I have a 1989 Merc 50hp which runs fine at 3/4 throttle. full throttle, bogs down as if not enough fuel. I have old metal tanks, could it be the tank valves?, primer bulb?. I have already cleaned and rebuilt carbs. fuel pump diaphram?
JMS, It could be any or all of them. I will presume the carb floats are set properly. <br /><br />You have either a fuel restriction or a weak fuel pump. First I would make sure the gas tanks have clean screens in the fuel pickup tubes. Next look for any screens in the fuel system of the motor. There are usually some in the carb covers, and maybe in the fuel pump(s). Next I would rebuild the fuel pump(s). They are usually pretty cheap to repair. <br /><br />I think a bad primer bulb is last to check/replace
