Remember that as we make different maneuvers in the sky, even our normal working tanks can have a clunk that might suck in air as it falls back into where the fuel might be.

True, if one flight you have no bubbles and then a different similar flight you have bubbles, its definately time to check your fuel system.

Here is a good way.

1. Unhook the festo fitting from your P-60 and put that end in something that can drain and hold your entire fuel volume in your airplane

2. Plug in your GSU

3. Go to test menu and go to Prime fuel tubing

4. Press the start button and then increase (with the "+" button) the pump voltage to atleast 4V (I would recommend 0.5 volts ABOVE max pump voltage at full throttle, for a Titan max voltage is 3.5-3.75 V, for a P-200 I understand it can be as high as 6v, I'm not sure about a P-60, but I think 4 volts would be enough)

5. Watch for bubbles in your UAT. If you get some on the ground, you got a leak. Don't fly until you find it.

Raf