I have a 1974 115 hp 6cyl mercury outboard, it has 3 carbs that are backdraft style. I can remove the top of the carbs that hold the needle and seat, and the float and have checked them with my micrometer and have set them by the book (so i think) but when i squeeze the bulb really hard they will drip some fuel from the front of the carbs. and when the engine is tilted they will leak fuel out also, Im thinking because the floats are sliding inside the tube of the carb and hanging up alowing fuel to leak is this normal or what is the answer to fix this.