1987 115 mariner no spark
Serial Number: 0B217412 Model Number: 7115747 1987 115 mariner L6 no spark on number 3 and intermittent on 5 . The plugs and wires are new. The 1,3,5 cyl all go through the upper box could this box be bad and how can I check it. Also the wiring diagram in my book seem...
