I have a 15 ' MO-ARK BOAT WITH A BAD 1987 MERC 25 HP MOTOR. i WANT TO REPLACE IT WITH A 1973 merc 650, 65 hp motor. my problem is the wiring cable to the throttle-starter controls on the boat.The 650 has 7 wires, no plug, and the 25 has a plug with 8 leads. should the color code on the wires...