Here is the situation: New OS 25 FX engine on a test stand in upright position. Tank has a good seal, clunk and vent line properly installed and hooked up. Tank midline is even with the needle valve. Needle valve closed then opened 1 1/2 turns. Prime the engine, connect glow starter, flip it a few times and the carb fills up with fuel and runs out the carb opening. Any suggestions appreciated.