I am working on a 1964 Kawasaki 90 cc J1 bike. I had the primary coil, ignition coil, condenser and point all checked and they are all working. When I test for spark, there's light when I clip the tester to the engine body. However, when I clip it to the spark plug, there's no spark. The spark plug is new and I bought the exact type recommended by the manufacturer. Also, when I test the spark plug against the engine body for spark, there's no spark either. Can someone help me diagnose the problem? Is the spark not strong enough under compression? Thanks.