Air in fuel line

[Mark3Cam]

Did a prelim test of an original 68 Scrambler tank to see if she would hold fuel after all the repairs. Filled it up and found a single pin hold I thought I had gotten…anyhoo not too bad and have since made repair. While I was draining through the new petcocks and lines I noticed the primary fuel line side has all sorts of little bubbles feeding down with the fuel but the other line did not. What could be the cause of this? Will it effect how the bike runs when I get there? Could one of my new fuel petcocks be faulty?

[Jordan]

That's a curious thing.
Is it happening with the fuel tap on both main and reserve?
If only on reserve, maybe air is getting in from the higher main tube?

[Mark3Cam]

Reserve actually makes the bubbles even finer. It is a 1/4” tube and a band clamp that is not small enough for the application. You figure it is sucking air as a result of the fit? Zero leaks of fuel from it tho. Went I coated the tank with a fuel resistant epoxy I applied it on the thick side. I had to drill through roughly 3/16” plus before installing the petcocks. If a portion of the filter length of the petcock is below deck as it were in the tank would this create some sort of vortex for air?

[Mark3Cam]

To clarify as well the pin hole was high on the tank on the side of the line producing the bubbles. I had to drain while it was leaking before being able to repatch. Perhaps it won’t do it when all is fuel tight? Guess I’ll find out tomorrow