Timex Pool timer

Can someone please help me wire my pool timer, heres what I got: Two wires coming from a 20 amp GFI breaker, running approximately 125 feet,Iinstalled a Timex timing device, which I purchased at HD. The timer has two poles on the left that say line in (power) on both screws which is also marked (S1 left screw,S2 right screw). On the right of the box it says line out (load) on both screws which is marked (L1 left screw, L2 right screw). Total of 4 screws in the box. Two wires (from breaker box, one black and one white) coming from my house. Two wires (from timer to pump, one black and one white) going from the timer to the pool pump. All grounds from the panel to the timer, to the pumped are grounded. Please help! Timex has no tech support. Thanks: alt e-mail: mark.woodruff@knox.army.mil

Mark l. woodruff