eney one tell me how to hook up a tack on a 1967 merc.500 50hp my boat had a 30 hp nisson and i put a 50 hp 1967 merc.500 on it the tack in the dash has 4 contacks on it i think # 1 says b+ and #2said not used and #3 says g for tack and #4 says ground i think #3 is to hook to motor but where .there was a paper in the tack and this is all it says thanks the 30 hp nisson was a 1989 modle.
