Clear fuel lines

[25931]

One would be able to trace air leaks more easily with clear plastic pipes, but I'm sure that there must be a good reason for not using them.

 

[Porthandbuoy]

Clear tubing, even the stuff with spiral fibre reinforcement, tends to go brittle.

I'm not sure I would be able to see the tiny leak I'm looking for anyway.

 

[noelex]

I don't think there is any that if fuel rated, but it's good idea to have as small amount on board if you get unexplained air in the system you can substitute the clear pipe to spot bubbles. As a temporary measure the clear hose seems OK. You can also do a similar trick with a clear jar, but it's a bit harder to rig up.
So if you see some 8mm clear plastic hose buy 1m of it, that way you are guaranteed never to have an air leak and need the hose.