Pantz,
No I haven't had to change my wires. I changed my plugs because my engine was slightly bogging while trimming up or down on plane. Believe it or not, closing the plug gap slightly corrected this problem. I found an old thread on here that addressed the issue and the problem was caused by the power drain on the system when using the trim motor. I don't remember the plug number off the top of my head but I can tell you it is the direct replacement for the original plugs that champion no longer produces. Same plug, different number than in 1992.
This is a late suggestion, but with reference to the oily threads on a couple of your plugs. I would suspect that they weren't tight due to the difficulty in accessing them. Some folks just don't put in the effort or are limited by their tool selection to properly torque them down. I had the same issue on my engine and the 2 plugs with oily threads were barely torqued beyond hand tight. Loose plug = compression leak, low chamber temp, incomplete burn, low cylinder temp, rings not warm enough to fully seal . I pulled those plugs on mine again after running it for 15 hours and they looked fine, no more oil.
