I plan to splice new connectors into the fuel line of my 1200 Sport. I bought chrome plated brass connectors, made by CPC - check out CPC, they are a global manufacturer making quality connectors. There may be a local supplier in your country. I have not installed mine yet but those I have have a 1/4" ID (6.4mm). Importantly, select connectors that use ethanol-resistant VITROL seals. The CPC connectors have automatic shut-off valves on disconnection.
The CPC parts I have are items LCD170-04V and LCD220-04V. The "V" is important, it denotes Vitrol units.
Tony