Was out trolling when at idle spped for prolonged times the engine will die when you give it gas. It wouls star back fairly easily and it would rev up in nuetral. But when you engage the trans. to move out the motor dies. Finaly got going back at dock changed water sep. and plugs. Went out again ran fine on the way back to the dock no wake zone for about 5 min. engine died at dock. Hard to get started again. When I did get it going it idled a little rough but when I reved it up in nutral it sounded fine. Could a coil be bad? How do I test them?