i have a carb on my merc v6 150 middle carb pours out gas motor runs terrible. i took carb out turned it upside down and blew air with my mouth to see if floats would shut off and i can still blow air througjh gas inlet on carb. took carb bottom off then turned float bowl upside down again, this time i could not blow air through gas inlet on carb. do i need to adjust my floats. ?