Fuel lines dimensions

[Siloxious]

Hello everyone, Deltarider gave me the following advice about fuel lines:

1.Verify fuellines have the right dimensions
The CB500/550s are very sensitive for a proper fuelflow route, so let us first establish whether everything is standard or not.The correct dimensions for the fuellines are: for the CB500 and earlier CB550s: 18 and 30 cm length for the models with the bowltype petcock and 17 and 28 cm for models that have the newer style petcock. Do not be tempted to have them longer. For the tube that supplies carbs 3+4, use the soft metal clamp in the middle front side as shown in the pic (btw, horizontal is good enough) for proper routing. Ideal inside ⌀ of the fuel lines is 5,5 mm. Outside ⌀ will be around 10mm. Have this and the lines will not kink. Abstain from extra inline filters. Some have been lucky with them, but my experience is they can't be trusted. Often it isn't that filter itself, but the rerouting of the fuel line that - sometimes intermittent - impedes a proper delivery of the gas.

I am living in Belgium, and I've been looking everywhere for these dimensions, but I can not find them.
Can I also use inner diameter 5mm and outside 10mm? (or for example inner diameter 6mm?) Or does this impede the fuel flow too much?

Thanks in advance!

[DomP]

I can't see how a slightly longer line would make any difference aside from being stupidly long

[Nurse Julie]

You need 5.5mm ID or the tube will not fit over the outlet but 5.4mm fits fine. Buy a long length of tubing from Planet Silicone on Ebay. Item number 130740225601

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[Johnny4428]

Correct length might ensure when run the correct route will avoid kinking.

[rmii]

I need it too, thanks for the question and for the answers o/

[deltarider]

Correct length might ensure when run the correct route will avoid kinking.

This ^!! Don't ask me how I know... Don't bother about the wire clips where the tubes connect to the T-joints. They are a nuisance there and for the tubes it's impossible to become loose accidentely. Personally I don't have them at the petcock either, provided I have the 5,5 mm ID tubes.

[Johnny4428]

No clips either for me.

[McCabe-Thiele (Ted)]

I fitted spring clips at the carb end whilst the carbs were off.
No clips at the tap end though as less heat and easy access.

[deltarider]

The problem with spring clips at the T-joints is, if you forget to position them correctly, their little ears block access to the #2 and #2 airscrews.