I went out with my 91 FX last night and did some more testing. The 46 FX does the same thing. Both do as you are saying. The conclusion is that the remote needle is leaking somewhere. There is no air in the main fuel line, no bubbling in the tank, and a ton of air in the line from the needle to the carb. Every engine I have run with the remote needle has this problem. I have a letter in to the manager at hobbico about it and will let you know what I find out. I am really close to the end of my patients with these engines. I have a lot of them and they all do it. Really close to dumping all of them and going to a different brand. Hate to do that but man is it frusterating. We will see what OS says. My next step is to put a different engine on the plane and not change the fuel system and see what happens. I put the engine on a different plane with a new fuel system and the problem moved with it so I know it is the engine. The remote needle is a pain in the butt and I won't buy another engine with one.

Anyone know of a good carb that fits the 91FX with no remote needle?