I would get rid of the 6" metallic rod. I noticed that you never mentioned shielding the spark plug cap and ignition wire and grounding the shield to the engine. This is the first thing I wound have tried. It is about the easiest thing that you can try and it can be very effective. Using aluminum foil is only temporary to see if you need to go with a fully shielded ignition wire. Ralph puts together a really good ignition system but you will never know unless you try it. If you are slow, it should take you 5 minutes to do it.