I have a 140 DZ that has about 5 gallons through it and it has just recently started a new problem. I make it through 1/2 of the masters pattern with the motor running great until the top hat with 3 of 4 up, 1/2 down where it dies when I push up the power. If it doesn't die there it dies in the next maneuver. I have replaced all of the fuel tubing including the clunk line (which was fine), tried new plugs, increased the idle speed all with no consistant success. About every fourth flight, it runs all of the way through. If I do the top hat with a full tank, no problem, so this leads me to believe it is a fuel draw problem with about half a tank. I am running a 20 oz Tettra with the gray foam clunk. I guess I could go with a bladder type tank, or use a header tank to fix the problem, but why did it only start doing this in the last week or two. Any suggestions I might be overlooking? The idle is very consistant on the ground and for the first half of the flight.

Thanks,

Jeff