Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Fuel hose, clear plastic or black rubber

Was there a year when BSA changed from black rubber to clear plastic if indeed they did it at all? What about Triumph?
Sid

A sales brochure for 1953 shows black rubber, one from 1955 shows clear plastic.

I do not have a brochure for 1954, so if one of you guys has one, the answer may be in the pictures in that one.

Most if not all BSA's I have seen have black fuel line and Triumph mostly used clear fuel line.

Ferrule crimping styles are also different between the two and fuel sizes (ID & OD)

Unless you are really keen with originality, I would use Tygon fuel hose, which despite being a translucent yellow colour, appears to remain flexible for years, doesn't turn brown and become brittle.

Both black rubber and clear plastic are unsuitable for fuel hose long term. The petrol rots the rubber which then blocks the carb. Petrol hardens plastic hose causing leaks at the fittings.
The black synthetic rubber used on Japanese bikes lasts well as does the yellowish Tygon hose

Fuel lines last about 5 years tops for me, thats the black rubber stuff, it starts to crack on bends eventually. Especially where UV gets it. Never tried the dayglo stuff. Sounds great.
Havent used clear stuff for years , it gets too brittle.

I use clear thickwalled polyurethane made for ultralight aircraft stays flexible for a very long time
https://www.air-techinc.com/maingroups.php?pmid=12

What's the consensus on black fuel line when you don't have to buy ethanal fuel? In these parts, we have more than one choice of non ethanal including Chevron 94 and haven't had a problem yet.

Cheers, Wilf

I've been using plain ol' double-walled automotive fuel hose for around 40 years, and I've never noticed any swarf in the float bowls (and I run Mikunis, which have no inlet screens).

But, I change hose frequently, I'd say every 1-2 years. At $.35 per foot at the auto supply store, why not?

BTW, if you don't like the writing on the hose, a little acetone or alcohol will take it off.

I like Clear. Superthane TM is the best.

+1 clear. You can SEE it tickling (or not).

That's interesting. We use Tygon for oil compensated lines on the deep water ROVs. They get exposed to plenty of UV on the back deck of the ship and massive pressure at thousands of meters depth, but I've never seen one give out.

Josh, where would one acquire Tygon hose? And, what is an ROV?

Remote Operated Vehicle" used to get oil, cheaper than divers.

You can buy Tygon tubing on eBay, Amazon etc.

There are various formulations around but the one you want is the yellow petrol resistant type, should be marked F4040A, see .This Link from the manufacturers website.

Watch out for fake Chinese copies.

UV light attacks everything and causes them to degrade, people included.
Keep your bike out of the sun & the fuel line will remain soft for a very long time.
Heat also does the same thing
So never ride your bike and the black rubber fuel lines will remain soft for a very long time.

There are many different grades of black rubber fuel line.
The best is a double layer one with butyl ( petrol proof ) rubber inner sleeve and a neoprene ( oil resistant ) rubber outer sleeve.
These come fiberglass reinforced, steel reinforced , stainless steel reinforced & I have just seen some kevlar reinforced ones.
The strongest are the fuel injected hoses.

As such a lot of fuel line can crack on the outside & not leak.
Then there are single wall rubber fuel lines, the best are Bunya-n rubber but the down side of them is when they start to crack on the outside the crack will go all the way through.

While it is a PIA to replace them, only properly spiral wound, full soft copper fuel lines are permanent so everything else should be considered a service replacement part.

Tygon, made by St Gomain in the USA is the yellow coloured fuel line.
They also make a clear , a grey & a blue fuel line.
The tygon is a single wall tube so when it starts to crack it must be replaced.
Tygon s very expensive & as already mentioned will have the manufacturers code as a continious line for the full length of the tube.

I fix lawnmowers & get a lot of spam selling unbranded fuel line in the "Popular yellow colour"
Most of this is gelatin based plastic and will dissinergrate while you are riding.
A lot of cheap Chinese chain saws come fitted with it as standard and they all fall apart within a year or so.
many stories about exploding shainsaws & line trimmers from this line leaking and then the tool bursting into flames.

Genuine Tygon is expensive.
If it is not expensive then it is not Tygon

Some BSA's came fitted with plain old PVC which will also work, but goes hard in a few years thus requiring regular replacement.

It is your bike so you decide what you want to fit, just remember no matter what you use it WILL HAVE TO BE REPLACED at some regular interval.
The cheaper the tubing the more often you will need to replace it.

I recommend against copper fuel line. It breaks.

I have good success with black rubber hose sold as car fuel injection hose.

Yes. Copper "work hardens" with vibration and then breaks.

A loop turned someplace along the copper line can act as a "spring" to prevent this, IF there is room for such a loop.
Old knucklehead and flathead Harleys had just such a loop in the fuel line for this reason.

I wouldn’t be at all surprised if coiling the pipe helps.

I doubt that it helps enough.

a better use for coiled copper

Ever wonder why copper is not used on brake lines?

Nope.

https://www.ebay.co.uk/i/252333471572

Wow I didn't know they used it for brakes anymore. I thought it was illegal at least on this side of the pond. With vibration copper work hardens and breaks, at least that's what a couple of brake shops told me. But what do I know I'm just a backyard mechanic and I've never had to replace brake lines.

The so called copper brake pipes are not copper but copper/nickle alloy.
Stamping on the brake pedal can produce brake line pressures of over 2000psi, copper would not stand a chance

It’s still as ductile as copper.

It’s far superior to what the manufactures use on cars which is steel pipe with some kind of coating on there. When that stuff corrodes it’s pretty frightening, snaps like a weak twig when replacing the lines if its bad enough.