel delivery line.

It's currently a fairly comprehensive short cut to gaining the information you need to do this job but it is not an instruction manual.

Anyway - here's the link: https://www.ridersite.com/viewtopic.php?t=13082

If you have comments or suggested additions to that thread, please post them here and then I'll update the thread.
It's already quite long so maintaining it in a fashion where it can be easily read will be a challenge.

Posted: Mon Jan 11, 2016 11:13 am
by Dalemac
Thanks for the write up Andy.

I actually did this last summer - pretty much identical to what you have explained.

Image


Only things I would add, are:

Buy more fuel line than you need - It's cheap enough to buy and too easy to cut too short.

Extend the hoses ever so slightly from standard, just a few extra centimetres makes it easier to lift the tank.

By far the hardest part of getting this correct was resealing the hose on the fuel pump base plate. Buy plenty of washers, and make sure they are the correct size/thickness, and metal.

Quick connectors - I strongly suggest you use the brass ones and not the plastic ones. I couldn't find plastic ones that were rated to 4 bar pressure, which is what the fuel pump runs at.

Give real thought to the placement of the quick release connectors. They are best when staggered slightly, as shown in the image above.

Seals on quick connectors MUST be VITON, as they are fuel resistant. I had nitrile seals on mine to begin with and one swelled and leaked within 24 hours.

And finally, don't rush this job or cut corners - the last thing you want is your bike going up in flames, especially with you on it.

Posted: Mon Jan 11, 2016 11:40 am
by D-Rider
Hi Dale - and thanks for your comments.

I agree that the plated brass couplings are probably more robust but they are fearsomely expensive.
The CPC Acetal ones I have found seem to be rated to 8.3bar - and CPC give a write-up on how they worked with BMW fit a pair of them to their bikes - so I'm hopeful that they will be OK as long as they are not abused.
I'll keep an eye on the ones I'm fitting and swap them over if they don't work well.

I'm glad to get your comment on Viton and Nitrile as there is so much conflicting info on their relative performance for this application.
I came down on the side of Viton and your experience seems to confirm it.

Posted: Mon Jan 11, 2016 11:57 am
by Falcopops
good work Andy, thanks for your efforts and info

Posted: Mon Jan 11, 2016 12:59 pm
by Dalemac
The way I justified the price of the brass fittings was the lack or reliability of the plastic ones - with so many people reporting repeated failures I decided i'd rather buy them once and know that I could leave them fitted for the next 4-6 years and not have to worry about them.

Posted: Mon Jan 11, 2016 1:55 pm
by D-Rider
Dalemac wrote:The way I justified the price of the brass fittings was the lack or reliability of the plastic ones - with so many people reporting repeated failures I decided i'd rather buy them once and know that I could leave them fitted for the next 4-6 years and not have to worry about them.
Yes indeed - I have no quarrel with your decision or reasoning.

As you might see from my write-up, I've changed the hose size on the delivery side so that I can fit the brass ones if I need to - but will try the acetal ones first (and keep a good eye on them).
I have enough confidence to try this out given that Mangocrazy has done this on his Falco and CPC have developed them for BMW - so although I've got an easy upgrade path if I need it, I'm hoping the Acetal ones will do the job.

Posted: Tue Jan 12, 2016 11:04 am
by mangocrazy
Very timely, as I'm just about to fit QD connectors to the Red Falco's fuel feed line. The blue Falco had this done (as Andy says) a couple of years ago, using acetal CPC fittings, and I've had no problems. Aprilia use acetal fittings for the QD return line, so I didn't really see a problem, plus I've used them on my Ducati for the last 15+ years.

I'd definitely second Dale's comments re; Viton seals vs. nitrile. They are superior in every way as far as I can see - greater temperature resistance and excellent Ethanol tolerance for starters compared to nitrile. Also agree about making the hose a little longer. Manufacturers cut corners in areas like this.

I'd also recommend giving the O-rings a wipe of silicone grease before assembly. This makes the fittings slide together much more easily and guards against abrasion and tearing when joining the two halves. Do this every time the fitting is undone.

