HELP I need some help please. I just got this boat and it has not been ran for aleast 10 years. At first I didn't get a spark, so I went and bought a use cdi box and rotor. I got spark and it ran fine for about 5-10 mins. then it would die.If I waited about 30 mins. it would start back up so it was overheating, So I changed the impeller. But now I can not get a spark again. the motor is a 1975-1977 chrysler model # 757HB Ser. # 14315 PLEASE HELP 