I have simplicity rider with a 12.5 hp Kohler that would quit on me. I pulled the fuel line off from the fuel pump output and didn't get much gas out. I bypassed the fuel pump and it ran fine. The tank is above the engine. Do I need to replace the $60 fuel pump or will that create any problem? I don't mow on any extended hills that the gravity system would not supply fuel to the carb. What kind of pressure or volume should that mechanical pump put out? Thanks for any input.