hard starting king cobra

[silcozot]

I hope someone can help. I have a 1991 255 sundowner and am having trouble with poor starting. This boat has a 454 distributer less ignition and seems to have an advance timming setting when I try to start and wiil sometimes kick back on the starter motor. When it finally goes it runs beutifully at all rpms and under load. I am thinking that there may be a sensor that is broken?

Thanks for any help Silcozot