ok i have replaced fuel pump fuel lines, plugs wires, plugs, had the carb rebuilt. the boat last sunday ran good then when we stoped in a cove an swam went to go leave the boat ran then open it up an it bogged down an kept doing it, took the boat up the other day started fine ran good for 20 mins then it started to bogg down again an almost die an some times it did die, did this the rest of the day, what can cause this, some has said it could be the coil?