Chainsaw Repair

I've seen those, I found out why my saw kickin so bad, the oil I thought was so good may not have been. It is 80% senthetic an 20% caster and I was mixing a little heavy, thought that would be good. 91 octane pure gas too. Carbon built up in the combustion chamber down the piston. The whole exaust side of piston was black, rings stuck and kinda gooy buildup in exhaust port. May have had 8hrs on it, all milling. Got my 038 too but I caught it before any problems.