Hi, I have a 55ax that will start to lose power then dead stick about 10 min into every flight. Works great through an entire tank of fuel on the ground but not so in the air. After 10 min I'm @ a 1/2 tank of fuel and I'm wondering if this might be a foaming fuel problem. The tank is isolated with foam but the neck goes through the firewall and has a hard piece of rubber that holds it in place, thinking about buying a tank that doesnt do this. This sound like a good idea? Anyone had a problem like this?

My first thought is to check the internal tank plumbing. A hole in the fuel line at the copper tubeing or a crack in the copper tubeing with give this very effect. When 1/2 the fuel is gone the hole/crack is exposed to air and the fuel draw goes lean killing the engine.

Bruce

Thanks for the reply. I think im going to replace the tank & replumb everything while I have it apart. It's the tank that came in the kit & it has plastic tubes instead of copper, cheaply made. Maybe that's the issue.

Definately could be foaming. Try a Dubro sintered clunk/filter or the more expensive os version

also an engine will lean out in the air.
I always lean out for max rpm then back off 3 clicks