ORIGINAL: speedracerntrixie
I really hope I don't come off as Mr. Poo Poo here but...........I would be very surprised if the tubes do not pull out of the cowl from engine vibration.
I wondered about that very thing, so I went back into the shop.
First, I joined the tubes and secured them to the needle screws with some heat shrink.
Then I bound the tubes together near the tips:
That should hold them.
I also hope your intention is not to make adjustments with the engine running.
As a matter of fact, that is my intention. Carefully.