I have a gas engine that is new off a gas scooter and it seems to knock or ping,is this what everyone is refering to as detonation ?Can I just shim the head and lower the compresion?I have never had this problem on any of my airplanes but then again I didn't get them from china either.
ps I took it apart and found nothing wrong with crank and bearings I even tried changing the carb and running it so rich it would barely run and still pings ,could this be timing ?there is no way to adjust timing .

Darin