I have a Tee Dee .049 with Kustom Kraftsmanship needle, crankcase pressure backplate, and cylinder shims installed in a GLH. When I was flying it last summer, I was unable to get a steady needle setting. Whenever I thought I had a good needle setting, holding the nose up just a few degrees prior to launch would cause the engine to slow down (leaning out?); when returned to level, engine would resume "normal" operation. Same happens while flying, hence climbing was very difficult and engine would usually quit at about 1/2 tank.

The airplane is using a 2 oz. hard tank, 30% heli fuel w/ some castor added, and a Cox 5X4 nylon. I'm pretty sure the tank and plumbing are sound because I set up two different Tee Dees for a friend w/o pressure and they both pulled the airplane (used as a testbed) along much better thru an entire tankful than what I can achieve with my modded engine. I have a piece of fuel tubing over the union of the needle and plastic fitting because I'm leery of air leaks. Plastic carb body was replaced because it cracked causing a previous problem. I checked the pressure backplate fitting for daylight when sighting thru hole when I tore down engine to clean it up. New plug - same problem.

Hoping someone recognizes symptom described and can suggest remedy...