FWIW, I ran 14 AWG on mine and I have felt the wires to see if the insulation gets warm. Which it does not.
Of course a marine grade tinned wire is the best option.
Maybe it has already been stated, But I found it odd that the switches (if i remember right) were a bigger gauge than the leads coming out of the pump.
They do have butt connectors that convert. if not readily available, i have went with the butt connector to fit the larger gauge and the "double up" the smaller gauge wire when i strip it and twist it to make it fit in the butt connector better
wiring diagram - http://www.wakemakers.com/catalog/pr...29/image/1079/