I have a MS 460 that will not start. It was not producing spark. Now it does intermittently with a different coil. The second coil is from another 460 that was running but cylinder went bad. Will not even try to start with carb cleaner. Done leakdown test also and had a small leak at the decompression valve. Cleaned and tightened it. It was after all of this when I noticed the intermittent spark. Before then I was getting a good blue spark. Tested with a spark tester.