Hello fellow boaters. I have a problem with my 2002 150 hp Johnson outboard motor. I lost spark to the top right spark plug from the coil. I replaced the coil and had good spark at all six cylinders at idle but when I put boat underway the hot light and buzzer came on and engine started missing badly. The engine was not over heated but I replaced water pump propeller, installed new spark plugs and checked compression on cylinders. All were at 106-108 psi. Ran motor again and it ran good but hot light and buzzer came on after 5 minutes or so. Engine began to miss again and would not rev-up above 12-1500 rpms. Should I have replaced all three coils? Should I replace my power pack and timing sensor? Or is this engine shot? HELP HELP HELP Thanks.