Fuel injection hose size/type & are clamps necessary?

[brider]

I opened a can 'o worms with my Norge, and I'm wondering about the stock FI hoses used from the tank outlet to the......wherever that goes..and the inlets to the 2 injectors. In my case, there are NO clamps anywhere, and at barbed connections at the tank pump and injectors it looks like the hard plastic line was shrunk-onto the barb as if with a heat gun. Is this correct and is this how the connection is made?

In my insane frustration to disconnect the fitting @ the fuel tank, I said screw it and cut the line under the tank and bought a 5/16" fuel-line disconnect from an on-line source with the intent to tuck it under the tank in an open area where the NEXT time I remove the tank I can disconnect it easily. Discovered my fuel line ID is closer to 6mm (.23 in) than 5/16  .

So in a panic with the nice weather at my doorstep, I bought a 1/4" 2-ended brass barbed connector from NAPA intending to splice the fuel line where I cut it, but the existing line is rock-hard plastic and won't slide over the 1/4" barb, which leads me to think the factory condition is a heat-gun-shrink-fit.

Q: Does anyone have any experience with the hard plastic fuel lines and can verify the nominal size (1/4" or 5/16", I assume either 6mm or 7.9mm)?

Q: Is there any more conventional-type FI hose that can be used with simple clamps?

This is one of those messes you regret because it started out with an "All ya gotta do is...." activity and turns into a major PIA, but I'm thinking now I should just remove the airbox (again) and replace all the fuel lines.

[brider]

NVM - looked on-line and found Fuel Line 101 on a Hemming's site and it described the flexible rubber variety to be used with proper hose clamps like I WANT to use, and the common modern practice of OEMs using hard nylon lines shrink-fit onto barbed fitting, like my Norge.

So there you have it. Now I'll cut all the nylon lines away, measure the barbs to make sure, and order rubber line & clamps and be DONE with the PIA fuel connection @ the tank once and for all. Hopefully the barbs will all measure out to 5/16" (7.9mm) and I can use that fancy disconnect fitting I bought.

I'm sure this has been discussed ad nauseum here before, but it still helps to "think out loud" and keep the topic current.

[PJPR01]

Just in general, but many of the lines harden over time and need to be replaced.  Whether that's fuel or airbox lines or drain tubes etc...Every time I have the tank off I inspect the hoses to see if they are hardening.  I did some Oetiker clamps and simple hose clamps on some items I wanted to ensure would not come off just in case they get blown off for any reason.

The Beemer shop has the very nice connector for the fuel line, more elegant than pure barbed brass finishes if you're interested....or is that the one you're referring to above?

[Paul_Tim]

May be a silly suggestion but have you tried heating the old hoses to soften them. Recently ran into a similar problem on a kit car with hard fuel hoses, dipping the ends into boiling water for 30s or so softened them enough to allow them to slide onto the barbed fittings of a replacement fuel filter. Might not be a solution for you but I'll throw it out here anyway.

[s1120]

May be a silly suggestion but have you tried heating the old hoses to soften them. Recently ran into a similar problem on a kit car with hard fuel hoses, dipping the ends into boiling water for 30s or so softened them enough to allow them to slide onto the barbed fittings of a replacement fuel filter. Might not be a solution for you but I'll throw it out here anyway.

Ive done that also. Frankly the hard nylon stuff is not bad to work with when you get the hang of it. I replumed the fuel system on a old ford convertible I have, and while I used mostly steel, I used some of the nylon lines where it snaked through the frame at the ends.[when built ford ran the lines on the frame before installing the body] . Flexes like rubber, but much smaller in Dia to fit in tight places.

[brider]

The Beemer shop has the very nice connector for the fuel line, more elegant than pure barbed brass finishes if you're interested....or is that the one you're referring to above?

Yes, the "coupler" I bought was the same as the BS. All the previous posts I read steering me to it referred to 5/16" size, but there is NO WAY the free cut-end of my nylon line is going over the 5/16" barb, which is why I suspected a heat-shrink connection (never dealt with that before on a fuel line).

I thought of getting a heat gun, might even do that to soften the existing lines to remove them from their barbs, but I've decided to go back in with the old-school hose & clamps. I don't think clearance is an issue, but I didn't take a real close look when I had the airbox off, guess I'll take a better look the next go-round.

[Kiwi_Roy]

Depending on where the pressure regulator is on that bike you may have 40-45 psi to deal with.

[Kev m]

Depending on where the pressure regulator is on that bike you may have 40-45 psi to deal with.

It's pretty rare for a pressure regulator to be anywhere but integrated into the fuel pump unit on bikes. I feel like the Tonti Calis were a weird exception for a while but even that was decades ago.

[brider]

Depending on where the pressure regulator is on that bike you may have 40-45 psi to deal with.

Regulator must be in the tank as Kev says, it's just straight hose from tank disconnect to a T-fitting then out to injectors @ the manifolds. Measured the barbs and it looks like 5/16", removed plastic line has euro lettering and a 8/1 indicator on it, almost sounds like 8mm ID/1mm wall, which equates to .314" ID, pretty close to .3125". Gonna pick up hose & clamps today and button it back up.