1988 Bayliner 2.3 omc. The boat runs great for 20-30 minutes or so and then it starts to cut out for just a sec. The more I run the boat the worse it gets until it is cutting out every 5-10 seconds. It isnt a sputter....its like you shut the motor off and on real quick. It has a lanyard kill switch but I bypassed it with no change. Bad coil?