My 87 Motomarina Raven seems to be having a bit of a problem. I haven't yet gotten it started because of a spark plug issue. The spark plug that was in the moped was missing the top, so I went to the local hardware store and bought the same exact spark plug. It won't fit up into the spark plug wire cap. I am not sure if there is an old tip stuck in the cap or if I'm just using the wrong plug. Can anyone post a pic of what a coil wire looks like on the inside or tell me if using the wrong spark plug will harm my engine?? Thanks so much.