Having Fuel line probs?????

[Wags]

Hey guys, I have an older Ranger fishing boat with a 150hp Merc on it. Yesterday we were out fishing and after the initial take-off and a few other start-ups to make smaller moves.....it was running great, then all of a sudden it just stalled out. Could not get it started, primer ball would not firm up and it seamed it was not getting any or enough fuel, or we were out of gas. (Guages are not reliable on this thing) It was turning over strong, so not a battery issue. So we took it to put gas in it this morn and it seemed to top out on 1 tank after just taking in a few gallons, so I ruled out the tanks were empty. I tried to squeeze the primer ball and still nothing, seemed to be getting no fuel yet. We took off the gas line connection to the OB, looked at it (as if it was magically gonna tell us something) and put it back on, then tried the ball again and it firmed up immidiately. So we took it to the lake, started right up and ran it around on both tanks, seemed fine? Then same thing happened and could not get it started,...no firmness in primer ball ect. Any ideas???? Fuel filter?? bad primer ball?? air in fuel lines? Vapor look??? The problem seems to be between the tanks and the motor...runs great as long as it was getting fuel??