This seems strange but if my outboard has been sitting for a while and I add fuel to the internal tank and try to start it, it won't start. I have the fuel **** in the right position and checked to see if the carb has fuel by unscrewing the drain screw. Now if I connect the external tank and switch the fuel **** the engine will start. once the engine starts, I can switch the fuel **** to the internal fuel tank and the engine continues to run. To complicate things more. The reverse has also happened. If the external tank doesn't start the engine after several tries, all I do is to switch the fuel **** to the internal tank and the engine will start. Again once the engine starts I can switch over the the external tank. This issue just started about 6 months ago. Once the enegine is warm I can go back and forth to either tank and have no issues. FYI.... I remove the external tank and let the engine die when storing it. at the same time I also remove the internal tank and drain all the gas from it as well. Thanks for your help in advance.