Hey Guys, just wanted to thank everyone who helped me "work through my problem". I ran my .91 FX today after the various mods from your suggestions and she ran great. Problem solved. I wish I could say what did it, whether it was the needle valve o-ring, or the sealant around the base of the carb, or the idle needle setting, but whatever it was it worked. Thanks again.

Just for grins and giggles, I ran 5% sig fuel (my ducted fan fuel), an OS #8 plug and a graupner 12/8 three blade prop. She will idle at 2100 rpm and max lean at 11500 rmp. I have her set at 11100 and she is pouring smoke out, after 24oz of fuel through her the head was decently cool (could keep my finger on it for a second or so). She is mounted inverted with a "pits style" muffler (diverts the exhaust straight down) and she is going into a "slightly modified" Great Planes 40 size Extra 300 ARF. HEE HEE HEE HEE...I want LOTS of vertical power!!