Leaderboard

I don't know what this bike is but I'd doubt that nick in the side of the plug was caused by the piston. If a piston hits a plug it's nearly always right on the end of the plug, and it closes up the plug gap. That might have been hit by a valve at some time, and it might have been like that for years or since new. I wouldn't worry about that, but the blackness of that plug looks like burnt oil to me. It would pay to check the compression.

Too much advance breaks compression rings and destroys big end bearings.. It doesn't have much effect on temperature. Coils don't affect the timing. You have about twice the advance your bike is meant to have at idle speed, and more than it's meant to have all through the range. Manufacturers have worked out how much advance engines can stand, and what's best for them, and trying to better all the years and years of testing and accumulated knowledge isn't a good idea. You should try to tune it close as you can to specs. The consequences will be dire if you don't.