Hello again, I have cranked and run my engine. Have about 20 minutes on it. It is an O-200 with a Marvel MA-3SPA # 10-4894 The float is sticking and the pump plunger is dried out. It is obvious that I will need another carb. I have the tank level set at the location that it will be in the plane. The engine is stumbling when throttle is gradually applied but when I quickly firewall the throttle it does OK. But----after about 10 seconds the engine goes lean and will die if not returned to lower rpm, or to idle. I can raise the tank 5" and the engine runs fine. Last year there was some talk about "HEAD PRESSURE" or fuel pressure to the carb. I do believe that this is my problem. Is there someone that can give me a part # of the Marvel carb. that will work on the Fly Baby? THANKZ, "Steze" http://community.webtv.net/smlangford/StevesFlyBaby