Inside the ignition wire, there is a small metal cylinder that slides over the metal end of the spark plug, making an electrical contact. If you were to slide the spark plug boot along the wire, so you can gain access to this part, you could make it slightly oval shaped with pliers. Not too much, just squeeze it a little, so it fits over the spark plug more tightly. Then slide the boot back into position, and you should have a good connection.

Post all of the numbers off of you engine, please....