Have 1980 panther rebuilt fuel pump that is run off of suction line last year. This year it will not start replaced fuel and suction line. filled fuel line with fuel and started right away. there is small amount of suction when I put my finger over suction line. It will run fine with fuel in the line but will not pull fuel out of tank. Does anyone know how much suction there should be on that line or if Fuel pump might need rebuilt again. Thanks for any help.