Barnone , your brains seem fine to me, I aim to pick them as much as I can.

I read somewhere here that the motor power peaks at a lower rpm than 8000. Can't remember where it said but I do know that at about 2/3 throttle I hit a sweet spot and any thing more it starts to vibrate and act up. Where I live it is dry and dusty. I often find myself going through clouds of wind swept dust or back wash from cars coming out onto the highway. The chicken wire air filter that came with the bike had me worried so I got a filter that is way denser and I'm sure it restricts the air flow some. By the looks of my plug the carb mix is perfect.

I think I'm going to do the rear sprocket change next. Besides the sprocket is all I need is the 10" snap ring pliers and the chain breaker as far as special tools?