Hey guys, I have a Sig King Kobra with a Super Tiger .61. I just brought the plane out of a six year retirement to find that it has the same problem now as it did then. The problem is that I keep getting air bubbles in the fuel line. The plane runs fine long enough to tune the engine and fly for a minute or so, then it begins to "surge" and lose power all togehter, then die. Before I put the plane away six years ago, I replaced the tank and all fuel lines with no improvement. I also tried different amounts of foam rubber around the tank. I have had it sandwiched in very tight, I have tried no foam at all, and I have tried everything in between. No luck. Someone said try a fuel filter. Tried that. Still no luck. Well, I tried it at home yesterday and it seemed fine, I took it to the field this morning, made a few last minute needle valve adjustments, and took off. Same as always, ran like a striped monkey for about a minute, then began to surge and finally died and gave me a very good test of my skills! (Died in a really bad place). I am out of ideas. Is there anyway that this could be anything to do with the motor or does it have to be a fuel system problem? My father did have one suggestion that I will try if none of you guys have any other ideas. I have the brass tubing from the tank coming out of the front of the firewall to make tubing replacement easy and the holes in the firewall are just large enough for the tubing. Could the vibration from the firewall into the brass tubes be causing these bubbles? I guess I will drill the holes out larger so that the tubing doesn't rest on the firewall. The KK is way to good of an airplane to let sit because of this, but it is a very frustrating problem. I remembered today for the minute or so that I got to fly it just how great it flies. Could any of you guys shed some light on this for me? Thanks a lot in advance.

Zach