I recently bought an old Murray 18/42 with no model numbers on the frame or engine. All I know is that it has a 18hp B&S opposed twin. When you look at the front of the engine the fuel pump has two nipples. One is on the left and one is on the bottom. Fuel gets to the one on the left but NOT to the one on the bottom. No fuel gets to the carb. I do not usually work on twins, so I have no Idea how the fuel system works at all. Any help or explanation at all is appreciated.