I am interested to note the size of hose you're using, Dale. I replaced mine with 5/16" (7.9mm) as that was the size of hose barbs on the banjo fittings and QD fittings I bought. As long as everything matches up it doesn't matter of course. 6mm hose will flow plenty enough fuel.

I managed to get hold of some Gates Barricade fuel injection hose from the USA (courtesy of my sister-in-law) that is SAE J30 R14 rated. We simply don't seem to be able to get stuff of that quality in the UK, unfortunately. It's rated up to 225psi and has exceptionally low 'leakage' rates for fuel. It's not widely known that ALL fuel hose will pass a certain amount of fuel as vapour through the hose wall. The trick is to try and minimise that.

Lastly, I prefer using single or double ear Oetiker clamps to fix the hose to the banjo/QD fitting barbs. Using Jubilee clips inevitably bites into the hose to some degree and can damage it. The Oetiker single ear clamps I use have an internal sheath that slides round the surface of the hose as the ear is clamped, protecting the hose from damage. These are the puppies:
http://www.tom-parker.co.uk/products_su ... oups=4145A

Posted: Tue Jan 12, 2016 11:24 am
by mangocrazy
I hadn't read Andy's thesis in the technical section before making my reply - excellently researched and annotated, if I may say so. That must have taken hours to put together. It's more like a research paper for peer review than a forum post... :smt003

Posted: Tue Jan 26, 2016 9:23 pm
by DavShill
Crikey Andy, that's a bloody masterpiece. I shall certainly refer to these posts if I ever pluck up the courage to do the job myself. I suppose I should considering the bike is now approaching 11 years old. It's due a service and tune up. Might have a run to Griffs.

Posted: Tue Apr 12, 2016 2:30 am
by Tipper2
Hi,

Thanks for taking the time to post this.

I noticed my original braided hose is badly kinked and you've saved me a lot of time.

Posted: Tue Apr 12, 2016 6:44 am
by D-Rider
Tipper2 wrote:Hi,

Thanks for taking the time to post this.

I noticed my original braided hose is badly kinked and you've saved me a lot of time.
Glad to have helped.
I've actually fitted mine now so I know it all works fine.

Posted: Tue Apr 12, 2016 11:06 pm
by Falco Frank
Very timely and excellent article on the fuel lines and filter.

I siphoned my tank dry yesterday to get rid of the treated fuel prior to a service. The fuel lines look good but I just realised I've never changed my fuel filter in nearly 7 years of ownership! Cant believe I forgot it, I knew it was in the tank too...

On a side note, my Ducati has a metal bodied fuel filter too that I had sufficient space under the tank to be able to move it out and make it external.

I simply replaced the two sections of hose with one and cut into the delivery hose along the line.

Not sure there is space on a Falco to be able to do this but going into the tank does not look to be as much of a pain as it is on a Ducati!

Cheers

Oh yes, I'm also seeing flaking on the plastic upper walls of the tank, Ethanol I'm guessing?

Posted: Fri Apr 15, 2016 11:02 am
by Falco Frank
A good supplier of fuel hose that I have used in the past....

http://www.ebay.co.uk/itm/Inside-Tank-F ... 1012073753

Posted: Fri Apr 15, 2016 11:23 am
by D-Rider
Falco Frank wrote:A good supplier of fuel hose that I have used in the past....

http://www.ebay.co.uk/itm/Inside-Tank-F ... 1012073753
Yep - already there in the list of links in the main thread on the subject.

Good to have it confirmed though. :smt004

Posted: Thu Jun 01, 2017 12:15 pm
by Firestarter
So... having sat on this for a long time, it's finally time for me to get round to fitting my new tank.

Only bit I'm not sure on are the clamps. Looking at the Oetiker 167s that are recommended, does anyone know what size they should be for the standard hoses? Looked at an Oetiker data sheet, and I'm confused. I'm assuming a hose diameter of 14.5mm (based on Andy's description in the link above), which would be larger once on the spigot, so which clamps are needed?

Thanks