Thank for your input Turk1. Although it requires some more attention, I will empty the tank after each flight, and fill it up just before starting the engine. I have not a stand to rest the plane inclined, and also. I know the bleeding will come from the pressure tap in the muffler (that can be strangled, any how). I completed four tanks to beak - in this week end, and the engine looks more reliable, although without any doubt, it is very sensitive to the needle setting (high end).