I am new to boating and I have a 1976 Mercury 1150 that would not start. I checked the spark and it was not getting spark so I checked another plug and it was getting spark so I tested the first one and then it was getting spark. The engine started after I put the plugs back in. the engine ran for a short time and died and would not start. I kept checking the spark in different plugs until it showed spark then the engine would run for a while. This happened several times. I am not sure how to locate the problem when sometimes I have spark and sometimes I do not. Does anyone know what might cause the spark to work part of the time but not all of the time?
